6146 lines
213 KiB
C
6146 lines
213 KiB
C
/*
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LodePNG version 20150418
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Copyright (c) 2005-2015 Lode Vandevenne
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This software is provided 'as-is', without any express or implied
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warranty. In no event will the authors be held liable for any damages
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arising from the use of this software.
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute it
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freely, subject to the following restrictions:
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1. The origin of this software must not be misrepresented; you must not
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claim that you wrote the original software. If you use this software
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in a product, an acknowledgment in the product documentation would be
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appreciated but is not required.
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2. Altered source versions must be plainly marked as such, and must not be
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misrepresented as being the original software.
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3. This notice may not be removed or altered from any source
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distribution.
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*/
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/*
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The manual and changelog are in the header file "lodepng.h"
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Rename this file to lodepng.cpp to use it for C++, or to lodepng.c to use it for C.
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*/
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#include "lodepng.h"
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#include <stdio.h>
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#include <stdlib.h>
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#ifdef LODEPNG_COMPILE_CPP
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#include <fstream>
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#endif /*LODEPNG_COMPILE_CPP*/
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#if defined(_MSC_VER) && (_MSC_VER >= 1310) /*Visual Studio: A few warning types are not desired here.*/
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#pragma warning( disable : 4244 ) /*implicit conversions: not warned by gcc -Wall -Wextra and requires too much casts*/
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#pragma warning( disable : 4996 ) /*VS does not like fopen, but fopen_s is not standard C so unusable here*/
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#endif /*_MSC_VER */
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const char* LODEPNG_VERSION_STRING = "20150418";
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/*
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This source file is built up in the following large parts. The code sections
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with the "LODEPNG_COMPILE_" #defines divide this up further in an intermixed way.
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-Tools for C and common code for PNG and Zlib
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-C Code for Zlib (huffman, deflate, ...)
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-C Code for PNG (file format chunks, adam7, PNG filters, color conversions, ...)
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-The C++ wrapper around all of the above
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*/
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/*The malloc, realloc and free functions defined here with "lodepng_" in front
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of the name, so that you can easily change them to others related to your
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platform if needed. Everything else in the code calls these. Pass
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-DLODEPNG_NO_COMPILE_ALLOCATORS to the compiler, or comment out
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#define LODEPNG_COMPILE_ALLOCATORS in the header, to disable the ones here and
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define them in your own project's source files without needing to change
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lodepng source code. Don't forget to remove "static" if you copypaste them
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from here.*/
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#ifdef LODEPNG_COMPILE_ALLOCATORS
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static void* lodepng_malloc(size_t size)
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{
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return malloc(size);
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}
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static void* lodepng_realloc(void* ptr, size_t new_size)
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{
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return realloc(ptr, new_size);
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}
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static void lodepng_free(void* ptr)
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{
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free(ptr);
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}
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#else /*LODEPNG_COMPILE_ALLOCATORS*/
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void* lodepng_malloc(size_t size);
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void* lodepng_realloc(void* ptr, size_t new_size);
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void lodepng_free(void* ptr);
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#endif /*LODEPNG_COMPILE_ALLOCATORS*/
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/* ////////////////////////////////////////////////////////////////////////// */
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/* ////////////////////////////////////////////////////////////////////////// */
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/* // Tools for C, and common code for PNG and Zlib. // */
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/* ////////////////////////////////////////////////////////////////////////// */
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/* ////////////////////////////////////////////////////////////////////////// */
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/*
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Often in case of an error a value is assigned to a variable and then it breaks
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out of a loop (to go to the cleanup phase of a function). This macro does that.
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It makes the error handling code shorter and more readable.
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Example: if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(83);
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*/
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#define CERROR_BREAK(errorvar, code)\
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{\
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errorvar = code;\
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break;\
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}
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/*version of CERROR_BREAK that assumes the common case where the error variable is named "error"*/
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#define ERROR_BREAK(code) CERROR_BREAK(error, code)
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/*Set error var to the error code, and return it.*/
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#define CERROR_RETURN_ERROR(errorvar, code)\
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{\
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errorvar = code;\
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return code;\
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}
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/*Try the code, if it returns error, also return the error.*/
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#define CERROR_TRY_RETURN(call)\
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{\
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unsigned error = call;\
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if(error) return error;\
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}
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/*Set error var to the error code, and return from the void function.*/
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#define CERROR_RETURN(errorvar, code)\
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{\
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errorvar = code;\
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return;\
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}
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/*
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About uivector, ucvector and string:
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-All of them wrap dynamic arrays or text strings in a similar way.
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-LodePNG was originally written in C++. The vectors replace the std::vectors that were used in the C++ version.
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-The string tools are made to avoid problems with compilers that declare things like strncat as deprecated.
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-They're not used in the interface, only internally in this file as static functions.
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-As with many other structs in this file, the init and cleanup functions serve as ctor and dtor.
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*/
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#ifdef LODEPNG_COMPILE_ZLIB
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/*dynamic vector of unsigned ints*/
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typedef struct uivector
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{
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unsigned* data;
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size_t size; /*size in number of unsigned longs*/
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size_t allocsize; /*allocated size in bytes*/
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} uivector;
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static void uivector_cleanup(void* p)
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{
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((uivector*)p)->size = ((uivector*)p)->allocsize = 0;
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lodepng_free(((uivector*)p)->data);
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((uivector*)p)->data = NULL;
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}
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/*returns 1 if success, 0 if failure ==> nothing done*/
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static unsigned uivector_reserve(uivector* p, size_t allocsize)
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{
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if(allocsize > p->allocsize)
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{
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size_t newsize = (allocsize > p->allocsize * 2) ? allocsize : (allocsize * 3 / 2);
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void* data = lodepng_realloc(p->data, newsize);
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if(data)
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{
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p->allocsize = newsize;
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p->data = (unsigned*)data;
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}
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else return 0; /*error: not enough memory*/
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}
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return 1;
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}
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/*returns 1 if success, 0 if failure ==> nothing done*/
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static unsigned uivector_resize(uivector* p, size_t size)
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{
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if(!uivector_reserve(p, size * sizeof(unsigned))) return 0;
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p->size = size;
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return 1; /*success*/
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}
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/*resize and give all new elements the value*/
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static unsigned uivector_resizev(uivector* p, size_t size, unsigned value)
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{
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size_t oldsize = p->size, i;
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if(!uivector_resize(p, size)) return 0;
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for(i = oldsize; i < size; ++i) p->data[i] = value;
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return 1;
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}
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static void uivector_init(uivector* p)
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{
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p->data = NULL;
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p->size = p->allocsize = 0;
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}
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#ifdef LODEPNG_COMPILE_ENCODER
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/*returns 1 if success, 0 if failure ==> nothing done*/
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static unsigned uivector_push_back(uivector* p, unsigned c)
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{
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if(!uivector_resize(p, p->size + 1)) return 0;
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p->data[p->size - 1] = c;
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return 1;
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}
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#endif /*LODEPNG_COMPILE_ENCODER*/
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#endif /*LODEPNG_COMPILE_ZLIB*/
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/* /////////////////////////////////////////////////////////////////////////// */
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/*dynamic vector of unsigned chars*/
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typedef struct ucvector
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{
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unsigned char* data;
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size_t size; /*used size*/
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size_t allocsize; /*allocated size*/
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} ucvector;
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/*returns 1 if success, 0 if failure ==> nothing done*/
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static unsigned ucvector_reserve(ucvector* p, size_t allocsize)
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{
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if(allocsize > p->allocsize)
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{
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size_t newsize = (allocsize > p->allocsize * 2) ? allocsize : (allocsize * 3 / 2);
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void* data = lodepng_realloc(p->data, newsize);
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if(data)
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{
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p->allocsize = newsize;
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p->data = (unsigned char*)data;
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}
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else return 0; /*error: not enough memory*/
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}
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return 1;
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}
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/*returns 1 if success, 0 if failure ==> nothing done*/
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static unsigned ucvector_resize(ucvector* p, size_t size)
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{
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if(!ucvector_reserve(p, size * sizeof(unsigned char))) return 0;
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p->size = size;
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return 1; /*success*/
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}
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#ifdef LODEPNG_COMPILE_PNG
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static void ucvector_cleanup(void* p)
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{
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((ucvector*)p)->size = ((ucvector*)p)->allocsize = 0;
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lodepng_free(((ucvector*)p)->data);
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((ucvector*)p)->data = NULL;
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}
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static void ucvector_init(ucvector* p)
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{
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p->data = NULL;
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p->size = p->allocsize = 0;
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}
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#ifdef LODEPNG_COMPILE_DECODER
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/*resize and give all new elements the value*/
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static unsigned ucvector_resizev(ucvector* p, size_t size, unsigned char value)
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{
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size_t oldsize = p->size, i;
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if(!ucvector_resize(p, size)) return 0;
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for(i = oldsize; i < size; ++i) p->data[i] = value;
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return 1;
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}
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#endif /*LODEPNG_COMPILE_DECODER*/
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#endif /*LODEPNG_COMPILE_PNG*/
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#ifdef LODEPNG_COMPILE_ZLIB
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/*you can both convert from vector to buffer&size and vica versa. If you use
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init_buffer to take over a buffer and size, it is not needed to use cleanup*/
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static void ucvector_init_buffer(ucvector* p, unsigned char* buffer, size_t size)
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{
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p->data = buffer;
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p->allocsize = p->size = size;
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}
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#endif /*LODEPNG_COMPILE_ZLIB*/
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#if (defined(LODEPNG_COMPILE_PNG) && defined(LODEPNG_COMPILE_ANCILLARY_CHUNKS)) || defined(LODEPNG_COMPILE_ENCODER)
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/*returns 1 if success, 0 if failure ==> nothing done*/
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static unsigned ucvector_push_back(ucvector* p, unsigned char c)
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{
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if(!ucvector_resize(p, p->size + 1)) return 0;
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p->data[p->size - 1] = c;
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return 1;
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}
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#endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/
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/* ////////////////////////////////////////////////////////////////////////// */
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#ifdef LODEPNG_COMPILE_PNG
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#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
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/*returns 1 if success, 0 if failure ==> nothing done*/
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static unsigned string_resize(char** out, size_t size)
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{
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char* data = (char*)lodepng_realloc(*out, size + 1);
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if(data)
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{
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data[size] = 0; /*null termination char*/
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*out = data;
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}
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return data != 0;
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}
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/*init a {char*, size_t} pair for use as string*/
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static void string_init(char** out)
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{
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*out = NULL;
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string_resize(out, 0);
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}
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/*free the above pair again*/
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static void string_cleanup(char** out)
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{
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lodepng_free(*out);
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*out = NULL;
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}
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static void string_set(char** out, const char* in)
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{
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size_t insize = strlen(in), i;
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if(string_resize(out, insize))
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{
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for(i = 0; i != insize; ++i)
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{
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(*out)[i] = in[i];
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}
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}
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}
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#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
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#endif /*LODEPNG_COMPILE_PNG*/
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/* ////////////////////////////////////////////////////////////////////////// */
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unsigned lodepng_read32bitInt(const unsigned char* buffer)
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{
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return (unsigned)((buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3]);
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}
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#if defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)
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/*buffer must have at least 4 allocated bytes available*/
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static void lodepng_set32bitInt(unsigned char* buffer, unsigned value)
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{
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buffer[0] = (unsigned char)((value >> 24) & 0xff);
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buffer[1] = (unsigned char)((value >> 16) & 0xff);
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buffer[2] = (unsigned char)((value >> 8) & 0xff);
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buffer[3] = (unsigned char)((value ) & 0xff);
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}
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#endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/
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#ifdef LODEPNG_COMPILE_ENCODER
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static void lodepng_add32bitInt(ucvector* buffer, unsigned value)
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{
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ucvector_resize(buffer, buffer->size + 4); /*todo: give error if resize failed*/
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lodepng_set32bitInt(&buffer->data[buffer->size - 4], value);
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}
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#endif /*LODEPNG_COMPILE_ENCODER*/
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/* ////////////////////////////////////////////////////////////////////////// */
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/* / File IO / */
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/* ////////////////////////////////////////////////////////////////////////// */
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#ifdef LODEPNG_COMPILE_DISK
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unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename)
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{
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FILE* file;
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long size;
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/*provide some proper output values if error will happen*/
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*out = 0;
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*outsize = 0;
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file = fopen(filename, "rb");
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if(!file) return 78;
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/*get filesize:*/
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fseek(file , 0 , SEEK_END);
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size = ftell(file);
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rewind(file);
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/*read contents of the file into the vector*/
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*outsize = 0;
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*out = (unsigned char*)lodepng_malloc((size_t)size);
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if(size && (*out)) (*outsize) = fread(*out, 1, (size_t)size, file);
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fclose(file);
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if(!(*out) && size) return 83; /*the above malloc failed*/
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return 0;
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}
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/*write given buffer to the file, overwriting the file, it doesn't append to it.*/
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unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename)
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{
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FILE* file;
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file = fopen(filename, "wb" );
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if(!file) return 79;
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fwrite((char*)buffer , 1 , buffersize, file);
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fclose(file);
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return 0;
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}
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#endif /*LODEPNG_COMPILE_DISK*/
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/* ////////////////////////////////////////////////////////////////////////// */
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/* ////////////////////////////////////////////////////////////////////////// */
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/* // End of common code and tools. Begin of Zlib related code. // */
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/* ////////////////////////////////////////////////////////////////////////// */
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/* ////////////////////////////////////////////////////////////////////////// */
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#ifdef LODEPNG_COMPILE_ZLIB
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#ifdef LODEPNG_COMPILE_ENCODER
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/*TODO: this ignores potential out of memory errors*/
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#define addBitToStream(/*size_t**/ bitpointer, /*ucvector**/ bitstream, /*unsigned char*/ bit)\
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{\
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/*add a new byte at the end*/\
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if(((*bitpointer) & 7) == 0) ucvector_push_back(bitstream, (unsigned char)0);\
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/*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/\
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(bitstream->data[bitstream->size - 1]) |= (bit << ((*bitpointer) & 0x7));\
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++(*bitpointer);\
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}
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static void addBitsToStream(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits)
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{
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size_t i;
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for(i = 0; i != nbits; ++i) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> i) & 1));
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}
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static void addBitsToStreamReversed(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits)
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{
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size_t i;
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for(i = 0; i != nbits; ++i) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> (nbits - 1 - i)) & 1));
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}
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#endif /*LODEPNG_COMPILE_ENCODER*/
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#ifdef LODEPNG_COMPILE_DECODER
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#define READBIT(bitpointer, bitstream) ((bitstream[bitpointer >> 3] >> (bitpointer & 0x7)) & (unsigned char)1)
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static unsigned char readBitFromStream(size_t* bitpointer, const unsigned char* bitstream)
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{
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unsigned char result = (unsigned char)(READBIT(*bitpointer, bitstream));
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++(*bitpointer);
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return result;
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}
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static unsigned readBitsFromStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits)
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{
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unsigned result = 0, i;
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for(i = 0; i != nbits; ++i)
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{
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result += ((unsigned)READBIT(*bitpointer, bitstream)) << i;
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++(*bitpointer);
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}
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return result;
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}
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#endif /*LODEPNG_COMPILE_DECODER*/
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/* ////////////////////////////////////////////////////////////////////////// */
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/* / Deflate - Huffman / */
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/* ////////////////////////////////////////////////////////////////////////// */
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#define FIRST_LENGTH_CODE_INDEX 257
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#define LAST_LENGTH_CODE_INDEX 285
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/*256 literals, the end code, some length codes, and 2 unused codes*/
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#define NUM_DEFLATE_CODE_SYMBOLS 288
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/*the distance codes have their own symbols, 30 used, 2 unused*/
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#define NUM_DISTANCE_SYMBOLS 32
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/*the code length codes. 0-15: code lengths, 16: copy previous 3-6 times, 17: 3-10 zeros, 18: 11-138 zeros*/
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#define NUM_CODE_LENGTH_CODES 19
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/*the base lengths represented by codes 257-285*/
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static const unsigned LENGTHBASE[29]
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= {3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
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67, 83, 99, 115, 131, 163, 195, 227, 258};
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/*the extra bits used by codes 257-285 (added to base length)*/
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static const unsigned LENGTHEXTRA[29]
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= {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3,
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4, 4, 4, 4, 5, 5, 5, 5, 0};
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/*the base backwards distances (the bits of distance codes appear after length codes and use their own huffman tree)*/
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static const unsigned DISTANCEBASE[30]
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= {1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513,
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769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577};
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|
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/*the extra bits of backwards distances (added to base)*/
|
|
static const unsigned DISTANCEEXTRA[30]
|
|
= {0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8,
|
|
8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13};
|
|
|
|
/*the order in which "code length alphabet code lengths" are stored, out of this
|
|
the huffman tree of the dynamic huffman tree lengths is generated*/
|
|
static const unsigned CLCL_ORDER[NUM_CODE_LENGTH_CODES]
|
|
= {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
/*
|
|
Huffman tree struct, containing multiple representations of the tree
|
|
*/
|
|
typedef struct HuffmanTree
|
|
{
|
|
unsigned* tree2d;
|
|
unsigned* tree1d;
|
|
unsigned* lengths; /*the lengths of the codes of the 1d-tree*/
|
|
unsigned maxbitlen; /*maximum number of bits a single code can get*/
|
|
unsigned numcodes; /*number of symbols in the alphabet = number of codes*/
|
|
} HuffmanTree;
|
|
|
|
/*function used for debug purposes to draw the tree in ascii art with C++*/
|
|
/*
|
|
static void HuffmanTree_draw(HuffmanTree* tree)
|
|
{
|
|
std::cout << "tree. length: " << tree->numcodes << " maxbitlen: " << tree->maxbitlen << std::endl;
|
|
for(size_t i = 0; i != tree->tree1d.size; ++i)
|
|
{
|
|
if(tree->lengths.data[i])
|
|
std::cout << i << " " << tree->tree1d.data[i] << " " << tree->lengths.data[i] << std::endl;
|
|
}
|
|
std::cout << std::endl;
|
|
}*/
|
|
|
|
static void HuffmanTree_init(HuffmanTree* tree)
|
|
{
|
|
tree->tree2d = 0;
|
|
tree->tree1d = 0;
|
|
tree->lengths = 0;
|
|
}
|
|
|
|
static void HuffmanTree_cleanup(HuffmanTree* tree)
|
|
{
|
|
lodepng_free(tree->tree2d);
|
|
lodepng_free(tree->tree1d);
|
|
lodepng_free(tree->lengths);
|
|
}
|
|
|
|
/*the tree representation used by the decoder. return value is error*/
|
|
static unsigned HuffmanTree_make2DTree(HuffmanTree* tree)
|
|
{
|
|
unsigned nodefilled = 0; /*up to which node it is filled*/
|
|
unsigned treepos = 0; /*position in the tree (1 of the numcodes columns)*/
|
|
unsigned n, i;
|
|
|
|
tree->tree2d = (unsigned*)lodepng_malloc(tree->numcodes * 2 * sizeof(unsigned));
|
|
if(!tree->tree2d) return 83; /*alloc fail*/
|
|
|
|
/*
|
|
convert tree1d[] to tree2d[][]. In the 2D array, a value of 32767 means
|
|
uninited, a value >= numcodes is an address to another bit, a value < numcodes
|
|
is a code. The 2 rows are the 2 possible bit values (0 or 1), there are as
|
|
many columns as codes - 1.
|
|
A good huffmann tree has N * 2 - 1 nodes, of which N - 1 are internal nodes.
|
|
Here, the internal nodes are stored (what their 0 and 1 option point to).
|
|
There is only memory for such good tree currently, if there are more nodes
|
|
(due to too long length codes), error 55 will happen
|
|
*/
|
|
for(n = 0; n < tree->numcodes * 2; ++n)
|
|
{
|
|
tree->tree2d[n] = 32767; /*32767 here means the tree2d isn't filled there yet*/
|
|
}
|
|
|
|
for(n = 0; n < tree->numcodes; ++n) /*the codes*/
|
|
{
|
|
for(i = 0; i != tree->lengths[n]; ++i) /*the bits for this code*/
|
|
{
|
|
unsigned char bit = (unsigned char)((tree->tree1d[n] >> (tree->lengths[n] - i - 1)) & 1);
|
|
/*oversubscribed, see comment in lodepng_error_text*/
|
|
if(treepos > 2147483647 || treepos + 2 > tree->numcodes) return 55;
|
|
if(tree->tree2d[2 * treepos + bit] == 32767) /*not yet filled in*/
|
|
{
|
|
if(i + 1 == tree->lengths[n]) /*last bit*/
|
|
{
|
|
tree->tree2d[2 * treepos + bit] = n; /*put the current code in it*/
|
|
treepos = 0;
|
|
}
|
|
else
|
|
{
|
|
/*put address of the next step in here, first that address has to be found of course
|
|
(it's just nodefilled + 1)...*/
|
|
++nodefilled;
|
|
/*addresses encoded with numcodes added to it*/
|
|
tree->tree2d[2 * treepos + bit] = nodefilled + tree->numcodes;
|
|
treepos = nodefilled;
|
|
}
|
|
}
|
|
else treepos = tree->tree2d[2 * treepos + bit] - tree->numcodes;
|
|
}
|
|
}
|
|
|
|
for(n = 0; n < tree->numcodes * 2; ++n)
|
|
{
|
|
if(tree->tree2d[n] == 32767) tree->tree2d[n] = 0; /*remove possible remaining 32767's*/
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
Second step for the ...makeFromLengths and ...makeFromFrequencies functions.
|
|
numcodes, lengths and maxbitlen must already be filled in correctly. return
|
|
value is error.
|
|
*/
|
|
static unsigned HuffmanTree_makeFromLengths2(HuffmanTree* tree)
|
|
{
|
|
uivector blcount;
|
|
uivector nextcode;
|
|
unsigned error = 0;
|
|
unsigned bits, n;
|
|
|
|
uivector_init(&blcount);
|
|
uivector_init(&nextcode);
|
|
|
|
tree->tree1d = (unsigned*)lodepng_malloc(tree->numcodes * sizeof(unsigned));
|
|
if(!tree->tree1d) error = 83; /*alloc fail*/
|
|
|
|
if(!uivector_resizev(&blcount, tree->maxbitlen + 1, 0)
|
|
|| !uivector_resizev(&nextcode, tree->maxbitlen + 1, 0))
|
|
error = 83; /*alloc fail*/
|
|
|
|
if(!error)
|
|
{
|
|
/*step 1: count number of instances of each code length*/
|
|
for(bits = 0; bits != tree->numcodes; ++bits) ++blcount.data[tree->lengths[bits]];
|
|
/*step 2: generate the nextcode values*/
|
|
for(bits = 1; bits <= tree->maxbitlen; ++bits)
|
|
{
|
|
nextcode.data[bits] = (nextcode.data[bits - 1] + blcount.data[bits - 1]) << 1;
|
|
}
|
|
/*step 3: generate all the codes*/
|
|
for(n = 0; n != tree->numcodes; ++n)
|
|
{
|
|
if(tree->lengths[n] != 0) tree->tree1d[n] = nextcode.data[tree->lengths[n]]++;
|
|
}
|
|
}
|
|
|
|
uivector_cleanup(&blcount);
|
|
uivector_cleanup(&nextcode);
|
|
|
|
if(!error) return HuffmanTree_make2DTree(tree);
|
|
else return error;
|
|
}
|
|
|
|
/*
|
|
given the code lengths (as stored in the PNG file), generate the tree as defined
|
|
by Deflate. maxbitlen is the maximum bits that a code in the tree can have.
|
|
return value is error.
|
|
*/
|
|
static unsigned HuffmanTree_makeFromLengths(HuffmanTree* tree, const unsigned* bitlen,
|
|
size_t numcodes, unsigned maxbitlen)
|
|
{
|
|
unsigned i;
|
|
tree->lengths = (unsigned*)lodepng_malloc(numcodes * sizeof(unsigned));
|
|
if(!tree->lengths) return 83; /*alloc fail*/
|
|
for(i = 0; i != numcodes; ++i) tree->lengths[i] = bitlen[i];
|
|
tree->numcodes = (unsigned)numcodes; /*number of symbols*/
|
|
tree->maxbitlen = maxbitlen;
|
|
return HuffmanTree_makeFromLengths2(tree);
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
|
|
/*BPM: Boundary Package Merge, see "A Fast and Space-Economical Algorithm for Length-Limited Coding",
|
|
Jyrki Katajainen, Alistair Moffat, Andrew Turpin, 1995.*/
|
|
|
|
/*chain node for boundary package merge*/
|
|
typedef struct BPMNode
|
|
{
|
|
int weight; /*the sum of all weights in this chain*/
|
|
unsigned index; /*index of this leaf node (called "count" in the paper)*/
|
|
struct BPMNode* tail; /*the next nodes in this chain (null if last)*/
|
|
int in_use;
|
|
} BPMNode;
|
|
|
|
/*lists of chains*/
|
|
typedef struct BPMLists
|
|
{
|
|
/*memory pool*/
|
|
unsigned memsize;
|
|
BPMNode* memory;
|
|
unsigned numfree;
|
|
unsigned nextfree;
|
|
BPMNode** freelist;
|
|
/*two heads of lookahead chains per list*/
|
|
unsigned listsize;
|
|
BPMNode** chains0;
|
|
BPMNode** chains1;
|
|
} BPMLists;
|
|
|
|
/*creates a new chain node with the given parameters, from the memory in the lists */
|
|
static BPMNode* bpmnode_create(BPMLists* lists, int weight, unsigned index, BPMNode* tail)
|
|
{
|
|
unsigned i;
|
|
BPMNode* result;
|
|
|
|
/*memory full, so garbage collect*/
|
|
if(lists->nextfree >= lists->numfree)
|
|
{
|
|
/*mark only those that are in use*/
|
|
for(i = 0; i != lists->memsize; ++i) lists->memory[i].in_use = 0;
|
|
for(i = 0; i != lists->listsize; ++i)
|
|
{
|
|
BPMNode* node;
|
|
for(node = lists->chains0[i]; node != 0; node = node->tail) node->in_use = 1;
|
|
for(node = lists->chains1[i]; node != 0; node = node->tail) node->in_use = 1;
|
|
}
|
|
/*collect those that are free*/
|
|
lists->numfree = 0;
|
|
for(i = 0; i != lists->memsize; ++i)
|
|
{
|
|
if(!lists->memory[i].in_use) lists->freelist[lists->numfree++] = &lists->memory[i];
|
|
}
|
|
lists->nextfree = 0;
|
|
}
|
|
|
|
result = lists->freelist[lists->nextfree++];
|
|
result->weight = weight;
|
|
result->index = index;
|
|
result->tail = tail;
|
|
return result;
|
|
}
|
|
|
|
static int bpmnode_compare(const void* a, const void* b)
|
|
{
|
|
int wa = ((const BPMNode*)a)->weight;
|
|
int wb = ((const BPMNode*)b)->weight;
|
|
if(wa < wb) return -1;
|
|
if(wa > wb) return 1;
|
|
/*make the qsort a stable sort*/
|
|
return ((const BPMNode*)a)->index < ((const BPMNode*)b)->index ? 1 : -1;
|
|
}
|
|
|
|
/*Boundary Package Merge step, numpresent is the amount of leaves, and c is the current chain.*/
|
|
static void boundaryPM(BPMLists* lists, BPMNode* leaves, size_t numpresent, int c, int num)
|
|
{
|
|
unsigned lastindex = lists->chains1[c]->index;
|
|
|
|
if(c == 0)
|
|
{
|
|
if(lastindex >= numpresent) return;
|
|
lists->chains0[c] = lists->chains1[c];
|
|
lists->chains1[c] = bpmnode_create(lists, leaves[lastindex].weight, lastindex + 1, 0);
|
|
}
|
|
else
|
|
{
|
|
/*sum of the weights of the head nodes of the previous lookahead chains.*/
|
|
int sum = lists->chains0[c - 1]->weight + lists->chains1[c - 1]->weight;
|
|
lists->chains0[c] = lists->chains1[c];
|
|
if(lastindex < numpresent && sum > leaves[lastindex].weight)
|
|
{
|
|
lists->chains1[c] = bpmnode_create(lists, leaves[lastindex].weight, lastindex + 1, lists->chains1[c]->tail);
|
|
return;
|
|
}
|
|
lists->chains1[c] = bpmnode_create(lists, sum, lastindex, lists->chains1[c - 1]);
|
|
/*in the end we are only interested in the chain of the last list, so no
|
|
need to recurse if we're at the last one (this gives measurable speedup)*/
|
|
if(num + 1 < (int)(2 * numpresent - 2))
|
|
{
|
|
boundaryPM(lists, leaves, numpresent, c - 1, num);
|
|
boundaryPM(lists, leaves, numpresent, c - 1, num);
|
|
}
|
|
}
|
|
}
|
|
|
|
unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies,
|
|
size_t numcodes, unsigned maxbitlen)
|
|
{
|
|
unsigned error = 0;
|
|
unsigned i;
|
|
size_t numpresent = 0; /*number of symbols with non-zero frequency*/
|
|
BPMNode* leaves; /*the symbols, only those with > 0 frequency*/
|
|
|
|
if(numcodes == 0) return 80; /*error: a tree of 0 symbols is not supposed to be made*/
|
|
if((1u << maxbitlen) < numcodes) return 80; /*error: represent all symbols*/
|
|
|
|
leaves = (BPMNode*)lodepng_malloc(numcodes * sizeof(*leaves));
|
|
if(!leaves) return 83; /*alloc fail*/
|
|
|
|
for(i = 0; i != numcodes; ++i)
|
|
{
|
|
if(frequencies[i] > 0)
|
|
{
|
|
leaves[numpresent].weight = frequencies[i];
|
|
leaves[numpresent].index = i;
|
|
++numpresent;
|
|
}
|
|
}
|
|
|
|
for(i = 0; i != numcodes; ++i) lengths[i] = 0;
|
|
|
|
/*ensure at least two present symbols. There should be at least one symbol
|
|
according to RFC 1951 section 3.2.7. Some decoders incorrectly require two. To
|
|
make these work as well ensure there are at least two symbols. The
|
|
Package-Merge code below also doesn't work correctly if there's only one
|
|
symbol, it'd give it the theoritical 0 bits but in practice zlib wants 1 bit*/
|
|
if(numpresent == 0)
|
|
{
|
|
lengths[0] = lengths[1] = 1; /*note that for RFC 1951 section 3.2.7, only lengths[0] = 1 is needed*/
|
|
}
|
|
else if(numpresent == 1)
|
|
{
|
|
lengths[leaves[0].index] = 1;
|
|
lengths[leaves[0].index == 0 ? 1 : 0] = 1;
|
|
}
|
|
else
|
|
{
|
|
BPMLists lists;
|
|
BPMNode* node;
|
|
|
|
qsort(leaves, numpresent, sizeof(BPMNode), bpmnode_compare);
|
|
|
|
lists.listsize = maxbitlen;
|
|
lists.memsize = 2 * maxbitlen * (maxbitlen + 1);
|
|
lists.nextfree = 0;
|
|
lists.numfree = lists.memsize;
|
|
lists.memory = (BPMNode*)lodepng_malloc(lists.memsize * sizeof(*lists.memory));
|
|
lists.freelist = (BPMNode**)lodepng_malloc(lists.memsize * sizeof(BPMNode*));
|
|
lists.chains0 = (BPMNode**)lodepng_malloc(lists.listsize * sizeof(BPMNode*));
|
|
lists.chains1 = (BPMNode**)lodepng_malloc(lists.listsize * sizeof(BPMNode*));
|
|
if(!lists.memory || !lists.freelist || !lists.chains0 || !lists.chains1) error = 83; /*alloc fail*/
|
|
|
|
if(!error)
|
|
{
|
|
for(i = 0; i != lists.memsize; ++i) lists.freelist[i] = &lists.memory[i];
|
|
|
|
bpmnode_create(&lists, leaves[0].weight, 1, 0);
|
|
bpmnode_create(&lists, leaves[1].weight, 2, 0);
|
|
|
|
for(i = 0; i != lists.listsize; ++i)
|
|
{
|
|
lists.chains0[i] = &lists.memory[0];
|
|
lists.chains1[i] = &lists.memory[1];
|
|
}
|
|
|
|
/*each boundaryPM call adds one chain to the last list, and we need 2 * numpresent - 2 chains.*/
|
|
for(i = 2; i != 2 * numpresent - 2; ++i) boundaryPM(&lists, leaves, numpresent, maxbitlen - 1, i);
|
|
|
|
for(node = lists.chains1[maxbitlen - 1]; node; node = node->tail)
|
|
{
|
|
for(i = 0; i != node->index; ++i) ++lengths[leaves[i].index];
|
|
}
|
|
}
|
|
|
|
lodepng_free(lists.memory);
|
|
lodepng_free(lists.freelist);
|
|
lodepng_free(lists.chains0);
|
|
lodepng_free(lists.chains1);
|
|
}
|
|
|
|
lodepng_free(leaves);
|
|
return error;
|
|
}
|
|
|
|
/*Create the Huffman tree given the symbol frequencies*/
|
|
static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigned* frequencies,
|
|
size_t mincodes, size_t numcodes, unsigned maxbitlen)
|
|
{
|
|
unsigned error = 0;
|
|
while(!frequencies[numcodes - 1] && numcodes > mincodes) --numcodes; /*trim zeroes*/
|
|
tree->maxbitlen = maxbitlen;
|
|
tree->numcodes = (unsigned)numcodes; /*number of symbols*/
|
|
tree->lengths = (unsigned*)lodepng_realloc(tree->lengths, numcodes * sizeof(unsigned));
|
|
if(!tree->lengths) return 83; /*alloc fail*/
|
|
/*initialize all lengths to 0*/
|
|
memset(tree->lengths, 0, numcodes * sizeof(unsigned));
|
|
|
|
error = lodepng_huffman_code_lengths(tree->lengths, frequencies, numcodes, maxbitlen);
|
|
if(!error) error = HuffmanTree_makeFromLengths2(tree);
|
|
return error;
|
|
}
|
|
|
|
static unsigned HuffmanTree_getCode(const HuffmanTree* tree, unsigned index)
|
|
{
|
|
return tree->tree1d[index];
|
|
}
|
|
|
|
static unsigned HuffmanTree_getLength(const HuffmanTree* tree, unsigned index)
|
|
{
|
|
return tree->lengths[index];
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ENCODER*/
|
|
|
|
/*get the literal and length code tree of a deflated block with fixed tree, as per the deflate specification*/
|
|
static unsigned generateFixedLitLenTree(HuffmanTree* tree)
|
|
{
|
|
unsigned i, error = 0;
|
|
unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned));
|
|
if(!bitlen) return 83; /*alloc fail*/
|
|
|
|
/*288 possible codes: 0-255=literals, 256=endcode, 257-285=lengthcodes, 286-287=unused*/
|
|
for(i = 0; i <= 143; ++i) bitlen[i] = 8;
|
|
for(i = 144; i <= 255; ++i) bitlen[i] = 9;
|
|
for(i = 256; i <= 279; ++i) bitlen[i] = 7;
|
|
for(i = 280; i <= 287; ++i) bitlen[i] = 8;
|
|
|
|
error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DEFLATE_CODE_SYMBOLS, 15);
|
|
|
|
lodepng_free(bitlen);
|
|
return error;
|
|
}
|
|
|
|
/*get the distance code tree of a deflated block with fixed tree, as specified in the deflate specification*/
|
|
static unsigned generateFixedDistanceTree(HuffmanTree* tree)
|
|
{
|
|
unsigned i, error = 0;
|
|
unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned));
|
|
if(!bitlen) return 83; /*alloc fail*/
|
|
|
|
/*there are 32 distance codes, but 30-31 are unused*/
|
|
for(i = 0; i != NUM_DISTANCE_SYMBOLS; ++i) bitlen[i] = 5;
|
|
error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DISTANCE_SYMBOLS, 15);
|
|
|
|
lodepng_free(bitlen);
|
|
return error;
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
|
|
/*
|
|
returns the code, or (unsigned)(-1) if error happened
|
|
inbitlength is the length of the complete buffer, in bits (so its byte length times 8)
|
|
*/
|
|
static unsigned huffmanDecodeSymbol(const unsigned char* in, size_t* bp,
|
|
const HuffmanTree* codetree, size_t inbitlength)
|
|
{
|
|
unsigned treepos = 0, ct;
|
|
for(;;)
|
|
{
|
|
if(*bp >= inbitlength) return (unsigned)(-1); /*error: end of input memory reached without endcode*/
|
|
/*
|
|
decode the symbol from the tree. The "readBitFromStream" code is inlined in
|
|
the expression below because this is the biggest bottleneck while decoding
|
|
*/
|
|
ct = codetree->tree2d[(treepos << 1) + READBIT(*bp, in)];
|
|
++(*bp);
|
|
if(ct < codetree->numcodes) return ct; /*the symbol is decoded, return it*/
|
|
else treepos = ct - codetree->numcodes; /*symbol not yet decoded, instead move tree position*/
|
|
|
|
if(treepos >= codetree->numcodes) return (unsigned)(-1); /*error: it appeared outside the codetree*/
|
|
}
|
|
}
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
|
|
#ifdef LODEPNG_COMPILE_DECODER
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/* ////////////////////////////////////////////////////////////////////////// */
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/* / Inflator (Decompressor) / */
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/* ////////////////////////////////////////////////////////////////////////// */
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/*get the tree of a deflated block with fixed tree, as specified in the deflate specification*/
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static void getTreeInflateFixed(HuffmanTree* tree_ll, HuffmanTree* tree_d)
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{
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/*TODO: check for out of memory errors*/
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generateFixedLitLenTree(tree_ll);
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generateFixedDistanceTree(tree_d);
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}
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/*get the tree of a deflated block with dynamic tree, the tree itself is also Huffman compressed with a known tree*/
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static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d,
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const unsigned char* in, size_t* bp, size_t inlength)
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{
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/*make sure that length values that aren't filled in will be 0, or a wrong tree will be generated*/
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unsigned error = 0;
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unsigned n, HLIT, HDIST, HCLEN, i;
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size_t inbitlength = inlength * 8;
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/*see comments in deflateDynamic for explanation of the context and these variables, it is analogous*/
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unsigned* bitlen_ll = 0; /*lit,len code lengths*/
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unsigned* bitlen_d = 0; /*dist code lengths*/
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/*code length code lengths ("clcl"), the bit lengths of the huffman tree used to compress bitlen_ll and bitlen_d*/
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unsigned* bitlen_cl = 0;
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HuffmanTree tree_cl; /*the code tree for code length codes (the huffman tree for compressed huffman trees)*/
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if((*bp) + 14 > (inlength << 3)) return 49; /*error: the bit pointer is or will go past the memory*/
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/*number of literal/length codes + 257. Unlike the spec, the value 257 is added to it here already*/
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HLIT = readBitsFromStream(bp, in, 5) + 257;
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/*number of distance codes. Unlike the spec, the value 1 is added to it here already*/
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HDIST = readBitsFromStream(bp, in, 5) + 1;
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/*number of code length codes. Unlike the spec, the value 4 is added to it here already*/
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HCLEN = readBitsFromStream(bp, in, 4) + 4;
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if((*bp) + HCLEN * 3 > (inlength << 3)) return 50; /*error: the bit pointer is or will go past the memory*/
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HuffmanTree_init(&tree_cl);
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while(!error)
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{
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/*read the code length codes out of 3 * (amount of code length codes) bits*/
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bitlen_cl = (unsigned*)lodepng_malloc(NUM_CODE_LENGTH_CODES * sizeof(unsigned));
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if(!bitlen_cl) ERROR_BREAK(83 /*alloc fail*/);
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for(i = 0; i != NUM_CODE_LENGTH_CODES; ++i)
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{
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if(i < HCLEN) bitlen_cl[CLCL_ORDER[i]] = readBitsFromStream(bp, in, 3);
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else bitlen_cl[CLCL_ORDER[i]] = 0; /*if not, it must stay 0*/
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}
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error = HuffmanTree_makeFromLengths(&tree_cl, bitlen_cl, NUM_CODE_LENGTH_CODES, 7);
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if(error) break;
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/*now we can use this tree to read the lengths for the tree that this function will return*/
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bitlen_ll = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned));
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bitlen_d = (unsigned*)lodepng_malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned));
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if(!bitlen_ll || !bitlen_d) ERROR_BREAK(83 /*alloc fail*/);
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for(i = 0; i != NUM_DEFLATE_CODE_SYMBOLS; ++i) bitlen_ll[i] = 0;
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for(i = 0; i != NUM_DISTANCE_SYMBOLS; ++i) bitlen_d[i] = 0;
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/*i is the current symbol we're reading in the part that contains the code lengths of lit/len and dist codes*/
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i = 0;
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while(i < HLIT + HDIST)
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{
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unsigned code = huffmanDecodeSymbol(in, bp, &tree_cl, inbitlength);
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if(code <= 15) /*a length code*/
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{
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if(i < HLIT) bitlen_ll[i] = code;
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else bitlen_d[i - HLIT] = code;
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++i;
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}
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else if(code == 16) /*repeat previous*/
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{
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unsigned replength = 3; /*read in the 2 bits that indicate repeat length (3-6)*/
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unsigned value; /*set value to the previous code*/
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if(i == 0) ERROR_BREAK(54); /*can't repeat previous if i is 0*/
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if((*bp + 2) > inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
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replength += readBitsFromStream(bp, in, 2);
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if(i < HLIT + 1) value = bitlen_ll[i - 1];
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else value = bitlen_d[i - HLIT - 1];
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/*repeat this value in the next lengths*/
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for(n = 0; n < replength; ++n)
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{
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if(i >= HLIT + HDIST) ERROR_BREAK(13); /*error: i is larger than the amount of codes*/
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if(i < HLIT) bitlen_ll[i] = value;
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else bitlen_d[i - HLIT] = value;
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++i;
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}
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}
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else if(code == 17) /*repeat "0" 3-10 times*/
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{
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unsigned replength = 3; /*read in the bits that indicate repeat length*/
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if((*bp + 3) > inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
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replength += readBitsFromStream(bp, in, 3);
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/*repeat this value in the next lengths*/
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for(n = 0; n < replength; ++n)
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{
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if(i >= HLIT + HDIST) ERROR_BREAK(14); /*error: i is larger than the amount of codes*/
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if(i < HLIT) bitlen_ll[i] = 0;
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else bitlen_d[i - HLIT] = 0;
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++i;
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}
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}
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else if(code == 18) /*repeat "0" 11-138 times*/
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{
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unsigned replength = 11; /*read in the bits that indicate repeat length*/
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if((*bp + 7) > inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
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replength += readBitsFromStream(bp, in, 7);
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/*repeat this value in the next lengths*/
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for(n = 0; n < replength; ++n)
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{
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if(i >= HLIT + HDIST) ERROR_BREAK(15); /*error: i is larger than the amount of codes*/
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if(i < HLIT) bitlen_ll[i] = 0;
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else bitlen_d[i - HLIT] = 0;
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++i;
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}
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}
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else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
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{
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if(code == (unsigned)(-1))
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{
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/*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
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(10=no endcode, 11=wrong jump outside of tree)*/
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error = (*bp) > inbitlength ? 10 : 11;
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}
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else error = 16; /*unexisting code, this can never happen*/
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break;
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}
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}
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if(error) break;
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if(bitlen_ll[256] == 0) ERROR_BREAK(64); /*the length of the end code 256 must be larger than 0*/
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/*now we've finally got HLIT and HDIST, so generate the code trees, and the function is done*/
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error = HuffmanTree_makeFromLengths(tree_ll, bitlen_ll, NUM_DEFLATE_CODE_SYMBOLS, 15);
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if(error) break;
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error = HuffmanTree_makeFromLengths(tree_d, bitlen_d, NUM_DISTANCE_SYMBOLS, 15);
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break; /*end of error-while*/
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}
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lodepng_free(bitlen_cl);
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lodepng_free(bitlen_ll);
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lodepng_free(bitlen_d);
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HuffmanTree_cleanup(&tree_cl);
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return error;
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}
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/*inflate a block with dynamic of fixed Huffman tree*/
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static unsigned inflateHuffmanBlock(ucvector* out, const unsigned char* in, size_t* bp,
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size_t* pos, size_t inlength, unsigned btype)
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{
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unsigned error = 0;
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HuffmanTree tree_ll; /*the huffman tree for literal and length codes*/
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HuffmanTree tree_d; /*the huffman tree for distance codes*/
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size_t inbitlength = inlength * 8;
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HuffmanTree_init(&tree_ll);
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HuffmanTree_init(&tree_d);
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if(btype == 1) getTreeInflateFixed(&tree_ll, &tree_d);
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else if(btype == 2) error = getTreeInflateDynamic(&tree_ll, &tree_d, in, bp, inlength);
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while(!error) /*decode all symbols until end reached, breaks at end code*/
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{
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/*code_ll is literal, length or end code*/
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unsigned code_ll = huffmanDecodeSymbol(in, bp, &tree_ll, inbitlength);
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if(code_ll <= 255) /*literal symbol*/
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{
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/*ucvector_push_back would do the same, but for some reason the two lines below run 10% faster*/
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if(!ucvector_resize(out, (*pos) + 1)) ERROR_BREAK(83 /*alloc fail*/);
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out->data[*pos] = (unsigned char)code_ll;
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++(*pos);
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}
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else if(code_ll >= FIRST_LENGTH_CODE_INDEX && code_ll <= LAST_LENGTH_CODE_INDEX) /*length code*/
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{
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unsigned code_d, distance;
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unsigned numextrabits_l, numextrabits_d; /*extra bits for length and distance*/
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size_t start, forward, backward, length;
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/*part 1: get length base*/
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length = LENGTHBASE[code_ll - FIRST_LENGTH_CODE_INDEX];
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/*part 2: get extra bits and add the value of that to length*/
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numextrabits_l = LENGTHEXTRA[code_ll - FIRST_LENGTH_CODE_INDEX];
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if((*bp + numextrabits_l) > inbitlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/
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length += readBitsFromStream(bp, in, numextrabits_l);
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/*part 3: get distance code*/
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code_d = huffmanDecodeSymbol(in, bp, &tree_d, inbitlength);
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if(code_d > 29)
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{
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if(code_ll == (unsigned)(-1)) /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
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{
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/*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
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(10=no endcode, 11=wrong jump outside of tree)*/
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error = (*bp) > inlength * 8 ? 10 : 11;
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}
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else error = 18; /*error: invalid distance code (30-31 are never used)*/
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break;
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}
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distance = DISTANCEBASE[code_d];
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/*part 4: get extra bits from distance*/
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numextrabits_d = DISTANCEEXTRA[code_d];
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if((*bp + numextrabits_d) > inbitlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/
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distance += readBitsFromStream(bp, in, numextrabits_d);
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/*part 5: fill in all the out[n] values based on the length and dist*/
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start = (*pos);
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if(distance > start) ERROR_BREAK(52); /*too long backward distance*/
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backward = start - distance;
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if(!ucvector_resize(out, (*pos) + length)) ERROR_BREAK(83 /*alloc fail*/);
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if (distance < length) {
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for(forward = 0; forward < length; ++forward)
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{
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out->data[(*pos)++] = out->data[backward++];
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}
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} else {
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memcpy(out->data + *pos, out->data + backward, length);
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*pos += length;
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}
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}
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else if(code_ll == 256)
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{
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break; /*end code, break the loop*/
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}
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else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
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{
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/*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
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(10=no endcode, 11=wrong jump outside of tree)*/
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error = ((*bp) > inlength * 8) ? 10 : 11;
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break;
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}
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}
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HuffmanTree_cleanup(&tree_ll);
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HuffmanTree_cleanup(&tree_d);
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return error;
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}
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static unsigned inflateNoCompression(ucvector* out, const unsigned char* in, size_t* bp, size_t* pos, size_t inlength)
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{
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size_t p;
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unsigned LEN, NLEN, n, error = 0;
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/*go to first boundary of byte*/
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while(((*bp) & 0x7) != 0) ++(*bp);
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p = (*bp) / 8; /*byte position*/
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/*read LEN (2 bytes) and NLEN (2 bytes)*/
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if(p + 4 >= inlength) return 52; /*error, bit pointer will jump past memory*/
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LEN = in[p] + 256u * in[p + 1]; p += 2;
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NLEN = in[p] + 256u * in[p + 1]; p += 2;
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/*check if 16-bit NLEN is really the one's complement of LEN*/
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if(LEN + NLEN != 65535) return 21; /*error: NLEN is not one's complement of LEN*/
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if(!ucvector_resize(out, (*pos) + LEN)) return 83; /*alloc fail*/
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/*read the literal data: LEN bytes are now stored in the out buffer*/
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if(p + LEN > inlength) return 23; /*error: reading outside of in buffer*/
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for(n = 0; n < LEN; ++n) out->data[(*pos)++] = in[p++];
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(*bp) = p * 8;
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return error;
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}
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static unsigned lodepng_inflatev(ucvector* out,
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const unsigned char* in, size_t insize,
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const LodePNGDecompressSettings* settings)
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{
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/*bit pointer in the "in" data, current byte is bp >> 3, current bit is bp & 0x7 (from lsb to msb of the byte)*/
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size_t bp = 0;
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unsigned BFINAL = 0;
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size_t pos = 0; /*byte position in the out buffer*/
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unsigned error = 0;
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(void)settings;
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while(!BFINAL)
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{
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unsigned BTYPE;
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if(bp + 2 >= insize * 8) return 52; /*error, bit pointer will jump past memory*/
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BFINAL = readBitFromStream(&bp, in);
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BTYPE = 1u * readBitFromStream(&bp, in);
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BTYPE += 2u * readBitFromStream(&bp, in);
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if(BTYPE == 3) return 20; /*error: invalid BTYPE*/
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else if(BTYPE == 0) error = inflateNoCompression(out, in, &bp, &pos, insize); /*no compression*/
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else error = inflateHuffmanBlock(out, in, &bp, &pos, insize, BTYPE); /*compression, BTYPE 01 or 10*/
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if(error) return error;
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}
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return error;
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}
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unsigned lodepng_inflate(unsigned char** out, size_t* outsize,
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const unsigned char* in, size_t insize,
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const LodePNGDecompressSettings* settings)
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{
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unsigned error;
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ucvector v;
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ucvector_init_buffer(&v, *out, *outsize);
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error = lodepng_inflatev(&v, in, insize, settings);
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*out = v.data;
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*outsize = v.size;
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return error;
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}
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static unsigned inflate(unsigned char** out, size_t* outsize,
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const unsigned char* in, size_t insize,
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const LodePNGDecompressSettings* settings)
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{
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if(settings->custom_inflate)
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{
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return settings->custom_inflate(out, outsize, in, insize, settings);
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}
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else
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{
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return lodepng_inflate(out, outsize, in, insize, settings);
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}
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}
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#endif /*LODEPNG_COMPILE_DECODER*/
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#ifdef LODEPNG_COMPILE_ENCODER
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/* ////////////////////////////////////////////////////////////////////////// */
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/* / Deflator (Compressor) / */
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/* ////////////////////////////////////////////////////////////////////////// */
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static const size_t MAX_SUPPORTED_DEFLATE_LENGTH = 258;
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/*bitlen is the size in bits of the code*/
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static void addHuffmanSymbol(size_t* bp, ucvector* compressed, unsigned code, unsigned bitlen)
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{
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addBitsToStreamReversed(bp, compressed, code, bitlen);
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}
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/*search the index in the array, that has the largest value smaller than or equal to the given value,
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given array must be sorted (if no value is smaller, it returns the size of the given array)*/
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static size_t searchCodeIndex(const unsigned* array, size_t array_size, size_t value)
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{
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/*linear search implementation*/
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/*for(size_t i = 1; i < array_size; ++i) if(array[i] > value) return i - 1;
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return array_size - 1;*/
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/*binary search implementation (not that much faster) (precondition: array_size > 0)*/
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size_t left = 1;
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size_t right = array_size - 1;
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while(left <= right)
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{
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size_t mid = (left + right) / 2;
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if(array[mid] <= value) left = mid + 1; /*the value to find is more to the right*/
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else if(array[mid - 1] > value) right = mid - 1; /*the value to find is more to the left*/
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else return mid - 1;
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}
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return array_size - 1;
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}
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static void addLengthDistance(uivector* values, size_t length, size_t distance)
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{
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/*values in encoded vector are those used by deflate:
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0-255: literal bytes
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256: end
|
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257-285: length/distance pair (length code, followed by extra length bits, distance code, extra distance bits)
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286-287: invalid*/
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unsigned length_code = (unsigned)searchCodeIndex(LENGTHBASE, 29, length);
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unsigned extra_length = (unsigned)(length - LENGTHBASE[length_code]);
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unsigned dist_code = (unsigned)searchCodeIndex(DISTANCEBASE, 30, distance);
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unsigned extra_distance = (unsigned)(distance - DISTANCEBASE[dist_code]);
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uivector_push_back(values, length_code + FIRST_LENGTH_CODE_INDEX);
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uivector_push_back(values, extra_length);
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uivector_push_back(values, dist_code);
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uivector_push_back(values, extra_distance);
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}
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/*3 bytes of data get encoded into two bytes. The hash cannot use more than 3
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bytes as input because 3 is the minimum match length for deflate*/
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static const unsigned HASH_NUM_VALUES = 65536;
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static const unsigned HASH_BIT_MASK = 65535; /*HASH_NUM_VALUES - 1, but C90 does not like that as initializer*/
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typedef struct Hash
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{
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int* head; /*hash value to head circular pos - can be outdated if went around window*/
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/*circular pos to prev circular pos*/
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unsigned short* chain;
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int* val; /*circular pos to hash value*/
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|
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/*TODO: do this not only for zeros but for any repeated byte. However for PNG
|
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it's always going to be the zeros that dominate, so not important for PNG*/
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int* headz; /*similar to head, but for chainz*/
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unsigned short* chainz; /*those with same amount of zeros*/
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unsigned short* zeros; /*length of zeros streak, used as a second hash chain*/
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} Hash;
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static unsigned hash_init(Hash* hash, unsigned windowsize)
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{
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unsigned i;
|
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hash->head = (int*)lodepng_malloc(sizeof(int) * HASH_NUM_VALUES);
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hash->val = (int*)lodepng_malloc(sizeof(int) * windowsize);
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hash->chain = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize);
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hash->zeros = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize);
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hash->headz = (int*)lodepng_malloc(sizeof(int) * (MAX_SUPPORTED_DEFLATE_LENGTH + 1));
|
|
hash->chainz = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize);
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|
|
if(!hash->head || !hash->chain || !hash->val || !hash->headz|| !hash->chainz || !hash->zeros)
|
|
{
|
|
return 83; /*alloc fail*/
|
|
}
|
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|
|
/*initialize hash table*/
|
|
for(i = 0; i != HASH_NUM_VALUES; ++i) hash->head[i] = -1;
|
|
for(i = 0; i != windowsize; ++i) hash->val[i] = -1;
|
|
for(i = 0; i != windowsize; ++i) hash->chain[i] = i; /*same value as index indicates uninitialized*/
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|
|
for(i = 0; i <= MAX_SUPPORTED_DEFLATE_LENGTH; ++i) hash->headz[i] = -1;
|
|
for(i = 0; i != windowsize; ++i) hash->chainz[i] = i; /*same value as index indicates uninitialized*/
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void hash_cleanup(Hash* hash)
|
|
{
|
|
lodepng_free(hash->head);
|
|
lodepng_free(hash->val);
|
|
lodepng_free(hash->chain);
|
|
|
|
lodepng_free(hash->zeros);
|
|
lodepng_free(hash->headz);
|
|
lodepng_free(hash->chainz);
|
|
}
|
|
|
|
|
|
|
|
static unsigned getHash(const unsigned char* data, size_t size, size_t pos)
|
|
{
|
|
unsigned result = 0;
|
|
if(pos + 2 < size)
|
|
{
|
|
/*A simple shift and xor hash is used. Since the data of PNGs is dominated
|
|
by zeroes due to the filters, a better hash does not have a significant
|
|
effect on speed in traversing the chain, and causes more time spend on
|
|
calculating the hash.*/
|
|
result ^= (unsigned)(data[pos + 0] << 0u);
|
|
result ^= (unsigned)(data[pos + 1] << 4u);
|
|
result ^= (unsigned)(data[pos + 2] << 8u);
|
|
} else {
|
|
size_t amount, i;
|
|
if(pos >= size) return 0;
|
|
amount = size - pos;
|
|
for(i = 0; i != amount; ++i) result ^= (unsigned)(data[pos + i] << (i * 8u));
|
|
}
|
|
return result & HASH_BIT_MASK;
|
|
}
|
|
|
|
static unsigned countZeros(const unsigned char* data, size_t size, size_t pos)
|
|
{
|
|
const unsigned char* start = data + pos;
|
|
const unsigned char* end = start + MAX_SUPPORTED_DEFLATE_LENGTH;
|
|
if(end > data + size) end = data + size;
|
|
data = start;
|
|
while(data != end && *data == 0) ++data;
|
|
/*subtracting two addresses returned as 32-bit number (max value is MAX_SUPPORTED_DEFLATE_LENGTH)*/
|
|
return (unsigned)(data - start);
|
|
}
|
|
|
|
/*wpos = pos & (windowsize - 1)*/
|
|
static void updateHashChain(Hash* hash, size_t wpos, unsigned hashval, unsigned short numzeros)
|
|
{
|
|
hash->val[wpos] = (int)hashval;
|
|
if(hash->head[hashval] != -1) hash->chain[wpos] = hash->head[hashval];
|
|
hash->head[hashval] = wpos;
|
|
|
|
hash->zeros[wpos] = numzeros;
|
|
if(hash->headz[numzeros] != -1) hash->chainz[wpos] = hash->headz[numzeros];
|
|
hash->headz[numzeros] = wpos;
|
|
}
|
|
|
|
/*
|
|
LZ77-encode the data. Return value is error code. The input are raw bytes, the output
|
|
is in the form of unsigned integers with codes representing for example literal bytes, or
|
|
length/distance pairs.
|
|
It uses a hash table technique to let it encode faster. When doing LZ77 encoding, a
|
|
sliding window (of windowsize) is used, and all past bytes in that window can be used as
|
|
the "dictionary". A brute force search through all possible distances would be slow, and
|
|
this hash technique is one out of several ways to speed this up.
|
|
*/
|
|
static unsigned encodeLZ77(uivector* out, Hash* hash,
|
|
const unsigned char* in, size_t inpos, size_t insize, unsigned windowsize,
|
|
unsigned minmatch, unsigned nicematch, unsigned lazymatching)
|
|
{
|
|
size_t pos;
|
|
unsigned i, error = 0;
|
|
/*for large window lengths, assume the user wants no compression loss. Otherwise, max hash chain length speedup.*/
|
|
unsigned maxchainlength = windowsize >= 8192 ? windowsize : windowsize / 8;
|
|
unsigned maxlazymatch = windowsize >= 8192 ? MAX_SUPPORTED_DEFLATE_LENGTH : 64;
|
|
|
|
unsigned usezeros = 1; /*not sure if setting it to false for windowsize < 8192 is better or worse*/
|
|
unsigned numzeros = 0;
|
|
|
|
unsigned offset; /*the offset represents the distance in LZ77 terminology*/
|
|
unsigned length;
|
|
unsigned lazy = 0;
|
|
unsigned lazylength = 0, lazyoffset = 0;
|
|
unsigned hashval;
|
|
unsigned current_offset, current_length;
|
|
unsigned prev_offset;
|
|
const unsigned char *lastptr, *foreptr, *backptr;
|
|
unsigned hashpos;
|
|
|
|
if(windowsize == 0 || windowsize > 32768) return 60; /*error: windowsize smaller/larger than allowed*/
|
|
if((windowsize & (windowsize - 1)) != 0) return 90; /*error: must be power of two*/
|
|
|
|
if(nicematch > MAX_SUPPORTED_DEFLATE_LENGTH) nicematch = MAX_SUPPORTED_DEFLATE_LENGTH;
|
|
|
|
for(pos = inpos; pos < insize; ++pos)
|
|
{
|
|
size_t wpos = pos & (windowsize - 1); /*position for in 'circular' hash buffers*/
|
|
unsigned chainlength = 0;
|
|
|
|
hashval = getHash(in, insize, pos);
|
|
|
|
if(usezeros && hashval == 0)
|
|
{
|
|
if(numzeros == 0) numzeros = countZeros(in, insize, pos);
|
|
else if(pos + numzeros > insize || in[pos + numzeros - 1] != 0) --numzeros;
|
|
}
|
|
else
|
|
{
|
|
numzeros = 0;
|
|
}
|
|
|
|
updateHashChain(hash, wpos, hashval, numzeros);
|
|
|
|
/*the length and offset found for the current position*/
|
|
length = 0;
|
|
offset = 0;
|
|
|
|
hashpos = hash->chain[wpos];
|
|
|
|
lastptr = &in[insize < pos + MAX_SUPPORTED_DEFLATE_LENGTH ? insize : pos + MAX_SUPPORTED_DEFLATE_LENGTH];
|
|
|
|
/*search for the longest string*/
|
|
prev_offset = 0;
|
|
for(;;)
|
|
{
|
|
if(chainlength++ >= maxchainlength) break;
|
|
current_offset = hashpos <= wpos ? wpos - hashpos : wpos - hashpos + windowsize;
|
|
|
|
if(current_offset < prev_offset) break; /*stop when went completely around the circular buffer*/
|
|
prev_offset = current_offset;
|
|
if(current_offset > 0)
|
|
{
|
|
/*test the next characters*/
|
|
foreptr = &in[pos];
|
|
backptr = &in[pos - current_offset];
|
|
|
|
/*common case in PNGs is lots of zeros. Quickly skip over them as a speedup*/
|
|
if(numzeros >= 3)
|
|
{
|
|
unsigned skip = hash->zeros[hashpos];
|
|
if(skip > numzeros) skip = numzeros;
|
|
backptr += skip;
|
|
foreptr += skip;
|
|
}
|
|
|
|
while(foreptr != lastptr && *backptr == *foreptr) /*maximum supported length by deflate is max length*/
|
|
{
|
|
++backptr;
|
|
++foreptr;
|
|
}
|
|
current_length = (unsigned)(foreptr - &in[pos]);
|
|
|
|
if(current_length > length)
|
|
{
|
|
length = current_length; /*the longest length*/
|
|
offset = current_offset; /*the offset that is related to this longest length*/
|
|
/*jump out once a length of max length is found (speed gain). This also jumps
|
|
out if length is MAX_SUPPORTED_DEFLATE_LENGTH*/
|
|
if(current_length >= nicematch) break;
|
|
}
|
|
}
|
|
|
|
if(hashpos == hash->chain[hashpos]) break;
|
|
|
|
if(numzeros >= 3 && length > numzeros)
|
|
{
|
|
hashpos = hash->chainz[hashpos];
|
|
if(hash->zeros[hashpos] != numzeros) break;
|
|
}
|
|
else
|
|
{
|
|
hashpos = hash->chain[hashpos];
|
|
/*outdated hash value, happens if particular value was not encountered in whole last window*/
|
|
if(hash->val[hashpos] != (int)hashval) break;
|
|
}
|
|
}
|
|
|
|
if(lazymatching)
|
|
{
|
|
if(!lazy && length >= 3 && length <= maxlazymatch && length < MAX_SUPPORTED_DEFLATE_LENGTH)
|
|
{
|
|
lazy = 1;
|
|
lazylength = length;
|
|
lazyoffset = offset;
|
|
continue; /*try the next byte*/
|
|
}
|
|
if(lazy)
|
|
{
|
|
lazy = 0;
|
|
if(pos == 0) ERROR_BREAK(81);
|
|
if(length > lazylength + 1)
|
|
{
|
|
/*push the previous character as literal*/
|
|
if(!uivector_push_back(out, in[pos - 1])) ERROR_BREAK(83 /*alloc fail*/);
|
|
}
|
|
else
|
|
{
|
|
length = lazylength;
|
|
offset = lazyoffset;
|
|
hash->head[hashval] = -1; /*the same hashchain update will be done, this ensures no wrong alteration*/
|
|
hash->headz[numzeros] = -1; /*idem*/
|
|
--pos;
|
|
}
|
|
}
|
|
}
|
|
if(length >= 3 && offset > windowsize) ERROR_BREAK(86 /*too big (or overflown negative) offset*/);
|
|
|
|
/*encode it as length/distance pair or literal value*/
|
|
if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/
|
|
{
|
|
if(!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/);
|
|
}
|
|
else if(length < minmatch || (length == 3 && offset > 4096))
|
|
{
|
|
/*compensate for the fact that longer offsets have more extra bits, a
|
|
length of only 3 may be not worth it then*/
|
|
if(!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/);
|
|
}
|
|
else
|
|
{
|
|
addLengthDistance(out, length, offset);
|
|
for(i = 1; i < length; ++i)
|
|
{
|
|
++pos;
|
|
wpos = pos & (windowsize - 1);
|
|
hashval = getHash(in, insize, pos);
|
|
if(usezeros && hashval == 0)
|
|
{
|
|
if(numzeros == 0) numzeros = countZeros(in, insize, pos);
|
|
else if(pos + numzeros > insize || in[pos + numzeros - 1] != 0) --numzeros;
|
|
}
|
|
else
|
|
{
|
|
numzeros = 0;
|
|
}
|
|
updateHashChain(hash, wpos, hashval, numzeros);
|
|
}
|
|
}
|
|
} /*end of the loop through each character of input*/
|
|
|
|
return error;
|
|
}
|
|
|
|
/* /////////////////////////////////////////////////////////////////////////// */
|
|
|
|
static unsigned deflateNoCompression(ucvector* out, const unsigned char* data, size_t datasize)
|
|
{
|
|
/*non compressed deflate block data: 1 bit BFINAL,2 bits BTYPE,(5 bits): it jumps to start of next byte,
|
|
2 bytes LEN, 2 bytes NLEN, LEN bytes literal DATA*/
|
|
|
|
size_t i, j, numdeflateblocks = (datasize + 65534) / 65535;
|
|
unsigned datapos = 0;
|
|
for(i = 0; i != numdeflateblocks; ++i)
|
|
{
|
|
unsigned BFINAL, BTYPE, LEN, NLEN;
|
|
unsigned char firstbyte;
|
|
|
|
BFINAL = (i == numdeflateblocks - 1);
|
|
BTYPE = 0;
|
|
|
|
firstbyte = (unsigned char)(BFINAL + ((BTYPE & 1) << 1) + ((BTYPE & 2) << 1));
|
|
ucvector_push_back(out, firstbyte);
|
|
|
|
LEN = 65535;
|
|
if(datasize - datapos < 65535) LEN = (unsigned)datasize - datapos;
|
|
NLEN = 65535 - LEN;
|
|
|
|
ucvector_push_back(out, (unsigned char)(LEN % 256));
|
|
ucvector_push_back(out, (unsigned char)(LEN / 256));
|
|
ucvector_push_back(out, (unsigned char)(NLEN % 256));
|
|
ucvector_push_back(out, (unsigned char)(NLEN / 256));
|
|
|
|
/*Decompressed data*/
|
|
for(j = 0; j < 65535 && datapos < datasize; ++j)
|
|
{
|
|
ucvector_push_back(out, data[datapos++]);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
write the lz77-encoded data, which has lit, len and dist codes, to compressed stream using huffman trees.
|
|
tree_ll: the tree for lit and len codes.
|
|
tree_d: the tree for distance codes.
|
|
*/
|
|
static void writeLZ77data(size_t* bp, ucvector* out, const uivector* lz77_encoded,
|
|
const HuffmanTree* tree_ll, const HuffmanTree* tree_d)
|
|
{
|
|
size_t i = 0;
|
|
for(i = 0; i != lz77_encoded->size; ++i)
|
|
{
|
|
unsigned val = lz77_encoded->data[i];
|
|
addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_ll, val), HuffmanTree_getLength(tree_ll, val));
|
|
if(val > 256) /*for a length code, 3 more things have to be added*/
|
|
{
|
|
unsigned length_index = val - FIRST_LENGTH_CODE_INDEX;
|
|
unsigned n_length_extra_bits = LENGTHEXTRA[length_index];
|
|
unsigned length_extra_bits = lz77_encoded->data[++i];
|
|
|
|
unsigned distance_code = lz77_encoded->data[++i];
|
|
|
|
unsigned distance_index = distance_code;
|
|
unsigned n_distance_extra_bits = DISTANCEEXTRA[distance_index];
|
|
unsigned distance_extra_bits = lz77_encoded->data[++i];
|
|
|
|
addBitsToStream(bp, out, length_extra_bits, n_length_extra_bits);
|
|
addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_d, distance_code),
|
|
HuffmanTree_getLength(tree_d, distance_code));
|
|
addBitsToStream(bp, out, distance_extra_bits, n_distance_extra_bits);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*Deflate for a block of type "dynamic", that is, with freely, optimally, created huffman trees*/
|
|
static unsigned deflateDynamic(ucvector* out, size_t* bp, Hash* hash,
|
|
const unsigned char* data, size_t datapos, size_t dataend,
|
|
const LodePNGCompressSettings* settings, unsigned final)
|
|
{
|
|
unsigned error = 0;
|
|
|
|
/*
|
|
A block is compressed as follows: The PNG data is lz77 encoded, resulting in
|
|
literal bytes and length/distance pairs. This is then huffman compressed with
|
|
two huffman trees. One huffman tree is used for the lit and len values ("ll"),
|
|
another huffman tree is used for the dist values ("d"). These two trees are
|
|
stored using their code lengths, and to compress even more these code lengths
|
|
are also run-length encoded and huffman compressed. This gives a huffman tree
|
|
of code lengths "cl". The code lenghts used to describe this third tree are
|
|
the code length code lengths ("clcl").
|
|
*/
|
|
|
|
/*The lz77 encoded data, represented with integers since there will also be length and distance codes in it*/
|
|
uivector lz77_encoded;
|
|
HuffmanTree tree_ll; /*tree for lit,len values*/
|
|
HuffmanTree tree_d; /*tree for distance codes*/
|
|
HuffmanTree tree_cl; /*tree for encoding the code lengths representing tree_ll and tree_d*/
|
|
uivector frequencies_ll; /*frequency of lit,len codes*/
|
|
uivector frequencies_d; /*frequency of dist codes*/
|
|
uivector frequencies_cl; /*frequency of code length codes*/
|
|
uivector bitlen_lld; /*lit,len,dist code lenghts (int bits), literally (without repeat codes).*/
|
|
uivector bitlen_lld_e; /*bitlen_lld encoded with repeat codes (this is a rudemtary run length compression)*/
|
|
/*bitlen_cl is the code length code lengths ("clcl"). The bit lengths of codes to represent tree_cl
|
|
(these are written as is in the file, it would be crazy to compress these using yet another huffman
|
|
tree that needs to be represented by yet another set of code lengths)*/
|
|
uivector bitlen_cl;
|
|
size_t datasize = dataend - datapos;
|
|
|
|
/*
|
|
Due to the huffman compression of huffman tree representations ("two levels"), there are some anologies:
|
|
bitlen_lld is to tree_cl what data is to tree_ll and tree_d.
|
|
bitlen_lld_e is to bitlen_lld what lz77_encoded is to data.
|
|
bitlen_cl is to bitlen_lld_e what bitlen_lld is to lz77_encoded.
|
|
*/
|
|
|
|
unsigned BFINAL = final;
|
|
size_t numcodes_ll, numcodes_d, i;
|
|
unsigned HLIT, HDIST, HCLEN;
|
|
|
|
uivector_init(&lz77_encoded);
|
|
HuffmanTree_init(&tree_ll);
|
|
HuffmanTree_init(&tree_d);
|
|
HuffmanTree_init(&tree_cl);
|
|
uivector_init(&frequencies_ll);
|
|
uivector_init(&frequencies_d);
|
|
uivector_init(&frequencies_cl);
|
|
uivector_init(&bitlen_lld);
|
|
uivector_init(&bitlen_lld_e);
|
|
uivector_init(&bitlen_cl);
|
|
|
|
/*This while loop never loops due to a break at the end, it is here to
|
|
allow breaking out of it to the cleanup phase on error conditions.*/
|
|
while(!error)
|
|
{
|
|
if(settings->use_lz77)
|
|
{
|
|
error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize,
|
|
settings->minmatch, settings->nicematch, settings->lazymatching);
|
|
if(error) break;
|
|
}
|
|
else
|
|
{
|
|
if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(83 /*alloc fail*/);
|
|
for(i = datapos; i < dataend; ++i) lz77_encoded.data[i] = data[i]; /*no LZ77, but still will be Huffman compressed*/
|
|
}
|
|
|
|
if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(83 /*alloc fail*/);
|
|
if(!uivector_resizev(&frequencies_d, 30, 0)) ERROR_BREAK(83 /*alloc fail*/);
|
|
|
|
/*Count the frequencies of lit, len and dist codes*/
|
|
for(i = 0; i != lz77_encoded.size; ++i)
|
|
{
|
|
unsigned symbol = lz77_encoded.data[i];
|
|
++frequencies_ll.data[symbol];
|
|
if(symbol > 256)
|
|
{
|
|
unsigned dist = lz77_encoded.data[i + 2];
|
|
++frequencies_d.data[dist];
|
|
i += 3;
|
|
}
|
|
}
|
|
frequencies_ll.data[256] = 1; /*there will be exactly 1 end code, at the end of the block*/
|
|
|
|
/*Make both huffman trees, one for the lit and len codes, one for the dist codes*/
|
|
error = HuffmanTree_makeFromFrequencies(&tree_ll, frequencies_ll.data, 257, frequencies_ll.size, 15);
|
|
if(error) break;
|
|
/*2, not 1, is chosen for mincodes: some buggy PNG decoders require at least 2 symbols in the dist tree*/
|
|
error = HuffmanTree_makeFromFrequencies(&tree_d, frequencies_d.data, 2, frequencies_d.size, 15);
|
|
if(error) break;
|
|
|
|
numcodes_ll = tree_ll.numcodes; if(numcodes_ll > 286) numcodes_ll = 286;
|
|
numcodes_d = tree_d.numcodes; if(numcodes_d > 30) numcodes_d = 30;
|
|
/*store the code lengths of both generated trees in bitlen_lld*/
|
|
for(i = 0; i != numcodes_ll; ++i) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_ll, (unsigned)i));
|
|
for(i = 0; i != numcodes_d; ++i) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_d, (unsigned)i));
|
|
|
|
/*run-length compress bitlen_ldd into bitlen_lld_e by using repeat codes 16 (copy length 3-6 times),
|
|
17 (3-10 zeroes), 18 (11-138 zeroes)*/
|
|
for(i = 0; i != (unsigned)bitlen_lld.size; ++i)
|
|
{
|
|
unsigned j = 0; /*amount of repititions*/
|
|
while(i + j + 1 < (unsigned)bitlen_lld.size && bitlen_lld.data[i + j + 1] == bitlen_lld.data[i]) ++j;
|
|
|
|
if(bitlen_lld.data[i] == 0 && j >= 2) /*repeat code for zeroes*/
|
|
{
|
|
++j; /*include the first zero*/
|
|
if(j <= 10) /*repeat code 17 supports max 10 zeroes*/
|
|
{
|
|
uivector_push_back(&bitlen_lld_e, 17);
|
|
uivector_push_back(&bitlen_lld_e, j - 3);
|
|
}
|
|
else /*repeat code 18 supports max 138 zeroes*/
|
|
{
|
|
if(j > 138) j = 138;
|
|
uivector_push_back(&bitlen_lld_e, 18);
|
|
uivector_push_back(&bitlen_lld_e, j - 11);
|
|
}
|
|
i += (j - 1);
|
|
}
|
|
else if(j >= 3) /*repeat code for value other than zero*/
|
|
{
|
|
size_t k;
|
|
unsigned num = j / 6, rest = j % 6;
|
|
uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]);
|
|
for(k = 0; k < num; ++k)
|
|
{
|
|
uivector_push_back(&bitlen_lld_e, 16);
|
|
uivector_push_back(&bitlen_lld_e, 6 - 3);
|
|
}
|
|
if(rest >= 3)
|
|
{
|
|
uivector_push_back(&bitlen_lld_e, 16);
|
|
uivector_push_back(&bitlen_lld_e, rest - 3);
|
|
}
|
|
else j -= rest;
|
|
i += j;
|
|
}
|
|
else /*too short to benefit from repeat code*/
|
|
{
|
|
uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]);
|
|
}
|
|
}
|
|
|
|
/*generate tree_cl, the huffmantree of huffmantrees*/
|
|
|
|
if(!uivector_resizev(&frequencies_cl, NUM_CODE_LENGTH_CODES, 0)) ERROR_BREAK(83 /*alloc fail*/);
|
|
for(i = 0; i != bitlen_lld_e.size; ++i)
|
|
{
|
|
++frequencies_cl.data[bitlen_lld_e.data[i]];
|
|
/*after a repeat code come the bits that specify the number of repetitions,
|
|
those don't need to be in the frequencies_cl calculation*/
|
|
if(bitlen_lld_e.data[i] >= 16) ++i;
|
|
}
|
|
|
|
error = HuffmanTree_makeFromFrequencies(&tree_cl, frequencies_cl.data,
|
|
frequencies_cl.size, frequencies_cl.size, 7);
|
|
if(error) break;
|
|
|
|
if(!uivector_resize(&bitlen_cl, tree_cl.numcodes)) ERROR_BREAK(83 /*alloc fail*/);
|
|
for(i = 0; i != tree_cl.numcodes; ++i)
|
|
{
|
|
/*lenghts of code length tree is in the order as specified by deflate*/
|
|
bitlen_cl.data[i] = HuffmanTree_getLength(&tree_cl, CLCL_ORDER[i]);
|
|
}
|
|
while(bitlen_cl.data[bitlen_cl.size - 1] == 0 && bitlen_cl.size > 4)
|
|
{
|
|
/*remove zeros at the end, but minimum size must be 4*/
|
|
if(!uivector_resize(&bitlen_cl, bitlen_cl.size - 1)) ERROR_BREAK(83 /*alloc fail*/);
|
|
}
|
|
if(error) break;
|
|
|
|
/*
|
|
Write everything into the output
|
|
|
|
After the BFINAL and BTYPE, the dynamic block consists out of the following:
|
|
- 5 bits HLIT, 5 bits HDIST, 4 bits HCLEN
|
|
- (HCLEN+4)*3 bits code lengths of code length alphabet
|
|
- HLIT + 257 code lenghts of lit/length alphabet (encoded using the code length
|
|
alphabet, + possible repetition codes 16, 17, 18)
|
|
- HDIST + 1 code lengths of distance alphabet (encoded using the code length
|
|
alphabet, + possible repetition codes 16, 17, 18)
|
|
- compressed data
|
|
- 256 (end code)
|
|
*/
|
|
|
|
/*Write block type*/
|
|
addBitToStream(bp, out, BFINAL);
|
|
addBitToStream(bp, out, 0); /*first bit of BTYPE "dynamic"*/
|
|
addBitToStream(bp, out, 1); /*second bit of BTYPE "dynamic"*/
|
|
|
|
/*write the HLIT, HDIST and HCLEN values*/
|
|
HLIT = (unsigned)(numcodes_ll - 257);
|
|
HDIST = (unsigned)(numcodes_d - 1);
|
|
HCLEN = (unsigned)bitlen_cl.size - 4;
|
|
/*trim zeroes for HCLEN. HLIT and HDIST were already trimmed at tree creation*/
|
|
while(!bitlen_cl.data[HCLEN + 4 - 1] && HCLEN > 0) --HCLEN;
|
|
addBitsToStream(bp, out, HLIT, 5);
|
|
addBitsToStream(bp, out, HDIST, 5);
|
|
addBitsToStream(bp, out, HCLEN, 4);
|
|
|
|
/*write the code lenghts of the code length alphabet*/
|
|
for(i = 0; i != HCLEN + 4; ++i) addBitsToStream(bp, out, bitlen_cl.data[i], 3);
|
|
|
|
/*write the lenghts of the lit/len AND the dist alphabet*/
|
|
for(i = 0; i != bitlen_lld_e.size; ++i)
|
|
{
|
|
addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_cl, bitlen_lld_e.data[i]),
|
|
HuffmanTree_getLength(&tree_cl, bitlen_lld_e.data[i]));
|
|
/*extra bits of repeat codes*/
|
|
if(bitlen_lld_e.data[i] == 16) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 2);
|
|
else if(bitlen_lld_e.data[i] == 17) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 3);
|
|
else if(bitlen_lld_e.data[i] == 18) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 7);
|
|
}
|
|
|
|
/*write the compressed data symbols*/
|
|
writeLZ77data(bp, out, &lz77_encoded, &tree_ll, &tree_d);
|
|
/*error: the length of the end code 256 must be larger than 0*/
|
|
if(HuffmanTree_getLength(&tree_ll, 256) == 0) ERROR_BREAK(64);
|
|
|
|
/*write the end code*/
|
|
addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256));
|
|
|
|
break; /*end of error-while*/
|
|
}
|
|
|
|
/*cleanup*/
|
|
uivector_cleanup(&lz77_encoded);
|
|
HuffmanTree_cleanup(&tree_ll);
|
|
HuffmanTree_cleanup(&tree_d);
|
|
HuffmanTree_cleanup(&tree_cl);
|
|
uivector_cleanup(&frequencies_ll);
|
|
uivector_cleanup(&frequencies_d);
|
|
uivector_cleanup(&frequencies_cl);
|
|
uivector_cleanup(&bitlen_lld_e);
|
|
uivector_cleanup(&bitlen_lld);
|
|
uivector_cleanup(&bitlen_cl);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned deflateFixed(ucvector* out, size_t* bp, Hash* hash,
|
|
const unsigned char* data,
|
|
size_t datapos, size_t dataend,
|
|
const LodePNGCompressSettings* settings, unsigned final)
|
|
{
|
|
HuffmanTree tree_ll; /*tree for literal values and length codes*/
|
|
HuffmanTree tree_d; /*tree for distance codes*/
|
|
|
|
unsigned BFINAL = final;
|
|
unsigned error = 0;
|
|
size_t i;
|
|
|
|
HuffmanTree_init(&tree_ll);
|
|
HuffmanTree_init(&tree_d);
|
|
|
|
generateFixedLitLenTree(&tree_ll);
|
|
generateFixedDistanceTree(&tree_d);
|
|
|
|
addBitToStream(bp, out, BFINAL);
|
|
addBitToStream(bp, out, 1); /*first bit of BTYPE*/
|
|
addBitToStream(bp, out, 0); /*second bit of BTYPE*/
|
|
|
|
if(settings->use_lz77) /*LZ77 encoded*/
|
|
{
|
|
uivector lz77_encoded;
|
|
uivector_init(&lz77_encoded);
|
|
error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize,
|
|
settings->minmatch, settings->nicematch, settings->lazymatching);
|
|
if(!error) writeLZ77data(bp, out, &lz77_encoded, &tree_ll, &tree_d);
|
|
uivector_cleanup(&lz77_encoded);
|
|
}
|
|
else /*no LZ77, but still will be Huffman compressed*/
|
|
{
|
|
for(i = datapos; i < dataend; ++i)
|
|
{
|
|
addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, data[i]), HuffmanTree_getLength(&tree_ll, data[i]));
|
|
}
|
|
}
|
|
/*add END code*/
|
|
if(!error) addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256));
|
|
|
|
/*cleanup*/
|
|
HuffmanTree_cleanup(&tree_ll);
|
|
HuffmanTree_cleanup(&tree_d);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned lodepng_deflatev(ucvector* out, const unsigned char* in, size_t insize,
|
|
const LodePNGCompressSettings* settings)
|
|
{
|
|
unsigned error = 0;
|
|
size_t i, blocksize, numdeflateblocks;
|
|
size_t bp = 0; /*the bit pointer*/
|
|
Hash hash;
|
|
|
|
if(settings->btype > 2) return 61;
|
|
else if(settings->btype == 0) return deflateNoCompression(out, in, insize);
|
|
else if(settings->btype == 1) blocksize = insize;
|
|
else /*if(settings->btype == 2)*/
|
|
{
|
|
/*on PNGs, deflate blocks of 65-262k seem to give most dense encoding*/
|
|
blocksize = insize / 8 + 8;
|
|
if(blocksize < 65536) blocksize = 65536;
|
|
if(blocksize > 262144) blocksize = 262144;
|
|
}
|
|
|
|
numdeflateblocks = (insize + blocksize - 1) / blocksize;
|
|
if(numdeflateblocks == 0) numdeflateblocks = 1;
|
|
|
|
error = hash_init(&hash, settings->windowsize);
|
|
if(error) return error;
|
|
|
|
for(i = 0; i != numdeflateblocks && !error; ++i)
|
|
{
|
|
unsigned final = (i == numdeflateblocks - 1);
|
|
size_t start = i * blocksize;
|
|
size_t end = start + blocksize;
|
|
if(end > insize) end = insize;
|
|
|
|
if(settings->btype == 1) error = deflateFixed(out, &bp, &hash, in, start, end, settings, final);
|
|
else if(settings->btype == 2) error = deflateDynamic(out, &bp, &hash, in, start, end, settings, final);
|
|
}
|
|
|
|
hash_cleanup(&hash);
|
|
|
|
return error;
|
|
}
|
|
|
|
unsigned lodepng_deflate(unsigned char** out, size_t* outsize,
|
|
const unsigned char* in, size_t insize,
|
|
const LodePNGCompressSettings* settings)
|
|
{
|
|
unsigned error;
|
|
ucvector v;
|
|
ucvector_init_buffer(&v, *out, *outsize);
|
|
error = lodepng_deflatev(&v, in, insize, settings);
|
|
*out = v.data;
|
|
*outsize = v.size;
|
|
return error;
|
|
}
|
|
|
|
static unsigned deflate(unsigned char** out, size_t* outsize,
|
|
const unsigned char* in, size_t insize,
|
|
const LodePNGCompressSettings* settings)
|
|
{
|
|
if(settings->custom_deflate)
|
|
{
|
|
return settings->custom_deflate(out, outsize, in, insize, settings);
|
|
}
|
|
else
|
|
{
|
|
return lodepng_deflate(out, outsize, in, insize, settings);
|
|
}
|
|
}
|
|
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / Adler32 */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len)
|
|
{
|
|
unsigned s1 = adler & 0xffff;
|
|
unsigned s2 = (adler >> 16) & 0xffff;
|
|
|
|
while(len > 0)
|
|
{
|
|
/*at least 5550 sums can be done before the sums overflow, saving a lot of module divisions*/
|
|
unsigned amount = len > 5550 ? 5550 : len;
|
|
len -= amount;
|
|
while(amount > 0)
|
|
{
|
|
s1 += (*data++);
|
|
s2 += s1;
|
|
--amount;
|
|
}
|
|
s1 %= 65521;
|
|
s2 %= 65521;
|
|
}
|
|
|
|
return (s2 << 16) | s1;
|
|
}
|
|
|
|
/*Return the adler32 of the bytes data[0..len-1]*/
|
|
static unsigned adler32(const unsigned char* data, unsigned len)
|
|
{
|
|
return update_adler32(1L, data, len);
|
|
}
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / Zlib / */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
|
|
unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
|
|
size_t insize, const LodePNGDecompressSettings* settings)
|
|
{
|
|
unsigned error = 0;
|
|
unsigned CM, CINFO, FDICT;
|
|
|
|
if(insize < 2) return 53; /*error, size of zlib data too small*/
|
|
/*read information from zlib header*/
|
|
if((in[0] * 256 + in[1]) % 31 != 0)
|
|
{
|
|
/*error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way*/
|
|
return 24;
|
|
}
|
|
|
|
CM = in[0] & 15;
|
|
CINFO = (in[0] >> 4) & 15;
|
|
/*FCHECK = in[1] & 31;*/ /*FCHECK is already tested above*/
|
|
FDICT = (in[1] >> 5) & 1;
|
|
/*FLEVEL = (in[1] >> 6) & 3;*/ /*FLEVEL is not used here*/
|
|
|
|
if(CM != 8 || CINFO > 7)
|
|
{
|
|
/*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spec*/
|
|
return 25;
|
|
}
|
|
if(FDICT != 0)
|
|
{
|
|
/*error: the specification of PNG says about the zlib stream:
|
|
"The additional flags shall not specify a preset dictionary."*/
|
|
return 26;
|
|
}
|
|
|
|
error = inflate(out, outsize, in + 2, insize - 2, settings);
|
|
if(error) return error;
|
|
|
|
if(!settings->ignore_adler32)
|
|
{
|
|
unsigned ADLER32 = lodepng_read32bitInt(&in[insize - 4]);
|
|
unsigned checksum = adler32(*out, (unsigned)(*outsize));
|
|
if(checksum != ADLER32) return 58; /*error, adler checksum not correct, data must be corrupted*/
|
|
}
|
|
|
|
return 0; /*no error*/
|
|
}
|
|
|
|
static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
|
|
size_t insize, const LodePNGDecompressSettings* settings)
|
|
{
|
|
if(settings->custom_zlib)
|
|
{
|
|
return settings->custom_zlib(out, outsize, in, insize, settings);
|
|
}
|
|
else
|
|
{
|
|
return lodepng_zlib_decompress(out, outsize, in, insize, settings);
|
|
}
|
|
}
|
|
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
|
|
unsigned lodepng_zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
|
|
size_t insize, const LodePNGCompressSettings* settings)
|
|
{
|
|
/*initially, *out must be NULL and outsize 0, if you just give some random *out
|
|
that's pointing to a non allocated buffer, this'll crash*/
|
|
ucvector outv;
|
|
size_t i;
|
|
unsigned error;
|
|
unsigned char* deflatedata = 0;
|
|
size_t deflatesize = 0;
|
|
|
|
/*zlib data: 1 byte CMF (CM+CINFO), 1 byte FLG, deflate data, 4 byte ADLER32 checksum of the Decompressed data*/
|
|
unsigned CMF = 120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be used.*/
|
|
unsigned FLEVEL = 0;
|
|
unsigned FDICT = 0;
|
|
unsigned CMFFLG = 256 * CMF + FDICT * 32 + FLEVEL * 64;
|
|
unsigned FCHECK = 31 - CMFFLG % 31;
|
|
CMFFLG += FCHECK;
|
|
|
|
/*ucvector-controlled version of the output buffer, for dynamic array*/
|
|
ucvector_init_buffer(&outv, *out, *outsize);
|
|
|
|
ucvector_push_back(&outv, (unsigned char)(CMFFLG / 256));
|
|
ucvector_push_back(&outv, (unsigned char)(CMFFLG % 256));
|
|
|
|
error = deflate(&deflatedata, &deflatesize, in, insize, settings);
|
|
|
|
if(!error)
|
|
{
|
|
unsigned ADLER32 = adler32(in, (unsigned)insize);
|
|
for(i = 0; i != deflatesize; ++i) ucvector_push_back(&outv, deflatedata[i]);
|
|
lodepng_free(deflatedata);
|
|
lodepng_add32bitInt(&outv, ADLER32);
|
|
}
|
|
|
|
*out = outv.data;
|
|
*outsize = outv.size;
|
|
|
|
return error;
|
|
}
|
|
|
|
/* compress using the default or custom zlib function */
|
|
static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
|
|
size_t insize, const LodePNGCompressSettings* settings)
|
|
{
|
|
if(settings->custom_zlib)
|
|
{
|
|
return settings->custom_zlib(out, outsize, in, insize, settings);
|
|
}
|
|
else
|
|
{
|
|
return lodepng_zlib_compress(out, outsize, in, insize, settings);
|
|
}
|
|
}
|
|
|
|
#endif /*LODEPNG_COMPILE_ENCODER*/
|
|
|
|
#else /*no LODEPNG_COMPILE_ZLIB*/
|
|
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
|
|
size_t insize, const LodePNGDecompressSettings* settings)
|
|
{
|
|
if(!settings->custom_zlib) return 87; /*no custom zlib function provided */
|
|
return settings->custom_zlib(out, outsize, in, insize, settings);
|
|
}
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
|
|
size_t insize, const LodePNGCompressSettings* settings)
|
|
{
|
|
if(!settings->custom_zlib) return 87; /*no custom zlib function provided */
|
|
return settings->custom_zlib(out, outsize, in, insize, settings);
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ENCODER*/
|
|
|
|
#endif /*LODEPNG_COMPILE_ZLIB*/
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
|
|
/*this is a good tradeoff between speed and compression ratio*/
|
|
#define DEFAULT_WINDOWSIZE 2048
|
|
|
|
void lodepng_compress_settings_init(LodePNGCompressSettings* settings)
|
|
{
|
|
/*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/
|
|
settings->btype = 2;
|
|
settings->use_lz77 = 1;
|
|
settings->windowsize = DEFAULT_WINDOWSIZE;
|
|
settings->minmatch = 3;
|
|
settings->nicematch = 128;
|
|
settings->lazymatching = 1;
|
|
|
|
settings->custom_zlib = 0;
|
|
settings->custom_deflate = 0;
|
|
settings->custom_context = 0;
|
|
}
|
|
|
|
const LodePNGCompressSettings lodepng_default_compress_settings = {2, 1, DEFAULT_WINDOWSIZE, 3, 128, 1, 0, 0, 0};
|
|
|
|
|
|
#endif /*LODEPNG_COMPILE_ENCODER*/
|
|
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
|
|
void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings)
|
|
{
|
|
settings->ignore_adler32 = 0;
|
|
|
|
settings->custom_zlib = 0;
|
|
settings->custom_inflate = 0;
|
|
settings->custom_context = 0;
|
|
}
|
|
|
|
const LodePNGDecompressSettings lodepng_default_decompress_settings = {0, 0, 0, 0};
|
|
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* // End of Zlib related code. Begin of PNG related code. // */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
#ifdef LODEPNG_COMPILE_PNG
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / CRC32 / */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
/* CRC polynomial: 0xedb88320 */
|
|
static unsigned lodepng_crc32_table[256] = {
|
|
0u, 1996959894u, 3993919788u, 2567524794u, 124634137u, 1886057615u, 3915621685u, 2657392035u,
|
|
249268274u, 2044508324u, 3772115230u, 2547177864u, 162941995u, 2125561021u, 3887607047u, 2428444049u,
|
|
498536548u, 1789927666u, 4089016648u, 2227061214u, 450548861u, 1843258603u, 4107580753u, 2211677639u,
|
|
325883990u, 1684777152u, 4251122042u, 2321926636u, 335633487u, 1661365465u, 4195302755u, 2366115317u,
|
|
997073096u, 1281953886u, 3579855332u, 2724688242u, 1006888145u, 1258607687u, 3524101629u, 2768942443u,
|
|
901097722u, 1119000684u, 3686517206u, 2898065728u, 853044451u, 1172266101u, 3705015759u, 2882616665u,
|
|
651767980u, 1373503546u, 3369554304u, 3218104598u, 565507253u, 1454621731u, 3485111705u, 3099436303u,
|
|
671266974u, 1594198024u, 3322730930u, 2970347812u, 795835527u, 1483230225u, 3244367275u, 3060149565u,
|
|
1994146192u, 31158534u, 2563907772u, 4023717930u, 1907459465u, 112637215u, 2680153253u, 3904427059u,
|
|
2013776290u, 251722036u, 2517215374u, 3775830040u, 2137656763u, 141376813u, 2439277719u, 3865271297u,
|
|
1802195444u, 476864866u, 2238001368u, 4066508878u, 1812370925u, 453092731u, 2181625025u, 4111451223u,
|
|
1706088902u, 314042704u, 2344532202u, 4240017532u, 1658658271u, 366619977u, 2362670323u, 4224994405u,
|
|
1303535960u, 984961486u, 2747007092u, 3569037538u, 1256170817u, 1037604311u, 2765210733u, 3554079995u,
|
|
1131014506u, 879679996u, 2909243462u, 3663771856u, 1141124467u, 855842277u, 2852801631u, 3708648649u,
|
|
1342533948u, 654459306u, 3188396048u, 3373015174u, 1466479909u, 544179635u, 3110523913u, 3462522015u,
|
|
1591671054u, 702138776u, 2966460450u, 3352799412u, 1504918807u, 783551873u, 3082640443u, 3233442989u,
|
|
3988292384u, 2596254646u, 62317068u, 1957810842u, 3939845945u, 2647816111u, 81470997u, 1943803523u,
|
|
3814918930u, 2489596804u, 225274430u, 2053790376u, 3826175755u, 2466906013u, 167816743u, 2097651377u,
|
|
4027552580u, 2265490386u, 503444072u, 1762050814u, 4150417245u, 2154129355u, 426522225u, 1852507879u,
|
|
4275313526u, 2312317920u, 282753626u, 1742555852u, 4189708143u, 2394877945u, 397917763u, 1622183637u,
|
|
3604390888u, 2714866558u, 953729732u, 1340076626u, 3518719985u, 2797360999u, 1068828381u, 1219638859u,
|
|
3624741850u, 2936675148u, 906185462u, 1090812512u, 3747672003u, 2825379669u, 829329135u, 1181335161u,
|
|
3412177804u, 3160834842u, 628085408u, 1382605366u, 3423369109u, 3138078467u, 570562233u, 1426400815u,
|
|
3317316542u, 2998733608u, 733239954u, 1555261956u, 3268935591u, 3050360625u, 752459403u, 1541320221u,
|
|
2607071920u, 3965973030u, 1969922972u, 40735498u, 2617837225u, 3943577151u, 1913087877u, 83908371u,
|
|
2512341634u, 3803740692u, 2075208622u, 213261112u, 2463272603u, 3855990285u, 2094854071u, 198958881u,
|
|
2262029012u, 4057260610u, 1759359992u, 534414190u, 2176718541u, 4139329115u, 1873836001u, 414664567u,
|
|
2282248934u, 4279200368u, 1711684554u, 285281116u, 2405801727u, 4167216745u, 1634467795u, 376229701u,
|
|
2685067896u, 3608007406u, 1308918612u, 956543938u, 2808555105u, 3495958263u, 1231636301u, 1047427035u,
|
|
2932959818u, 3654703836u, 1088359270u, 936918000u, 2847714899u, 3736837829u, 1202900863u, 817233897u,
|
|
3183342108u, 3401237130u, 1404277552u, 615818150u, 3134207493u, 3453421203u, 1423857449u, 601450431u,
|
|
3009837614u, 3294710456u, 1567103746u, 711928724u, 3020668471u, 3272380065u, 1510334235u, 755167117u
|
|
};
|
|
|
|
/*Return the CRC of the bytes buf[0..len-1].*/
|
|
unsigned lodepng_crc32(const unsigned char* buf, size_t len)
|
|
{
|
|
unsigned c = 0xffffffffL;
|
|
size_t n;
|
|
|
|
for(n = 0; n < len; ++n)
|
|
{
|
|
c = lodepng_crc32_table[(c ^ buf[n]) & 0xff] ^ (c >> 8);
|
|
}
|
|
return c ^ 0xffffffffL;
|
|
}
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / Reading and writing single bits and bytes from/to stream for LodePNG / */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
static unsigned char readBitFromReversedStream(size_t* bitpointer, const unsigned char* bitstream)
|
|
{
|
|
unsigned char result = (unsigned char)((bitstream[(*bitpointer) >> 3] >> (7 - ((*bitpointer) & 0x7))) & 1);
|
|
++(*bitpointer);
|
|
return result;
|
|
}
|
|
|
|
static unsigned readBitsFromReversedStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits)
|
|
{
|
|
unsigned result = 0;
|
|
size_t i;
|
|
for(i = nbits - 1; i < nbits; --i)
|
|
{
|
|
result += (unsigned)readBitFromReversedStream(bitpointer, bitstream) << i;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
static void setBitOfReversedStream0(size_t* bitpointer, unsigned char* bitstream, unsigned char bit)
|
|
{
|
|
/*the current bit in bitstream must be 0 for this to work*/
|
|
if(bit)
|
|
{
|
|
/*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/
|
|
bitstream[(*bitpointer) >> 3] |= (bit << (7 - ((*bitpointer) & 0x7)));
|
|
}
|
|
++(*bitpointer);
|
|
}
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
|
|
static void setBitOfReversedStream(size_t* bitpointer, unsigned char* bitstream, unsigned char bit)
|
|
{
|
|
/*the current bit in bitstream may be 0 or 1 for this to work*/
|
|
if(bit == 0) bitstream[(*bitpointer) >> 3] &= (unsigned char)(~(1 << (7 - ((*bitpointer) & 0x7))));
|
|
else bitstream[(*bitpointer) >> 3] |= (1 << (7 - ((*bitpointer) & 0x7)));
|
|
++(*bitpointer);
|
|
}
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / PNG chunks / */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
unsigned lodepng_chunk_length(const unsigned char* chunk)
|
|
{
|
|
return lodepng_read32bitInt(&chunk[0]);
|
|
}
|
|
|
|
void lodepng_chunk_type(char type[5], const unsigned char* chunk)
|
|
{
|
|
unsigned i;
|
|
for(i = 0; i != 4; ++i) type[i] = (char)chunk[4 + i];
|
|
type[4] = 0; /*null termination char*/
|
|
}
|
|
|
|
unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type)
|
|
{
|
|
if(strlen(type) != 4) return 0;
|
|
return (chunk[4] == type[0] && chunk[5] == type[1] && chunk[6] == type[2] && chunk[7] == type[3]);
|
|
}
|
|
|
|
unsigned char lodepng_chunk_ancillary(const unsigned char* chunk)
|
|
{
|
|
return((chunk[4] & 32) != 0);
|
|
}
|
|
|
|
unsigned char lodepng_chunk_private(const unsigned char* chunk)
|
|
{
|
|
return((chunk[6] & 32) != 0);
|
|
}
|
|
|
|
unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk)
|
|
{
|
|
return((chunk[7] & 32) != 0);
|
|
}
|
|
|
|
unsigned char* lodepng_chunk_data(unsigned char* chunk)
|
|
{
|
|
return &chunk[8];
|
|
}
|
|
|
|
const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk)
|
|
{
|
|
return &chunk[8];
|
|
}
|
|
|
|
unsigned lodepng_chunk_check_crc(const unsigned char* chunk)
|
|
{
|
|
unsigned length = lodepng_chunk_length(chunk);
|
|
unsigned CRC = lodepng_read32bitInt(&chunk[length + 8]);
|
|
/*the CRC is taken of the data and the 4 chunk type letters, not the length*/
|
|
unsigned checksum = lodepng_crc32(&chunk[4], length + 4);
|
|
if(CRC != checksum) return 1;
|
|
else return 0;
|
|
}
|
|
|
|
void lodepng_chunk_generate_crc(unsigned char* chunk)
|
|
{
|
|
unsigned length = lodepng_chunk_length(chunk);
|
|
unsigned CRC = lodepng_crc32(&chunk[4], length + 4);
|
|
lodepng_set32bitInt(chunk + 8 + length, CRC);
|
|
}
|
|
|
|
unsigned char* lodepng_chunk_next(unsigned char* chunk)
|
|
{
|
|
unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12;
|
|
return &chunk[total_chunk_length];
|
|
}
|
|
|
|
const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk)
|
|
{
|
|
unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12;
|
|
return &chunk[total_chunk_length];
|
|
}
|
|
|
|
unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk)
|
|
{
|
|
unsigned i;
|
|
unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12;
|
|
unsigned char *chunk_start, *new_buffer;
|
|
size_t new_length = (*outlength) + total_chunk_length;
|
|
if(new_length < total_chunk_length || new_length < (*outlength)) return 77; /*integer overflow happened*/
|
|
|
|
new_buffer = (unsigned char*)lodepng_realloc(*out, new_length);
|
|
if(!new_buffer) return 83; /*alloc fail*/
|
|
(*out) = new_buffer;
|
|
(*outlength) = new_length;
|
|
chunk_start = &(*out)[new_length - total_chunk_length];
|
|
|
|
for(i = 0; i != total_chunk_length; ++i) chunk_start[i] = chunk[i];
|
|
|
|
return 0;
|
|
}
|
|
|
|
unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length,
|
|
const char* type, const unsigned char* data)
|
|
{
|
|
unsigned i;
|
|
unsigned char *chunk, *new_buffer;
|
|
size_t new_length = (*outlength) + length + 12;
|
|
if(new_length < length + 12 || new_length < (*outlength)) return 77; /*integer overflow happened*/
|
|
new_buffer = (unsigned char*)lodepng_realloc(*out, new_length);
|
|
if(!new_buffer) return 83; /*alloc fail*/
|
|
(*out) = new_buffer;
|
|
(*outlength) = new_length;
|
|
chunk = &(*out)[(*outlength) - length - 12];
|
|
|
|
/*1: length*/
|
|
lodepng_set32bitInt(chunk, (unsigned)length);
|
|
|
|
/*2: chunk name (4 letters)*/
|
|
chunk[4] = (unsigned char)type[0];
|
|
chunk[5] = (unsigned char)type[1];
|
|
chunk[6] = (unsigned char)type[2];
|
|
chunk[7] = (unsigned char)type[3];
|
|
|
|
/*3: the data*/
|
|
for(i = 0; i != length; ++i) chunk[8 + i] = data[i];
|
|
|
|
/*4: CRC (of the chunkname characters and the data)*/
|
|
lodepng_chunk_generate_crc(chunk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / Color types and such / */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
/*return type is a LodePNG error code*/
|
|
static unsigned checkColorValidity(LodePNGColorType colortype, unsigned bd) /*bd = bitdepth*/
|
|
{
|
|
switch(colortype)
|
|
{
|
|
case 0: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16)) return 37; break; /*grey*/
|
|
case 2: if(!( bd == 8 || bd == 16)) return 37; break; /*RGB*/
|
|
case 3: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 )) return 37; break; /*palette*/
|
|
case 4: if(!( bd == 8 || bd == 16)) return 37; break; /*grey + alpha*/
|
|
case 6: if(!( bd == 8 || bd == 16)) return 37; break; /*RGBA*/
|
|
default: return 31;
|
|
}
|
|
return 0; /*allowed color type / bits combination*/
|
|
}
|
|
|
|
static unsigned getNumColorChannels(LodePNGColorType colortype)
|
|
{
|
|
switch(colortype)
|
|
{
|
|
case 0: return 1; /*grey*/
|
|
case 2: return 3; /*RGB*/
|
|
case 3: return 1; /*palette*/
|
|
case 4: return 2; /*grey + alpha*/
|
|
case 6: return 4; /*RGBA*/
|
|
}
|
|
return 0; /*unexisting color type*/
|
|
}
|
|
|
|
static unsigned lodepng_get_bpp_lct(LodePNGColorType colortype, unsigned bitdepth)
|
|
{
|
|
/*bits per pixel is amount of channels * bits per channel*/
|
|
return getNumColorChannels(colortype) * bitdepth;
|
|
}
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
void lodepng_color_mode_init(LodePNGColorMode* info)
|
|
{
|
|
info->key_defined = 0;
|
|
info->key_r = info->key_g = info->key_b = 0;
|
|
info->colortype = LCT_RGBA;
|
|
info->bitdepth = 8;
|
|
info->palette = 0;
|
|
info->palettesize = 0;
|
|
}
|
|
|
|
void lodepng_color_mode_cleanup(LodePNGColorMode* info)
|
|
{
|
|
lodepng_palette_clear(info);
|
|
}
|
|
|
|
unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source)
|
|
{
|
|
size_t i;
|
|
lodepng_color_mode_cleanup(dest);
|
|
*dest = *source;
|
|
if(source->palette)
|
|
{
|
|
dest->palette = (unsigned char*)lodepng_malloc(1024);
|
|
if(!dest->palette && source->palettesize) return 83; /*alloc fail*/
|
|
for(i = 0; i != source->palettesize * 4; ++i) dest->palette[i] = source->palette[i];
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int lodepng_color_mode_equal(const LodePNGColorMode* a, const LodePNGColorMode* b)
|
|
{
|
|
size_t i;
|
|
if(a->colortype != b->colortype) return 0;
|
|
if(a->bitdepth != b->bitdepth) return 0;
|
|
if(a->key_defined != b->key_defined) return 0;
|
|
if(a->key_defined)
|
|
{
|
|
if(a->key_r != b->key_r) return 0;
|
|
if(a->key_g != b->key_g) return 0;
|
|
if(a->key_b != b->key_b) return 0;
|
|
}
|
|
if(a->palettesize != b->palettesize) return 0;
|
|
for(i = 0; i != a->palettesize * 4; ++i)
|
|
{
|
|
if(a->palette[i] != b->palette[i]) return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
void lodepng_palette_clear(LodePNGColorMode* info)
|
|
{
|
|
if(info->palette) lodepng_free(info->palette);
|
|
info->palette = 0;
|
|
info->palettesize = 0;
|
|
}
|
|
|
|
unsigned lodepng_palette_add(LodePNGColorMode* info,
|
|
unsigned char r, unsigned char g, unsigned char b, unsigned char a)
|
|
{
|
|
unsigned char* data;
|
|
/*the same resize technique as C++ std::vectors is used, and here it's made so that for a palette with
|
|
the max of 256 colors, it'll have the exact alloc size*/
|
|
if(!info->palette) /*allocate palette if empty*/
|
|
{
|
|
/*room for 256 colors with 4 bytes each*/
|
|
data = (unsigned char*)lodepng_realloc(info->palette, 1024);
|
|
if(!data) return 83; /*alloc fail*/
|
|
else info->palette = data;
|
|
}
|
|
info->palette[4 * info->palettesize + 0] = r;
|
|
info->palette[4 * info->palettesize + 1] = g;
|
|
info->palette[4 * info->palettesize + 2] = b;
|
|
info->palette[4 * info->palettesize + 3] = a;
|
|
++info->palettesize;
|
|
return 0;
|
|
}
|
|
|
|
unsigned lodepng_get_bpp(const LodePNGColorMode* info)
|
|
{
|
|
/*calculate bits per pixel out of colortype and bitdepth*/
|
|
return lodepng_get_bpp_lct(info->colortype, info->bitdepth);
|
|
}
|
|
|
|
unsigned lodepng_get_channels(const LodePNGColorMode* info)
|
|
{
|
|
return getNumColorChannels(info->colortype);
|
|
}
|
|
|
|
unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info)
|
|
{
|
|
return info->colortype == LCT_GREY || info->colortype == LCT_GREY_ALPHA;
|
|
}
|
|
|
|
unsigned lodepng_is_alpha_type(const LodePNGColorMode* info)
|
|
{
|
|
return (info->colortype & 4) != 0; /*4 or 6*/
|
|
}
|
|
|
|
unsigned lodepng_is_palette_type(const LodePNGColorMode* info)
|
|
{
|
|
return info->colortype == LCT_PALETTE;
|
|
}
|
|
|
|
unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info)
|
|
{
|
|
size_t i;
|
|
for(i = 0; i != info->palettesize; ++i)
|
|
{
|
|
if(info->palette[i * 4 + 3] < 255) return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
unsigned lodepng_can_have_alpha(const LodePNGColorMode* info)
|
|
{
|
|
return info->key_defined
|
|
|| lodepng_is_alpha_type(info)
|
|
|| lodepng_has_palette_alpha(info);
|
|
}
|
|
|
|
size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color)
|
|
{
|
|
return (w * h * lodepng_get_bpp(color) + 7) / 8;
|
|
}
|
|
|
|
size_t lodepng_get_raw_size_lct(unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth)
|
|
{
|
|
return (w * h * lodepng_get_bpp_lct(colortype, bitdepth) + 7) / 8;
|
|
}
|
|
|
|
|
|
#ifdef LODEPNG_COMPILE_PNG
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
/*in an idat chunk, each scanline is a multiple of 8 bits, unlike the lodepng output buffer*/
|
|
static size_t lodepng_get_raw_size_idat(unsigned w, unsigned h, const LodePNGColorMode* color)
|
|
{
|
|
return h * ((w * lodepng_get_bpp(color) + 7) / 8);
|
|
}
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
#endif /*LODEPNG_COMPILE_PNG*/
|
|
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
|
|
static void LodePNGUnknownChunks_init(LodePNGInfo* info)
|
|
{
|
|
unsigned i;
|
|
for(i = 0; i != 3; ++i) info->unknown_chunks_data[i] = 0;
|
|
for(i = 0; i != 3; ++i) info->unknown_chunks_size[i] = 0;
|
|
}
|
|
|
|
static void LodePNGUnknownChunks_cleanup(LodePNGInfo* info)
|
|
{
|
|
unsigned i;
|
|
for(i = 0; i != 3; ++i) lodepng_free(info->unknown_chunks_data[i]);
|
|
}
|
|
|
|
static unsigned LodePNGUnknownChunks_copy(LodePNGInfo* dest, const LodePNGInfo* src)
|
|
{
|
|
unsigned i;
|
|
|
|
LodePNGUnknownChunks_cleanup(dest);
|
|
|
|
for(i = 0; i != 3; ++i)
|
|
{
|
|
size_t j;
|
|
dest->unknown_chunks_size[i] = src->unknown_chunks_size[i];
|
|
dest->unknown_chunks_data[i] = (unsigned char*)lodepng_malloc(src->unknown_chunks_size[i]);
|
|
if(!dest->unknown_chunks_data[i] && dest->unknown_chunks_size[i]) return 83; /*alloc fail*/
|
|
for(j = 0; j < src->unknown_chunks_size[i]; ++j)
|
|
{
|
|
dest->unknown_chunks_data[i][j] = src->unknown_chunks_data[i][j];
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/******************************************************************************/
|
|
|
|
static void LodePNGText_init(LodePNGInfo* info)
|
|
{
|
|
info->text_num = 0;
|
|
info->text_keys = NULL;
|
|
info->text_strings = NULL;
|
|
}
|
|
|
|
static void LodePNGText_cleanup(LodePNGInfo* info)
|
|
{
|
|
size_t i;
|
|
for(i = 0; i != info->text_num; ++i)
|
|
{
|
|
string_cleanup(&info->text_keys[i]);
|
|
string_cleanup(&info->text_strings[i]);
|
|
}
|
|
lodepng_free(info->text_keys);
|
|
lodepng_free(info->text_strings);
|
|
}
|
|
|
|
static unsigned LodePNGText_copy(LodePNGInfo* dest, const LodePNGInfo* source)
|
|
{
|
|
size_t i = 0;
|
|
dest->text_keys = 0;
|
|
dest->text_strings = 0;
|
|
dest->text_num = 0;
|
|
for(i = 0; i != source->text_num; ++i)
|
|
{
|
|
CERROR_TRY_RETURN(lodepng_add_text(dest, source->text_keys[i], source->text_strings[i]));
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void lodepng_clear_text(LodePNGInfo* info)
|
|
{
|
|
LodePNGText_cleanup(info);
|
|
}
|
|
|
|
unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str)
|
|
{
|
|
char** new_keys = (char**)(lodepng_realloc(info->text_keys, sizeof(char*) * (info->text_num + 1)));
|
|
char** new_strings = (char**)(lodepng_realloc(info->text_strings, sizeof(char*) * (info->text_num + 1)));
|
|
if(!new_keys || !new_strings)
|
|
{
|
|
lodepng_free(new_keys);
|
|
lodepng_free(new_strings);
|
|
return 83; /*alloc fail*/
|
|
}
|
|
|
|
++info->text_num;
|
|
info->text_keys = new_keys;
|
|
info->text_strings = new_strings;
|
|
|
|
string_init(&info->text_keys[info->text_num - 1]);
|
|
string_set(&info->text_keys[info->text_num - 1], key);
|
|
|
|
string_init(&info->text_strings[info->text_num - 1]);
|
|
string_set(&info->text_strings[info->text_num - 1], str);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/******************************************************************************/
|
|
|
|
static void LodePNGIText_init(LodePNGInfo* info)
|
|
{
|
|
info->itext_num = 0;
|
|
info->itext_keys = NULL;
|
|
info->itext_langtags = NULL;
|
|
info->itext_transkeys = NULL;
|
|
info->itext_strings = NULL;
|
|
}
|
|
|
|
static void LodePNGIText_cleanup(LodePNGInfo* info)
|
|
{
|
|
size_t i;
|
|
for(i = 0; i != info->itext_num; ++i)
|
|
{
|
|
string_cleanup(&info->itext_keys[i]);
|
|
string_cleanup(&info->itext_langtags[i]);
|
|
string_cleanup(&info->itext_transkeys[i]);
|
|
string_cleanup(&info->itext_strings[i]);
|
|
}
|
|
lodepng_free(info->itext_keys);
|
|
lodepng_free(info->itext_langtags);
|
|
lodepng_free(info->itext_transkeys);
|
|
lodepng_free(info->itext_strings);
|
|
}
|
|
|
|
static unsigned LodePNGIText_copy(LodePNGInfo* dest, const LodePNGInfo* source)
|
|
{
|
|
size_t i = 0;
|
|
dest->itext_keys = 0;
|
|
dest->itext_langtags = 0;
|
|
dest->itext_transkeys = 0;
|
|
dest->itext_strings = 0;
|
|
dest->itext_num = 0;
|
|
for(i = 0; i != source->itext_num; ++i)
|
|
{
|
|
CERROR_TRY_RETURN(lodepng_add_itext(dest, source->itext_keys[i], source->itext_langtags[i],
|
|
source->itext_transkeys[i], source->itext_strings[i]));
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void lodepng_clear_itext(LodePNGInfo* info)
|
|
{
|
|
LodePNGIText_cleanup(info);
|
|
}
|
|
|
|
unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag,
|
|
const char* transkey, const char* str)
|
|
{
|
|
char** new_keys = (char**)(lodepng_realloc(info->itext_keys, sizeof(char*) * (info->itext_num + 1)));
|
|
char** new_langtags = (char**)(lodepng_realloc(info->itext_langtags, sizeof(char*) * (info->itext_num + 1)));
|
|
char** new_transkeys = (char**)(lodepng_realloc(info->itext_transkeys, sizeof(char*) * (info->itext_num + 1)));
|
|
char** new_strings = (char**)(lodepng_realloc(info->itext_strings, sizeof(char*) * (info->itext_num + 1)));
|
|
if(!new_keys || !new_langtags || !new_transkeys || !new_strings)
|
|
{
|
|
lodepng_free(new_keys);
|
|
lodepng_free(new_langtags);
|
|
lodepng_free(new_transkeys);
|
|
lodepng_free(new_strings);
|
|
return 83; /*alloc fail*/
|
|
}
|
|
|
|
++info->itext_num;
|
|
info->itext_keys = new_keys;
|
|
info->itext_langtags = new_langtags;
|
|
info->itext_transkeys = new_transkeys;
|
|
info->itext_strings = new_strings;
|
|
|
|
string_init(&info->itext_keys[info->itext_num - 1]);
|
|
string_set(&info->itext_keys[info->itext_num - 1], key);
|
|
|
|
string_init(&info->itext_langtags[info->itext_num - 1]);
|
|
string_set(&info->itext_langtags[info->itext_num - 1], langtag);
|
|
|
|
string_init(&info->itext_transkeys[info->itext_num - 1]);
|
|
string_set(&info->itext_transkeys[info->itext_num - 1], transkey);
|
|
|
|
string_init(&info->itext_strings[info->itext_num - 1]);
|
|
string_set(&info->itext_strings[info->itext_num - 1], str);
|
|
|
|
return 0;
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
|
|
void lodepng_info_init(LodePNGInfo* info)
|
|
{
|
|
lodepng_color_mode_init(&info->color);
|
|
info->interlace_method = 0;
|
|
info->compression_method = 0;
|
|
info->filter_method = 0;
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
info->background_defined = 0;
|
|
info->background_r = info->background_g = info->background_b = 0;
|
|
|
|
LodePNGText_init(info);
|
|
LodePNGIText_init(info);
|
|
|
|
info->time_defined = 0;
|
|
info->phys_defined = 0;
|
|
|
|
LodePNGUnknownChunks_init(info);
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
}
|
|
|
|
void lodepng_info_cleanup(LodePNGInfo* info)
|
|
{
|
|
lodepng_color_mode_cleanup(&info->color);
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
LodePNGText_cleanup(info);
|
|
LodePNGIText_cleanup(info);
|
|
|
|
LodePNGUnknownChunks_cleanup(info);
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
}
|
|
|
|
unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source)
|
|
{
|
|
lodepng_info_cleanup(dest);
|
|
*dest = *source;
|
|
lodepng_color_mode_init(&dest->color);
|
|
CERROR_TRY_RETURN(lodepng_color_mode_copy(&dest->color, &source->color));
|
|
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
CERROR_TRY_RETURN(LodePNGText_copy(dest, source));
|
|
CERROR_TRY_RETURN(LodePNGIText_copy(dest, source));
|
|
|
|
LodePNGUnknownChunks_init(dest);
|
|
CERROR_TRY_RETURN(LodePNGUnknownChunks_copy(dest, source));
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
return 0;
|
|
}
|
|
|
|
void lodepng_info_swap(LodePNGInfo* a, LodePNGInfo* b)
|
|
{
|
|
LodePNGInfo temp = *a;
|
|
*a = *b;
|
|
*b = temp;
|
|
}
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
/*index: bitgroup index, bits: bitgroup size(1, 2 or 4), in: bitgroup value, out: octet array to add bits to*/
|
|
static void addColorBits(unsigned char* out, size_t index, unsigned bits, unsigned in)
|
|
{
|
|
unsigned m = bits == 1 ? 7 : bits == 2 ? 3 : 1; /*8 / bits - 1*/
|
|
/*p = the partial index in the byte, e.g. with 4 palettebits it is 0 for first half or 1 for second half*/
|
|
unsigned p = index & m;
|
|
in &= (1u << bits) - 1u; /*filter out any other bits of the input value*/
|
|
in = in << (bits * (m - p));
|
|
if(p == 0) out[index * bits / 8] = in;
|
|
else out[index * bits / 8] |= in;
|
|
}
|
|
|
|
typedef struct ColorTree ColorTree;
|
|
|
|
/*
|
|
One node of a color tree
|
|
This is the data structure used to count the number of unique colors and to get a palette
|
|
index for a color. It's like an octree, but because the alpha channel is used too, each
|
|
node has 16 instead of 8 children.
|
|
*/
|
|
struct ColorTree
|
|
{
|
|
ColorTree* children[16]; /*up to 16 pointers to ColorTree of next level*/
|
|
int index; /*the payload. Only has a meaningful value if this is in the last level*/
|
|
};
|
|
|
|
static void color_tree_init(ColorTree* tree)
|
|
{
|
|
int i;
|
|
for(i = 0; i != 16; ++i) tree->children[i] = 0;
|
|
tree->index = -1;
|
|
}
|
|
|
|
static void color_tree_cleanup(ColorTree* tree)
|
|
{
|
|
int i;
|
|
for(i = 0; i != 16; ++i)
|
|
{
|
|
if(tree->children[i])
|
|
{
|
|
color_tree_cleanup(tree->children[i]);
|
|
lodepng_free(tree->children[i]);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*returns -1 if color not present, its index otherwise*/
|
|
static int color_tree_get(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a)
|
|
{
|
|
int bit = 0;
|
|
for(bit = 0; bit < 8; ++bit)
|
|
{
|
|
int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1);
|
|
if(!tree->children[i]) return -1;
|
|
else tree = tree->children[i];
|
|
}
|
|
return tree ? tree->index : -1;
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
static int color_tree_has(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a)
|
|
{
|
|
return color_tree_get(tree, r, g, b, a) >= 0;
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ENCODER*/
|
|
|
|
/*color is not allowed to already exist.
|
|
Index should be >= 0 (it's signed to be compatible with using -1 for "doesn't exist")*/
|
|
static void color_tree_add(ColorTree* tree,
|
|
unsigned char r, unsigned char g, unsigned char b, unsigned char a, unsigned index)
|
|
{
|
|
int bit;
|
|
for(bit = 0; bit < 8; ++bit)
|
|
{
|
|
int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1);
|
|
if(!tree->children[i])
|
|
{
|
|
tree->children[i] = (ColorTree*)lodepng_malloc(sizeof(ColorTree));
|
|
color_tree_init(tree->children[i]);
|
|
}
|
|
tree = tree->children[i];
|
|
}
|
|
tree->index = (int)index;
|
|
}
|
|
|
|
/*put a pixel, given its RGBA color, into image of any color type*/
|
|
static unsigned rgba8ToPixel(unsigned char* out, size_t i,
|
|
const LodePNGColorMode* mode, ColorTree* tree /*for palette*/,
|
|
unsigned char r, unsigned char g, unsigned char b, unsigned char a)
|
|
{
|
|
if(mode->colortype == LCT_GREY)
|
|
{
|
|
unsigned char grey = r; /*((unsigned short)r + g + b) / 3*/;
|
|
if(mode->bitdepth == 8) out[i] = grey;
|
|
else if(mode->bitdepth == 16) out[i * 2 + 0] = out[i * 2 + 1] = grey;
|
|
else
|
|
{
|
|
/*take the most significant bits of grey*/
|
|
grey = (grey >> (8 - mode->bitdepth)) & ((1 << mode->bitdepth) - 1);
|
|
addColorBits(out, i, mode->bitdepth, grey);
|
|
}
|
|
}
|
|
else if(mode->colortype == LCT_RGB)
|
|
{
|
|
if(mode->bitdepth == 8)
|
|
{
|
|
out[i * 3 + 0] = r;
|
|
out[i * 3 + 1] = g;
|
|
out[i * 3 + 2] = b;
|
|
}
|
|
else
|
|
{
|
|
out[i * 6 + 0] = out[i * 6 + 1] = r;
|
|
out[i * 6 + 2] = out[i * 6 + 3] = g;
|
|
out[i * 6 + 4] = out[i * 6 + 5] = b;
|
|
}
|
|
}
|
|
else if(mode->colortype == LCT_PALETTE)
|
|
{
|
|
int index = color_tree_get(tree, r, g, b, a);
|
|
if(index < 0) return 82; /*color not in palette*/
|
|
if(mode->bitdepth == 8) out[i] = index;
|
|
else addColorBits(out, i, mode->bitdepth, (unsigned)index);
|
|
}
|
|
else if(mode->colortype == LCT_GREY_ALPHA)
|
|
{
|
|
unsigned char grey = r; /*((unsigned short)r + g + b) / 3*/;
|
|
if(mode->bitdepth == 8)
|
|
{
|
|
out[i * 2 + 0] = grey;
|
|
out[i * 2 + 1] = a;
|
|
}
|
|
else if(mode->bitdepth == 16)
|
|
{
|
|
out[i * 4 + 0] = out[i * 4 + 1] = grey;
|
|
out[i * 4 + 2] = out[i * 4 + 3] = a;
|
|
}
|
|
}
|
|
else if(mode->colortype == LCT_RGBA)
|
|
{
|
|
if(mode->bitdepth == 8)
|
|
{
|
|
out[i * 4 + 0] = r;
|
|
out[i * 4 + 1] = g;
|
|
out[i * 4 + 2] = b;
|
|
out[i * 4 + 3] = a;
|
|
}
|
|
else
|
|
{
|
|
out[i * 8 + 0] = out[i * 8 + 1] = r;
|
|
out[i * 8 + 2] = out[i * 8 + 3] = g;
|
|
out[i * 8 + 4] = out[i * 8 + 5] = b;
|
|
out[i * 8 + 6] = out[i * 8 + 7] = a;
|
|
}
|
|
}
|
|
|
|
return 0; /*no error*/
|
|
}
|
|
|
|
/*put a pixel, given its RGBA16 color, into image of any color 16-bitdepth type*/
|
|
static void rgba16ToPixel(unsigned char* out, size_t i,
|
|
const LodePNGColorMode* mode,
|
|
unsigned short r, unsigned short g, unsigned short b, unsigned short a)
|
|
{
|
|
if(mode->colortype == LCT_GREY)
|
|
{
|
|
unsigned short grey = r; /*((unsigned)r + g + b) / 3*/;
|
|
out[i * 2 + 0] = (grey >> 8) & 255;
|
|
out[i * 2 + 1] = grey & 255;
|
|
}
|
|
else if(mode->colortype == LCT_RGB)
|
|
{
|
|
out[i * 6 + 0] = (r >> 8) & 255;
|
|
out[i * 6 + 1] = r & 255;
|
|
out[i * 6 + 2] = (g >> 8) & 255;
|
|
out[i * 6 + 3] = g & 255;
|
|
out[i * 6 + 4] = (b >> 8) & 255;
|
|
out[i * 6 + 5] = b & 255;
|
|
}
|
|
else if(mode->colortype == LCT_GREY_ALPHA)
|
|
{
|
|
unsigned short grey = r; /*((unsigned)r + g + b) / 3*/;
|
|
out[i * 4 + 0] = (grey >> 8) & 255;
|
|
out[i * 4 + 1] = grey & 255;
|
|
out[i * 4 + 2] = (a >> 8) & 255;
|
|
out[i * 4 + 3] = a & 255;
|
|
}
|
|
else if(mode->colortype == LCT_RGBA)
|
|
{
|
|
out[i * 8 + 0] = (r >> 8) & 255;
|
|
out[i * 8 + 1] = r & 255;
|
|
out[i * 8 + 2] = (g >> 8) & 255;
|
|
out[i * 8 + 3] = g & 255;
|
|
out[i * 8 + 4] = (b >> 8) & 255;
|
|
out[i * 8 + 5] = b & 255;
|
|
out[i * 8 + 6] = (a >> 8) & 255;
|
|
out[i * 8 + 7] = a & 255;
|
|
}
|
|
}
|
|
|
|
/*Get RGBA8 color of pixel with index i (y * width + x) from the raw image with given color type.*/
|
|
static void getPixelColorRGBA8(unsigned char* r, unsigned char* g,
|
|
unsigned char* b, unsigned char* a,
|
|
const unsigned char* in, size_t i,
|
|
const LodePNGColorMode* mode)
|
|
{
|
|
if(mode->colortype == LCT_GREY)
|
|
{
|
|
if(mode->bitdepth == 8)
|
|
{
|
|
*r = *g = *b = in[i];
|
|
if(mode->key_defined && *r == mode->key_r) *a = 0;
|
|
else *a = 255;
|
|
}
|
|
else if(mode->bitdepth == 16)
|
|
{
|
|
*r = *g = *b = in[i * 2 + 0];
|
|
if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0;
|
|
else *a = 255;
|
|
}
|
|
else
|
|
{
|
|
unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/
|
|
size_t j = i * mode->bitdepth;
|
|
unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth);
|
|
*r = *g = *b = (value * 255) / highest;
|
|
if(mode->key_defined && value == mode->key_r) *a = 0;
|
|
else *a = 255;
|
|
}
|
|
}
|
|
else if(mode->colortype == LCT_RGB)
|
|
{
|
|
if(mode->bitdepth == 8)
|
|
{
|
|
*r = in[i * 3 + 0]; *g = in[i * 3 + 1]; *b = in[i * 3 + 2];
|
|
if(mode->key_defined && *r == mode->key_r && *g == mode->key_g && *b == mode->key_b) *a = 0;
|
|
else *a = 255;
|
|
}
|
|
else
|
|
{
|
|
*r = in[i * 6 + 0];
|
|
*g = in[i * 6 + 2];
|
|
*b = in[i * 6 + 4];
|
|
if(mode->key_defined && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r
|
|
&& 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g
|
|
&& 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0;
|
|
else *a = 255;
|
|
}
|
|
}
|
|
else if(mode->colortype == LCT_PALETTE)
|
|
{
|
|
unsigned index;
|
|
if(mode->bitdepth == 8) index = in[i];
|
|
else
|
|
{
|
|
size_t j = i * mode->bitdepth;
|
|
index = readBitsFromReversedStream(&j, in, mode->bitdepth);
|
|
}
|
|
|
|
if(index >= mode->palettesize)
|
|
{
|
|
/*This is an error according to the PNG spec, but common PNG decoders make it black instead.
|
|
Done here too, slightly faster due to no error handling needed.*/
|
|
*r = *g = *b = 0;
|
|
*a = 255;
|
|
}
|
|
else
|
|
{
|
|
*r = mode->palette[index * 4 + 0];
|
|
*g = mode->palette[index * 4 + 1];
|
|
*b = mode->palette[index * 4 + 2];
|
|
*a = mode->palette[index * 4 + 3];
|
|
}
|
|
}
|
|
else if(mode->colortype == LCT_GREY_ALPHA)
|
|
{
|
|
if(mode->bitdepth == 8)
|
|
{
|
|
*r = *g = *b = in[i * 2 + 0];
|
|
*a = in[i * 2 + 1];
|
|
}
|
|
else
|
|
{
|
|
*r = *g = *b = in[i * 4 + 0];
|
|
*a = in[i * 4 + 2];
|
|
}
|
|
}
|
|
else if(mode->colortype == LCT_RGBA)
|
|
{
|
|
if(mode->bitdepth == 8)
|
|
{
|
|
*r = in[i * 4 + 0];
|
|
*g = in[i * 4 + 1];
|
|
*b = in[i * 4 + 2];
|
|
*a = in[i * 4 + 3];
|
|
}
|
|
else
|
|
{
|
|
*r = in[i * 8 + 0];
|
|
*g = in[i * 8 + 2];
|
|
*b = in[i * 8 + 4];
|
|
*a = in[i * 8 + 6];
|
|
}
|
|
}
|
|
}
|
|
|
|
/*Similar to getPixelColorRGBA8, but with all the for loops inside of the color
|
|
mode test cases, optimized to convert the colors much faster, when converting
|
|
to RGBA or RGB with 8 bit per cannel. buffer must be RGBA or RGB output with
|
|
enough memory, if has_alpha is true the output is RGBA. mode has the color mode
|
|
of the input buffer.*/
|
|
static void getPixelColorsRGBA8(unsigned char* buffer, size_t numpixels,
|
|
unsigned has_alpha, const unsigned char* in,
|
|
const LodePNGColorMode* mode)
|
|
{
|
|
unsigned num_channels = has_alpha ? 4 : 3;
|
|
size_t i;
|
|
if(mode->colortype == LCT_GREY)
|
|
{
|
|
if(mode->bitdepth == 8)
|
|
{
|
|
for(i = 0; i != numpixels; ++i, buffer += num_channels)
|
|
{
|
|
buffer[0] = buffer[1] = buffer[2] = in[i];
|
|
if(has_alpha) buffer[3] = mode->key_defined && in[i] == mode->key_r ? 0 : 255;
|
|
}
|
|
}
|
|
else if(mode->bitdepth == 16)
|
|
{
|
|
for(i = 0; i != numpixels; ++i, buffer += num_channels)
|
|
{
|
|
buffer[0] = buffer[1] = buffer[2] = in[i * 2];
|
|
if(has_alpha) buffer[3] = mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r ? 0 : 255;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/
|
|
size_t j = 0;
|
|
for(i = 0; i != numpixels; ++i, buffer += num_channels)
|
|
{
|
|
unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth);
|
|
buffer[0] = buffer[1] = buffer[2] = (value * 255) / highest;
|
|
if(has_alpha) buffer[3] = mode->key_defined && value == mode->key_r ? 0 : 255;
|
|
}
|
|
}
|
|
}
|
|
else if(mode->colortype == LCT_RGB)
|
|
{
|
|
if(mode->bitdepth == 8)
|
|
{
|
|
for(i = 0; i != numpixels; ++i, buffer += num_channels)
|
|
{
|
|
buffer[0] = in[i * 3 + 0];
|
|
buffer[1] = in[i * 3 + 1];
|
|
buffer[2] = in[i * 3 + 2];
|
|
if(has_alpha) buffer[3] = mode->key_defined && buffer[0] == mode->key_r
|
|
&& buffer[1]== mode->key_g && buffer[2] == mode->key_b ? 0 : 255;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i != numpixels; ++i, buffer += num_channels)
|
|
{
|
|
buffer[0] = in[i * 6 + 0];
|
|
buffer[1] = in[i * 6 + 2];
|
|
buffer[2] = in[i * 6 + 4];
|
|
if(has_alpha) buffer[3] = mode->key_defined
|
|
&& 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r
|
|
&& 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g
|
|
&& 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b ? 0 : 255;
|
|
}
|
|
}
|
|
}
|
|
else if(mode->colortype == LCT_PALETTE)
|
|
{
|
|
unsigned index;
|
|
size_t j = 0;
|
|
for(i = 0; i != numpixels; ++i, buffer += num_channels)
|
|
{
|
|
if(mode->bitdepth == 8) index = in[i];
|
|
else index = readBitsFromReversedStream(&j, in, mode->bitdepth);
|
|
|
|
if(index >= mode->palettesize)
|
|
{
|
|
/*This is an error according to the PNG spec, but most PNG decoders make it black instead.
|
|
Done here too, slightly faster due to no error handling needed.*/
|
|
buffer[0] = buffer[1] = buffer[2] = 0;
|
|
if(has_alpha) buffer[3] = 255;
|
|
}
|
|
else
|
|
{
|
|
buffer[0] = mode->palette[index * 4 + 0];
|
|
buffer[1] = mode->palette[index * 4 + 1];
|
|
buffer[2] = mode->palette[index * 4 + 2];
|
|
if(has_alpha) buffer[3] = mode->palette[index * 4 + 3];
|
|
}
|
|
}
|
|
}
|
|
else if(mode->colortype == LCT_GREY_ALPHA)
|
|
{
|
|
if(mode->bitdepth == 8)
|
|
{
|
|
for(i = 0; i != numpixels; ++i, buffer += num_channels)
|
|
{
|
|
buffer[0] = buffer[1] = buffer[2] = in[i * 2 + 0];
|
|
if(has_alpha) buffer[3] = in[i * 2 + 1];
|
|
}
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i != numpixels; ++i, buffer += num_channels)
|
|
{
|
|
buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0];
|
|
if(has_alpha) buffer[3] = in[i * 4 + 2];
|
|
}
|
|
}
|
|
}
|
|
else if(mode->colortype == LCT_RGBA)
|
|
{
|
|
if(mode->bitdepth == 8)
|
|
{
|
|
for(i = 0; i != numpixels; ++i, buffer += num_channels)
|
|
{
|
|
buffer[0] = in[i * 4 + 0];
|
|
buffer[1] = in[i * 4 + 1];
|
|
buffer[2] = in[i * 4 + 2];
|
|
if(has_alpha) buffer[3] = in[i * 4 + 3];
|
|
}
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i != numpixels; ++i, buffer += num_channels)
|
|
{
|
|
buffer[0] = in[i * 8 + 0];
|
|
buffer[1] = in[i * 8 + 2];
|
|
buffer[2] = in[i * 8 + 4];
|
|
if(has_alpha) buffer[3] = in[i * 8 + 6];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*Get RGBA16 color of pixel with index i (y * width + x) from the raw image with
|
|
given color type, but the given color type must be 16-bit itself.*/
|
|
static void getPixelColorRGBA16(unsigned short* r, unsigned short* g, unsigned short* b, unsigned short* a,
|
|
const unsigned char* in, size_t i, const LodePNGColorMode* mode)
|
|
{
|
|
if(mode->colortype == LCT_GREY)
|
|
{
|
|
*r = *g = *b = 256 * in[i * 2 + 0] + in[i * 2 + 1];
|
|
if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0;
|
|
else *a = 65535;
|
|
}
|
|
else if(mode->colortype == LCT_RGB)
|
|
{
|
|
*r = 256 * in[i * 6 + 0] + in[i * 6 + 1];
|
|
*g = 256 * in[i * 6 + 2] + in[i * 6 + 3];
|
|
*b = 256 * in[i * 6 + 4] + in[i * 6 + 5];
|
|
if(mode->key_defined && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r
|
|
&& 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g
|
|
&& 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0;
|
|
else *a = 65535;
|
|
}
|
|
else if(mode->colortype == LCT_GREY_ALPHA)
|
|
{
|
|
*r = *g = *b = 256 * in[i * 4 + 0] + in[i * 4 + 1];
|
|
*a = 256 * in[i * 4 + 2] + in[i * 4 + 3];
|
|
}
|
|
else if(mode->colortype == LCT_RGBA)
|
|
{
|
|
*r = 256 * in[i * 8 + 0] + in[i * 8 + 1];
|
|
*g = 256 * in[i * 8 + 2] + in[i * 8 + 3];
|
|
*b = 256 * in[i * 8 + 4] + in[i * 8 + 5];
|
|
*a = 256 * in[i * 8 + 6] + in[i * 8 + 7];
|
|
}
|
|
}
|
|
|
|
unsigned lodepng_convert(unsigned char* out, const unsigned char* in,
|
|
LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in,
|
|
unsigned w, unsigned h)
|
|
{
|
|
size_t i;
|
|
ColorTree tree;
|
|
size_t numpixels = w * h;
|
|
|
|
if(lodepng_color_mode_equal(mode_out, mode_in))
|
|
{
|
|
size_t numbytes = lodepng_get_raw_size(w, h, mode_in);
|
|
for(i = 0; i != numbytes; ++i) out[i] = in[i];
|
|
return 0;
|
|
}
|
|
|
|
if(mode_out->colortype == LCT_PALETTE)
|
|
{
|
|
size_t palsize = 1u << mode_out->bitdepth;
|
|
if(mode_out->palettesize < palsize) palsize = mode_out->palettesize;
|
|
color_tree_init(&tree);
|
|
for(i = 0; i != palsize; ++i)
|
|
{
|
|
unsigned char* p = &mode_out->palette[i * 4];
|
|
color_tree_add(&tree, p[0], p[1], p[2], p[3], i);
|
|
}
|
|
}
|
|
|
|
if(mode_in->bitdepth == 16 && mode_out->bitdepth == 16)
|
|
{
|
|
for(i = 0; i != numpixels; ++i)
|
|
{
|
|
unsigned short r = 0, g = 0, b = 0, a = 0;
|
|
getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in);
|
|
rgba16ToPixel(out, i, mode_out, r, g, b, a);
|
|
}
|
|
}
|
|
else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGBA)
|
|
{
|
|
getPixelColorsRGBA8(out, numpixels, 1, in, mode_in);
|
|
}
|
|
else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGB)
|
|
{
|
|
getPixelColorsRGBA8(out, numpixels, 0, in, mode_in);
|
|
}
|
|
else
|
|
{
|
|
unsigned char r = 0, g = 0, b = 0, a = 0;
|
|
for(i = 0; i != numpixels; ++i)
|
|
{
|
|
getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in);
|
|
rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a);
|
|
}
|
|
}
|
|
|
|
if(mode_out->colortype == LCT_PALETTE)
|
|
{
|
|
color_tree_cleanup(&tree);
|
|
}
|
|
|
|
return 0; /*no error (this function currently never has one, but maybe OOM detection added later.)*/
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
|
|
void lodepng_color_profile_init(LodePNGColorProfile* profile)
|
|
{
|
|
profile->colored = 0;
|
|
profile->key = 0;
|
|
profile->alpha = 0;
|
|
profile->key_r = profile->key_g = profile->key_b = 0;
|
|
profile->numcolors = 0;
|
|
profile->bits = 1;
|
|
}
|
|
|
|
/*function used for debug purposes with C++*/
|
|
/*void printColorProfile(LodePNGColorProfile* p)
|
|
{
|
|
std::cout << "colored: " << (int)p->colored << ", ";
|
|
std::cout << "key: " << (int)p->key << ", ";
|
|
std::cout << "key_r: " << (int)p->key_r << ", ";
|
|
std::cout << "key_g: " << (int)p->key_g << ", ";
|
|
std::cout << "key_b: " << (int)p->key_b << ", ";
|
|
std::cout << "alpha: " << (int)p->alpha << ", ";
|
|
std::cout << "numcolors: " << (int)p->numcolors << ", ";
|
|
std::cout << "bits: " << (int)p->bits << std::endl;
|
|
}*/
|
|
|
|
/*Returns how many bits needed to represent given value (max 8 bit)*/
|
|
static unsigned getValueRequiredBits(unsigned char value)
|
|
{
|
|
if(value == 0 || value == 255) return 1;
|
|
/*The scaling of 2-bit and 4-bit values uses multiples of 85 and 17*/
|
|
if(value % 17 == 0) return value % 85 == 0 ? 2 : 4;
|
|
return 8;
|
|
}
|
|
|
|
/*profile must already have been inited with mode.
|
|
It's ok to set some parameters of profile to done already.*/
|
|
unsigned lodepng_get_color_profile(LodePNGColorProfile* profile,
|
|
const unsigned char* in, unsigned w, unsigned h,
|
|
const LodePNGColorMode* mode)
|
|
{
|
|
unsigned error = 0;
|
|
size_t i;
|
|
ColorTree tree;
|
|
size_t numpixels = w * h;
|
|
|
|
unsigned colored_done = lodepng_is_greyscale_type(mode) ? 1 : 0;
|
|
unsigned alpha_done = lodepng_can_have_alpha(mode) ? 0 : 1;
|
|
unsigned numcolors_done = 0;
|
|
unsigned bpp = lodepng_get_bpp(mode);
|
|
unsigned bits_done = bpp == 1 ? 1 : 0;
|
|
unsigned maxnumcolors = 257;
|
|
unsigned sixteen = 0;
|
|
if(bpp <= 8) maxnumcolors = bpp == 1 ? 2 : (bpp == 2 ? 4 : (bpp == 4 ? 16 : 256));
|
|
|
|
color_tree_init(&tree);
|
|
|
|
/*Check if the 16-bit input is truly 16-bit*/
|
|
if(mode->bitdepth == 16)
|
|
{
|
|
unsigned short r, g, b, a;
|
|
for(i = 0; i != numpixels; ++i)
|
|
{
|
|
getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode);
|
|
if((r & 255) != ((r >> 8) & 255) || (g & 255) != ((g >> 8) & 255) ||
|
|
(b & 255) != ((b >> 8) & 255) || (a & 255) != ((a >> 8) & 255)) /*first and second byte differ*/
|
|
{
|
|
sixteen = 1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if(sixteen)
|
|
{
|
|
unsigned short r = 0, g = 0, b = 0, a = 0;
|
|
profile->bits = 16;
|
|
bits_done = numcolors_done = 1; /*counting colors no longer useful, palette doesn't support 16-bit*/
|
|
|
|
for(i = 0; i != numpixels; ++i)
|
|
{
|
|
getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode);
|
|
|
|
if(!colored_done && (r != g || r != b))
|
|
{
|
|
profile->colored = 1;
|
|
colored_done = 1;
|
|
}
|
|
|
|
if(!alpha_done)
|
|
{
|
|
unsigned matchkey = (r == profile->key_r && g == profile->key_g && b == profile->key_b);
|
|
if(a != 65535 && (a != 0 || (profile->key && !matchkey)))
|
|
{
|
|
profile->alpha = 1;
|
|
alpha_done = 1;
|
|
if(profile->bits < 8) profile->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
|
|
}
|
|
else if(a == 0 && !profile->alpha && !profile->key)
|
|
{
|
|
profile->key = 1;
|
|
profile->key_r = r;
|
|
profile->key_g = g;
|
|
profile->key_b = b;
|
|
}
|
|
else if(a == 65535 && profile->key && matchkey)
|
|
{
|
|
/* Color key cannot be used if an opaque pixel also has that RGB color. */
|
|
profile->alpha = 1;
|
|
alpha_done = 1;
|
|
}
|
|
}
|
|
|
|
if(alpha_done && numcolors_done && colored_done && bits_done) break;
|
|
}
|
|
}
|
|
else /* < 16-bit */
|
|
{
|
|
for(i = 0; i != numpixels; ++i)
|
|
{
|
|
unsigned char r = 0, g = 0, b = 0, a = 0;
|
|
getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode);
|
|
|
|
if(!bits_done && profile->bits < 8)
|
|
{
|
|
/*only r is checked, < 8 bits is only relevant for greyscale*/
|
|
unsigned bits = getValueRequiredBits(r);
|
|
if(bits > profile->bits) profile->bits = bits;
|
|
}
|
|
bits_done = (profile->bits >= bpp);
|
|
|
|
if(!colored_done && (r != g || r != b))
|
|
{
|
|
profile->colored = 1;
|
|
colored_done = 1;
|
|
if(profile->bits < 8) profile->bits = 8; /*PNG has no colored modes with less than 8-bit per channel*/
|
|
}
|
|
|
|
if(!alpha_done)
|
|
{
|
|
unsigned matchkey = (r == profile->key_r && g == profile->key_g && b == profile->key_b);
|
|
if(a != 255 && (a != 0 || (profile->key && !matchkey)))
|
|
{
|
|
profile->alpha = 1;
|
|
alpha_done = 1;
|
|
if(profile->bits < 8) profile->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
|
|
}
|
|
else if(a == 0 && !profile->alpha && !profile->key)
|
|
{
|
|
profile->key = 1;
|
|
profile->key_r = r;
|
|
profile->key_g = g;
|
|
profile->key_b = b;
|
|
}
|
|
else if(a == 255 && profile->key && matchkey)
|
|
{
|
|
/* Color key cannot be used if an opaque pixel also has that RGB color. */
|
|
profile->alpha = 1;
|
|
alpha_done = 1;
|
|
if(profile->bits < 8) profile->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
|
|
}
|
|
}
|
|
|
|
if(!numcolors_done)
|
|
{
|
|
if(!color_tree_has(&tree, r, g, b, a))
|
|
{
|
|
color_tree_add(&tree, r, g, b, a, profile->numcolors);
|
|
if(profile->numcolors < 256)
|
|
{
|
|
unsigned char* p = profile->palette;
|
|
unsigned n = profile->numcolors;
|
|
p[n * 4 + 0] = r;
|
|
p[n * 4 + 1] = g;
|
|
p[n * 4 + 2] = b;
|
|
p[n * 4 + 3] = a;
|
|
}
|
|
++profile->numcolors;
|
|
numcolors_done = profile->numcolors >= maxnumcolors;
|
|
}
|
|
}
|
|
|
|
if(alpha_done && numcolors_done && colored_done && bits_done) break;
|
|
}
|
|
|
|
/*make the profile's key always 16-bit for consistency - repeat each byte twice*/
|
|
profile->key_r += (profile->key_r << 8);
|
|
profile->key_g += (profile->key_g << 8);
|
|
profile->key_b += (profile->key_b << 8);
|
|
}
|
|
|
|
color_tree_cleanup(&tree);
|
|
return error;
|
|
}
|
|
|
|
/*Automatically chooses color type that gives smallest amount of bits in the
|
|
output image, e.g. grey if there are only greyscale pixels, palette if there
|
|
are less than 256 colors, ...
|
|
Updates values of mode with a potentially smaller color model. mode_out should
|
|
contain the user chosen color model, but will be overwritten with the new chosen one.*/
|
|
unsigned lodepng_auto_choose_color(LodePNGColorMode* mode_out,
|
|
const unsigned char* image, unsigned w, unsigned h,
|
|
const LodePNGColorMode* mode_in)
|
|
{
|
|
LodePNGColorProfile prof;
|
|
unsigned error = 0;
|
|
unsigned i, n, palettebits, grey_ok, palette_ok;
|
|
|
|
lodepng_color_profile_init(&prof);
|
|
error = lodepng_get_color_profile(&prof, image, w, h, mode_in);
|
|
if(error) return error;
|
|
mode_out->key_defined = 0;
|
|
|
|
if(prof.key && w * h <= 16)
|
|
{
|
|
prof.alpha = 1; /*too few pixels to justify tRNS chunk overhead*/
|
|
if(prof.bits < 8) prof.bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
|
|
}
|
|
grey_ok = !prof.colored && !prof.alpha; /*grey without alpha, with potentially low bits*/
|
|
n = prof.numcolors;
|
|
palettebits = n <= 2 ? 1 : (n <= 4 ? 2 : (n <= 16 ? 4 : 8));
|
|
palette_ok = n <= 256 && (n * 2 < w * h) && prof.bits <= 8;
|
|
if(w * h < n * 2) palette_ok = 0; /*don't add palette overhead if image has only a few pixels*/
|
|
if(grey_ok && prof.bits <= palettebits) palette_ok = 0; /*grey is less overhead*/
|
|
|
|
if(palette_ok)
|
|
{
|
|
unsigned char* p = prof.palette;
|
|
lodepng_palette_clear(mode_out); /*remove potential earlier palette*/
|
|
for(i = 0; i != prof.numcolors; ++i)
|
|
{
|
|
error = lodepng_palette_add(mode_out, p[i * 4 + 0], p[i * 4 + 1], p[i * 4 + 2], p[i * 4 + 3]);
|
|
if(error) break;
|
|
}
|
|
|
|
mode_out->colortype = LCT_PALETTE;
|
|
mode_out->bitdepth = palettebits;
|
|
|
|
if(mode_in->colortype == LCT_PALETTE && mode_in->palettesize >= mode_out->palettesize
|
|
&& mode_in->bitdepth == mode_out->bitdepth)
|
|
{
|
|
/*If input should have same palette colors, keep original to preserve its order and prevent conversion*/
|
|
lodepng_color_mode_cleanup(mode_out);
|
|
lodepng_color_mode_copy(mode_out, mode_in);
|
|
}
|
|
}
|
|
else /*8-bit or 16-bit per channel*/
|
|
{
|
|
mode_out->bitdepth = prof.bits;
|
|
mode_out->colortype = prof.alpha ? (prof.colored ? LCT_RGBA : LCT_GREY_ALPHA)
|
|
: (prof.colored ? LCT_RGB : LCT_GREY);
|
|
|
|
if(prof.key && !prof.alpha)
|
|
{
|
|
unsigned mask = (1u << mode_out->bitdepth) - 1u; /*profile always uses 16-bit, mask converts it*/
|
|
mode_out->key_r = prof.key_r & mask;
|
|
mode_out->key_g = prof.key_g & mask;
|
|
mode_out->key_b = prof.key_b & mask;
|
|
mode_out->key_defined = 1;
|
|
}
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
#endif /* #ifdef LODEPNG_COMPILE_ENCODER */
|
|
|
|
/*
|
|
Paeth predicter, used by PNG filter type 4
|
|
The parameters are of type short, but should come from unsigned chars, the shorts
|
|
are only needed to make the paeth calculation correct.
|
|
*/
|
|
static unsigned char paethPredictor(short a, short b, short c)
|
|
{
|
|
short pa = abs(b - c);
|
|
short pb = abs(a - c);
|
|
short pc = abs(a + b - c - c);
|
|
|
|
if(pc < pa && pc < pb) return (unsigned char)c;
|
|
else if(pb < pa) return (unsigned char)b;
|
|
else return (unsigned char)a;
|
|
}
|
|
|
|
/*shared values used by multiple Adam7 related functions*/
|
|
|
|
static const unsigned ADAM7_IX[7] = { 0, 4, 0, 2, 0, 1, 0 }; /*x start values*/
|
|
static const unsigned ADAM7_IY[7] = { 0, 0, 4, 0, 2, 0, 1 }; /*y start values*/
|
|
static const unsigned ADAM7_DX[7] = { 8, 8, 4, 4, 2, 2, 1 }; /*x delta values*/
|
|
static const unsigned ADAM7_DY[7] = { 8, 8, 8, 4, 4, 2, 2 }; /*y delta values*/
|
|
|
|
/*
|
|
Outputs various dimensions and positions in the image related to the Adam7 reduced images.
|
|
passw: output containing the width of the 7 passes
|
|
passh: output containing the height of the 7 passes
|
|
filter_passstart: output containing the index of the start and end of each
|
|
reduced image with filter bytes
|
|
padded_passstart output containing the index of the start and end of each
|
|
reduced image when without filter bytes but with padded scanlines
|
|
passstart: output containing the index of the start and end of each reduced
|
|
image without padding between scanlines, but still padding between the images
|
|
w, h: width and height of non-interlaced image
|
|
bpp: bits per pixel
|
|
"padded" is only relevant if bpp is less than 8 and a scanline or image does not
|
|
end at a full byte
|
|
*/
|
|
static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t filter_passstart[8],
|
|
size_t padded_passstart[8], size_t passstart[8], unsigned w, unsigned h, unsigned bpp)
|
|
{
|
|
/*the passstart values have 8 values: the 8th one indicates the byte after the end of the 7th (= last) pass*/
|
|
unsigned i;
|
|
|
|
/*calculate width and height in pixels of each pass*/
|
|
for(i = 0; i != 7; ++i)
|
|
{
|
|
passw[i] = (w + ADAM7_DX[i] - ADAM7_IX[i] - 1) / ADAM7_DX[i];
|
|
passh[i] = (h + ADAM7_DY[i] - ADAM7_IY[i] - 1) / ADAM7_DY[i];
|
|
if(passw[i] == 0) passh[i] = 0;
|
|
if(passh[i] == 0) passw[i] = 0;
|
|
}
|
|
|
|
filter_passstart[0] = padded_passstart[0] = passstart[0] = 0;
|
|
for(i = 0; i != 7; ++i)
|
|
{
|
|
/*if passw[i] is 0, it's 0 bytes, not 1 (no filtertype-byte)*/
|
|
filter_passstart[i + 1] = filter_passstart[i]
|
|
+ ((passw[i] && passh[i]) ? passh[i] * (1 + (passw[i] * bpp + 7) / 8) : 0);
|
|
/*bits padded if needed to fill full byte at end of each scanline*/
|
|
padded_passstart[i + 1] = padded_passstart[i] + passh[i] * ((passw[i] * bpp + 7) / 8);
|
|
/*only padded at end of reduced image*/
|
|
passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7) / 8;
|
|
}
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / PNG Decoder / */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
/*read the information from the header and store it in the LodePNGInfo. return value is error*/
|
|
unsigned lodepng_inspect(unsigned* w, unsigned* h, LodePNGState* state,
|
|
const unsigned char* in, size_t insize)
|
|
{
|
|
LodePNGInfo* info = &state->info_png;
|
|
if(insize == 0 || in == 0)
|
|
{
|
|
CERROR_RETURN_ERROR(state->error, 48); /*error: the given data is empty*/
|
|
}
|
|
if(insize < 33)
|
|
{
|
|
CERROR_RETURN_ERROR(state->error, 27); /*error: the data length is smaller than the length of a PNG header*/
|
|
}
|
|
|
|
/*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/
|
|
lodepng_info_cleanup(info);
|
|
lodepng_info_init(info);
|
|
|
|
if(in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71
|
|
|| in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10)
|
|
{
|
|
CERROR_RETURN_ERROR(state->error, 28); /*error: the first 8 bytes are not the correct PNG signature*/
|
|
}
|
|
if(in[12] != 'I' || in[13] != 'H' || in[14] != 'D' || in[15] != 'R')
|
|
{
|
|
CERROR_RETURN_ERROR(state->error, 29); /*error: it doesn't start with a IHDR chunk!*/
|
|
}
|
|
|
|
/*read the values given in the header*/
|
|
*w = lodepng_read32bitInt(&in[16]);
|
|
*h = lodepng_read32bitInt(&in[20]);
|
|
info->color.bitdepth = in[24];
|
|
info->color.colortype = (LodePNGColorType)in[25];
|
|
info->compression_method = in[26];
|
|
info->filter_method = in[27];
|
|
info->interlace_method = in[28];
|
|
|
|
if(*w == 0 || *h == 0)
|
|
{
|
|
CERROR_RETURN_ERROR(state->error, 93);
|
|
}
|
|
|
|
if(!state->decoder.ignore_crc)
|
|
{
|
|
unsigned CRC = lodepng_read32bitInt(&in[29]);
|
|
unsigned checksum = lodepng_crc32(&in[12], 17);
|
|
if(CRC != checksum)
|
|
{
|
|
CERROR_RETURN_ERROR(state->error, 57); /*invalid CRC*/
|
|
}
|
|
}
|
|
|
|
/*error: only compression method 0 is allowed in the specification*/
|
|
if(info->compression_method != 0) CERROR_RETURN_ERROR(state->error, 32);
|
|
/*error: only filter method 0 is allowed in the specification*/
|
|
if(info->filter_method != 0) CERROR_RETURN_ERROR(state->error, 33);
|
|
/*error: only interlace methods 0 and 1 exist in the specification*/
|
|
if(info->interlace_method > 1) CERROR_RETURN_ERROR(state->error, 34);
|
|
|
|
state->error = checkColorValidity(info->color.colortype, info->color.bitdepth);
|
|
return state->error;
|
|
}
|
|
|
|
static unsigned unfilterScanline(unsigned char* recon, const unsigned char* scanline, const unsigned char* precon,
|
|
size_t bytewidth, unsigned char filterType, size_t length)
|
|
{
|
|
/*
|
|
For PNG filter method 0
|
|
unfilter a PNG image scanline by scanline. when the pixels are smaller than 1 byte,
|
|
the filter works byte per byte (bytewidth = 1)
|
|
precon is the previous unfiltered scanline, recon the result, scanline the current one
|
|
the incoming scanlines do NOT include the filtertype byte, that one is given in the parameter filterType instead
|
|
recon and scanline MAY be the same memory address! precon must be disjoint.
|
|
*/
|
|
|
|
size_t i;
|
|
switch(filterType)
|
|
{
|
|
case 0:
|
|
for(i = 0; i != length; ++i) recon[i] = scanline[i];
|
|
break;
|
|
case 1:
|
|
for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i];
|
|
for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + recon[i - bytewidth];
|
|
break;
|
|
case 2:
|
|
if(precon)
|
|
{
|
|
for(i = 0; i != length; ++i) recon[i] = scanline[i] + precon[i];
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i != length; ++i) recon[i] = scanline[i];
|
|
}
|
|
break;
|
|
case 3:
|
|
if(precon)
|
|
{
|
|
for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i] + precon[i] / 2;
|
|
for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) / 2);
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i];
|
|
for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + recon[i - bytewidth] / 2;
|
|
}
|
|
break;
|
|
case 4:
|
|
if(precon)
|
|
{
|
|
for(i = 0; i != bytewidth; ++i)
|
|
{
|
|
recon[i] = (scanline[i] + precon[i]); /*paethPredictor(0, precon[i], 0) is always precon[i]*/
|
|
}
|
|
for(i = bytewidth; i < length; ++i)
|
|
{
|
|
recon[i] = (scanline[i] + paethPredictor(recon[i - bytewidth], precon[i], precon[i - bytewidth]));
|
|
}
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i != bytewidth; ++i)
|
|
{
|
|
recon[i] = scanline[i];
|
|
}
|
|
for(i = bytewidth; i < length; ++i)
|
|
{
|
|
/*paethPredictor(recon[i - bytewidth], 0, 0) is always recon[i - bytewidth]*/
|
|
recon[i] = (scanline[i] + recon[i - bytewidth]);
|
|
}
|
|
}
|
|
break;
|
|
default: return 36; /*error: unexisting filter type given*/
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
|
|
{
|
|
/*
|
|
For PNG filter method 0
|
|
this function unfilters a single image (e.g. without interlacing this is called once, with Adam7 seven times)
|
|
out must have enough bytes allocated already, in must have the scanlines + 1 filtertype byte per scanline
|
|
w and h are image dimensions or dimensions of reduced image, bpp is bits per pixel
|
|
in and out are allowed to be the same memory address (but aren't the same size since in has the extra filter bytes)
|
|
*/
|
|
|
|
unsigned y;
|
|
unsigned char* prevline = 0;
|
|
|
|
/*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
|
|
size_t bytewidth = (bpp + 7) / 8;
|
|
size_t linebytes = (w * bpp + 7) / 8;
|
|
|
|
for(y = 0; y < h; ++y)
|
|
{
|
|
size_t outindex = linebytes * y;
|
|
size_t inindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
|
|
unsigned char filterType = in[inindex];
|
|
|
|
CERROR_TRY_RETURN(unfilterScanline(&out[outindex], &in[inindex + 1], prevline, bytewidth, filterType, linebytes));
|
|
|
|
prevline = &out[outindex];
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
in: Adam7 interlaced image, with no padding bits between scanlines, but between
|
|
reduced images so that each reduced image starts at a byte.
|
|
out: the same pixels, but re-ordered so that they're now a non-interlaced image with size w*h
|
|
bpp: bits per pixel
|
|
out has the following size in bits: w * h * bpp.
|
|
in is possibly bigger due to padding bits between reduced images.
|
|
out must be big enough AND must be 0 everywhere if bpp < 8 in the current implementation
|
|
(because that's likely a little bit faster)
|
|
NOTE: comments about padding bits are only relevant if bpp < 8
|
|
*/
|
|
static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
|
|
{
|
|
unsigned passw[7], passh[7];
|
|
size_t filter_passstart[8], padded_passstart[8], passstart[8];
|
|
unsigned i;
|
|
|
|
Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
|
|
|
|
if(bpp >= 8)
|
|
{
|
|
for(i = 0; i != 7; ++i)
|
|
{
|
|
unsigned x, y, b;
|
|
size_t bytewidth = bpp / 8;
|
|
for(y = 0; y < passh[i]; ++y)
|
|
for(x = 0; x < passw[i]; ++x)
|
|
{
|
|
size_t pixelinstart = passstart[i] + (y * passw[i] + x) * bytewidth;
|
|
size_t pixeloutstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth;
|
|
for(b = 0; b < bytewidth; ++b)
|
|
{
|
|
out[pixeloutstart + b] = in[pixelinstart + b];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/
|
|
{
|
|
for(i = 0; i != 7; ++i)
|
|
{
|
|
unsigned x, y, b;
|
|
unsigned ilinebits = bpp * passw[i];
|
|
unsigned olinebits = bpp * w;
|
|
size_t obp, ibp; /*bit pointers (for out and in buffer)*/
|
|
for(y = 0; y < passh[i]; ++y)
|
|
for(x = 0; x < passw[i]; ++x)
|
|
{
|
|
ibp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
|
|
obp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp;
|
|
for(b = 0; b < bpp; ++b)
|
|
{
|
|
unsigned char bit = readBitFromReversedStream(&ibp, in);
|
|
/*note that this function assumes the out buffer is completely 0, use setBitOfReversedStream otherwise*/
|
|
setBitOfReversedStream0(&obp, out, bit);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void removePaddingBits(unsigned char* out, const unsigned char* in,
|
|
size_t olinebits, size_t ilinebits, unsigned h)
|
|
{
|
|
/*
|
|
After filtering there are still padding bits if scanlines have non multiple of 8 bit amounts. They need
|
|
to be removed (except at last scanline of (Adam7-reduced) image) before working with pure image buffers
|
|
for the Adam7 code, the color convert code and the output to the user.
|
|
in and out are allowed to be the same buffer, in may also be higher but still overlapping; in must
|
|
have >= ilinebits*h bits, out must have >= olinebits*h bits, olinebits must be <= ilinebits
|
|
also used to move bits after earlier such operations happened, e.g. in a sequence of reduced images from Adam7
|
|
only useful if (ilinebits - olinebits) is a value in the range 1..7
|
|
*/
|
|
unsigned y;
|
|
size_t diff = ilinebits - olinebits;
|
|
size_t ibp = 0, obp = 0; /*input and output bit pointers*/
|
|
for(y = 0; y < h; ++y)
|
|
{
|
|
size_t x;
|
|
for(x = 0; x < olinebits; ++x)
|
|
{
|
|
unsigned char bit = readBitFromReversedStream(&ibp, in);
|
|
setBitOfReversedStream(&obp, out, bit);
|
|
}
|
|
ibp += diff;
|
|
}
|
|
}
|
|
|
|
/*out must be buffer big enough to contain full image, and in must contain the full decompressed data from
|
|
the IDAT chunks (with filter index bytes and possible padding bits)
|
|
return value is error*/
|
|
static unsigned postProcessScanlines(unsigned char* out, unsigned char* in,
|
|
unsigned w, unsigned h, const LodePNGInfo* info_png)
|
|
{
|
|
/*
|
|
This function converts the filtered-padded-interlaced data into pure 2D image buffer with the PNG's colortype.
|
|
Steps:
|
|
*) if no Adam7: 1) unfilter 2) remove padding bits (= posible extra bits per scanline if bpp < 8)
|
|
*) if adam7: 1) 7x unfilter 2) 7x remove padding bits 3) Adam7_deinterlace
|
|
NOTE: the in buffer will be overwritten with intermediate data!
|
|
*/
|
|
unsigned bpp = lodepng_get_bpp(&info_png->color);
|
|
if(bpp == 0) return 31; /*error: invalid colortype*/
|
|
|
|
if(info_png->interlace_method == 0)
|
|
{
|
|
if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8)
|
|
{
|
|
CERROR_TRY_RETURN(unfilter(in, in, w, h, bpp));
|
|
removePaddingBits(out, in, w * bpp, ((w * bpp + 7) / 8) * 8, h);
|
|
}
|
|
/*we can immediatly filter into the out buffer, no other steps needed*/
|
|
else CERROR_TRY_RETURN(unfilter(out, in, w, h, bpp));
|
|
}
|
|
else /*interlace_method is 1 (Adam7)*/
|
|
{
|
|
unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8];
|
|
unsigned i;
|
|
|
|
Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
|
|
|
|
for(i = 0; i != 7; ++i)
|
|
{
|
|
CERROR_TRY_RETURN(unfilter(&in[padded_passstart[i]], &in[filter_passstart[i]], passw[i], passh[i], bpp));
|
|
/*TODO: possible efficiency improvement: if in this reduced image the bits fit nicely in 1 scanline,
|
|
move bytes instead of bits or move not at all*/
|
|
if(bpp < 8)
|
|
{
|
|
/*remove padding bits in scanlines; after this there still may be padding
|
|
bits between the different reduced images: each reduced image still starts nicely at a byte*/
|
|
removePaddingBits(&in[passstart[i]], &in[padded_passstart[i]], passw[i] * bpp,
|
|
((passw[i] * bpp + 7) / 8) * 8, passh[i]);
|
|
}
|
|
}
|
|
|
|
Adam7_deinterlace(out, in, w, h, bpp);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static unsigned readChunk_PLTE(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength)
|
|
{
|
|
unsigned pos = 0, i;
|
|
if(color->palette) lodepng_free(color->palette);
|
|
color->palettesize = chunkLength / 3;
|
|
color->palette = (unsigned char*)lodepng_malloc(4 * color->palettesize);
|
|
if(!color->palette && color->palettesize)
|
|
{
|
|
color->palettesize = 0;
|
|
return 83; /*alloc fail*/
|
|
}
|
|
if(color->palettesize > 256) return 38; /*error: palette too big*/
|
|
|
|
for(i = 0; i != color->palettesize; ++i)
|
|
{
|
|
color->palette[4 * i + 0] = data[pos++]; /*R*/
|
|
color->palette[4 * i + 1] = data[pos++]; /*G*/
|
|
color->palette[4 * i + 2] = data[pos++]; /*B*/
|
|
color->palette[4 * i + 3] = 255; /*alpha*/
|
|
}
|
|
|
|
return 0; /* OK */
|
|
}
|
|
|
|
static unsigned readChunk_tRNS(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength)
|
|
{
|
|
unsigned i;
|
|
if(color->colortype == LCT_PALETTE)
|
|
{
|
|
/*error: more alpha values given than there are palette entries*/
|
|
if(chunkLength > color->palettesize) return 38;
|
|
|
|
for(i = 0; i != chunkLength; ++i) color->palette[4 * i + 3] = data[i];
|
|
}
|
|
else if(color->colortype == LCT_GREY)
|
|
{
|
|
/*error: this chunk must be 2 bytes for greyscale image*/
|
|
if(chunkLength != 2) return 30;
|
|
|
|
color->key_defined = 1;
|
|
color->key_r = color->key_g = color->key_b = 256u * data[0] + data[1];
|
|
}
|
|
else if(color->colortype == LCT_RGB)
|
|
{
|
|
/*error: this chunk must be 6 bytes for RGB image*/
|
|
if(chunkLength != 6) return 41;
|
|
|
|
color->key_defined = 1;
|
|
color->key_r = 256u * data[0] + data[1];
|
|
color->key_g = 256u * data[2] + data[3];
|
|
color->key_b = 256u * data[4] + data[5];
|
|
}
|
|
else return 42; /*error: tRNS chunk not allowed for other color models*/
|
|
|
|
return 0; /* OK */
|
|
}
|
|
|
|
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
/*background color chunk (bKGD)*/
|
|
static unsigned readChunk_bKGD(LodePNGInfo* info, const unsigned char* data, size_t chunkLength)
|
|
{
|
|
if(info->color.colortype == LCT_PALETTE)
|
|
{
|
|
/*error: this chunk must be 1 byte for indexed color image*/
|
|
if(chunkLength != 1) return 43;
|
|
|
|
info->background_defined = 1;
|
|
info->background_r = info->background_g = info->background_b = data[0];
|
|
}
|
|
else if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA)
|
|
{
|
|
/*error: this chunk must be 2 bytes for greyscale image*/
|
|
if(chunkLength != 2) return 44;
|
|
|
|
info->background_defined = 1;
|
|
info->background_r = info->background_g = info->background_b = 256u * data[0] + data[1];
|
|
}
|
|
else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA)
|
|
{
|
|
/*error: this chunk must be 6 bytes for greyscale image*/
|
|
if(chunkLength != 6) return 45;
|
|
|
|
info->background_defined = 1;
|
|
info->background_r = 256u * data[0] + data[1];
|
|
info->background_g = 256u * data[2] + data[3];
|
|
info->background_b = 256u * data[4] + data[5];
|
|
}
|
|
|
|
return 0; /* OK */
|
|
}
|
|
|
|
/*text chunk (tEXt)*/
|
|
static unsigned readChunk_tEXt(LodePNGInfo* info, const unsigned char* data, size_t chunkLength)
|
|
{
|
|
unsigned error = 0;
|
|
char *key = 0, *str = 0;
|
|
unsigned i;
|
|
|
|
while(!error) /*not really a while loop, only used to break on error*/
|
|
{
|
|
unsigned length, string2_begin;
|
|
|
|
length = 0;
|
|
while(length < chunkLength && data[length] != 0) ++length;
|
|
/*even though it's not allowed by the standard, no error is thrown if
|
|
there's no null termination char, if the text is empty*/
|
|
if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/
|
|
|
|
key = (char*)lodepng_malloc(length + 1);
|
|
if(!key) CERROR_BREAK(error, 83); /*alloc fail*/
|
|
|
|
key[length] = 0;
|
|
for(i = 0; i != length; ++i) key[i] = (char)data[i];
|
|
|
|
string2_begin = length + 1; /*skip keyword null terminator*/
|
|
|
|
length = chunkLength < string2_begin ? 0 : chunkLength - string2_begin;
|
|
str = (char*)lodepng_malloc(length + 1);
|
|
if(!str) CERROR_BREAK(error, 83); /*alloc fail*/
|
|
|
|
str[length] = 0;
|
|
for(i = 0; i != length; ++i) str[i] = (char)data[string2_begin + i];
|
|
|
|
error = lodepng_add_text(info, key, str);
|
|
|
|
break;
|
|
}
|
|
|
|
lodepng_free(key);
|
|
lodepng_free(str);
|
|
|
|
return error;
|
|
}
|
|
|
|
/*compressed text chunk (zTXt)*/
|
|
static unsigned readChunk_zTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings,
|
|
const unsigned char* data, size_t chunkLength)
|
|
{
|
|
unsigned error = 0;
|
|
unsigned i;
|
|
|
|
unsigned length, string2_begin;
|
|
char *key = 0;
|
|
ucvector decoded;
|
|
|
|
ucvector_init(&decoded);
|
|
|
|
while(!error) /*not really a while loop, only used to break on error*/
|
|
{
|
|
for(length = 0; length < chunkLength && data[length] != 0; ++length) ;
|
|
if(length + 2 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/
|
|
if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/
|
|
|
|
key = (char*)lodepng_malloc(length + 1);
|
|
if(!key) CERROR_BREAK(error, 83); /*alloc fail*/
|
|
|
|
key[length] = 0;
|
|
for(i = 0; i != length; ++i) key[i] = (char)data[i];
|
|
|
|
if(data[length + 1] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/
|
|
|
|
string2_begin = length + 2;
|
|
if(string2_begin > chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/
|
|
|
|
length = chunkLength - string2_begin;
|
|
/*will fail if zlib error, e.g. if length is too small*/
|
|
error = zlib_decompress(&decoded.data, &decoded.size,
|
|
(unsigned char*)(&data[string2_begin]),
|
|
length, zlibsettings);
|
|
if(error) break;
|
|
ucvector_push_back(&decoded, 0);
|
|
|
|
error = lodepng_add_text(info, key, (char*)decoded.data);
|
|
|
|
break;
|
|
}
|
|
|
|
lodepng_free(key);
|
|
ucvector_cleanup(&decoded);
|
|
|
|
return error;
|
|
}
|
|
|
|
/*international text chunk (iTXt)*/
|
|
static unsigned readChunk_iTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings,
|
|
const unsigned char* data, size_t chunkLength)
|
|
{
|
|
unsigned error = 0;
|
|
unsigned i;
|
|
|
|
unsigned length, begin, compressed;
|
|
char *key = 0, *langtag = 0, *transkey = 0;
|
|
ucvector decoded;
|
|
ucvector_init(&decoded);
|
|
|
|
while(!error) /*not really a while loop, only used to break on error*/
|
|
{
|
|
/*Quick check if the chunk length isn't too small. Even without check
|
|
it'd still fail with other error checks below if it's too short. This just gives a different error code.*/
|
|
if(chunkLength < 5) CERROR_BREAK(error, 30); /*iTXt chunk too short*/
|
|
|
|
/*read the key*/
|
|
for(length = 0; length < chunkLength && data[length] != 0; ++length) ;
|
|
if(length + 3 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination char, corrupt?*/
|
|
if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/
|
|
|
|
key = (char*)lodepng_malloc(length + 1);
|
|
if(!key) CERROR_BREAK(error, 83); /*alloc fail*/
|
|
|
|
key[length] = 0;
|
|
for(i = 0; i != length; ++i) key[i] = (char)data[i];
|
|
|
|
/*read the compression method*/
|
|
compressed = data[length + 1];
|
|
if(data[length + 2] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/
|
|
|
|
/*even though it's not allowed by the standard, no error is thrown if
|
|
there's no null termination char, if the text is empty for the next 3 texts*/
|
|
|
|
/*read the langtag*/
|
|
begin = length + 3;
|
|
length = 0;
|
|
for(i = begin; i < chunkLength && data[i] != 0; ++i) ++length;
|
|
|
|
langtag = (char*)lodepng_malloc(length + 1);
|
|
if(!langtag) CERROR_BREAK(error, 83); /*alloc fail*/
|
|
|
|
langtag[length] = 0;
|
|
for(i = 0; i != length; ++i) langtag[i] = (char)data[begin + i];
|
|
|
|
/*read the transkey*/
|
|
begin += length + 1;
|
|
length = 0;
|
|
for(i = begin; i < chunkLength && data[i] != 0; ++i) ++length;
|
|
|
|
transkey = (char*)lodepng_malloc(length + 1);
|
|
if(!transkey) CERROR_BREAK(error, 83); /*alloc fail*/
|
|
|
|
transkey[length] = 0;
|
|
for(i = 0; i != length; ++i) transkey[i] = (char)data[begin + i];
|
|
|
|
/*read the actual text*/
|
|
begin += length + 1;
|
|
|
|
length = chunkLength < begin ? 0 : chunkLength - begin;
|
|
|
|
if(compressed)
|
|
{
|
|
/*will fail if zlib error, e.g. if length is too small*/
|
|
error = zlib_decompress(&decoded.data, &decoded.size,
|
|
(unsigned char*)(&data[begin]),
|
|
length, zlibsettings);
|
|
if(error) break;
|
|
if(decoded.allocsize < decoded.size) decoded.allocsize = decoded.size;
|
|
ucvector_push_back(&decoded, 0);
|
|
}
|
|
else
|
|
{
|
|
if(!ucvector_resize(&decoded, length + 1)) CERROR_BREAK(error, 83 /*alloc fail*/);
|
|
|
|
decoded.data[length] = 0;
|
|
for(i = 0; i != length; ++i) decoded.data[i] = data[begin + i];
|
|
}
|
|
|
|
error = lodepng_add_itext(info, key, langtag, transkey, (char*)decoded.data);
|
|
|
|
break;
|
|
}
|
|
|
|
lodepng_free(key);
|
|
lodepng_free(langtag);
|
|
lodepng_free(transkey);
|
|
ucvector_cleanup(&decoded);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned readChunk_tIME(LodePNGInfo* info, const unsigned char* data, size_t chunkLength)
|
|
{
|
|
if(chunkLength != 7) return 73; /*invalid tIME chunk size*/
|
|
|
|
info->time_defined = 1;
|
|
info->time.year = 256u * data[0] + data[1];
|
|
info->time.month = data[2];
|
|
info->time.day = data[3];
|
|
info->time.hour = data[4];
|
|
info->time.minute = data[5];
|
|
info->time.second = data[6];
|
|
|
|
return 0; /* OK */
|
|
}
|
|
|
|
static unsigned readChunk_pHYs(LodePNGInfo* info, const unsigned char* data, size_t chunkLength)
|
|
{
|
|
if(chunkLength != 9) return 74; /*invalid pHYs chunk size*/
|
|
|
|
info->phys_defined = 1;
|
|
info->phys_x = 16777216u * data[0] + 65536u * data[1] + 256u * data[2] + data[3];
|
|
info->phys_y = 16777216u * data[4] + 65536u * data[5] + 256u * data[6] + data[7];
|
|
info->phys_unit = data[8];
|
|
|
|
return 0; /* OK */
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
|
|
/*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/
|
|
static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h,
|
|
LodePNGState* state,
|
|
const unsigned char* in, size_t insize)
|
|
{
|
|
unsigned char IEND = 0;
|
|
const unsigned char* chunk;
|
|
size_t i;
|
|
ucvector idat; /*the data from idat chunks*/
|
|
ucvector scanlines;
|
|
size_t predict;
|
|
size_t numpixels;
|
|
|
|
/*for unknown chunk order*/
|
|
unsigned unknown = 0;
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
unsigned critical_pos = 1; /*1 = after IHDR, 2 = after PLTE, 3 = after IDAT*/
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
|
|
/*provide some proper output values if error will happen*/
|
|
*out = 0;
|
|
|
|
state->error = lodepng_inspect(w, h, state, in, insize); /*reads header and resets other parameters in state->info_png*/
|
|
if(state->error) return;
|
|
|
|
numpixels = *w * *h;
|
|
|
|
/*multiplication overflow*/
|
|
if(*h != 0 && numpixels / *h != *w) CERROR_RETURN(state->error, 92);
|
|
/*multiplication overflow possible further below. Allows up to 2^31-1 pixel
|
|
bytes with 16-bit RGBA, the rest is room for filter bytes.*/
|
|
if(numpixels > 268435455) CERROR_RETURN(state->error, 92);
|
|
|
|
ucvector_init(&idat);
|
|
chunk = &in[33]; /*first byte of the first chunk after the header*/
|
|
|
|
/*loop through the chunks, ignoring unknown chunks and stopping at IEND chunk.
|
|
IDAT data is put at the start of the in buffer*/
|
|
while(!IEND && !state->error)
|
|
{
|
|
unsigned chunkLength;
|
|
const unsigned char* data; /*the data in the chunk*/
|
|
|
|
/*error: size of the in buffer too small to contain next chunk*/
|
|
if((size_t)((chunk - in) + 12) > insize || chunk < in) CERROR_BREAK(state->error, 30);
|
|
|
|
/*length of the data of the chunk, excluding the length bytes, chunk type and CRC bytes*/
|
|
chunkLength = lodepng_chunk_length(chunk);
|
|
/*error: chunk length larger than the max PNG chunk size*/
|
|
if(chunkLength > 2147483647) CERROR_BREAK(state->error, 63);
|
|
|
|
if((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) < in)
|
|
{
|
|
CERROR_BREAK(state->error, 64); /*error: size of the in buffer too small to contain next chunk*/
|
|
}
|
|
|
|
data = lodepng_chunk_data_const(chunk);
|
|
|
|
/*IDAT chunk, containing compressed image data*/
|
|
if(lodepng_chunk_type_equals(chunk, "IDAT"))
|
|
{
|
|
size_t oldsize = idat.size;
|
|
if(!ucvector_resize(&idat, oldsize + chunkLength)) CERROR_BREAK(state->error, 83 /*alloc fail*/);
|
|
for(i = 0; i != chunkLength; ++i) idat.data[oldsize + i] = data[i];
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
critical_pos = 3;
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
}
|
|
/*IEND chunk*/
|
|
else if(lodepng_chunk_type_equals(chunk, "IEND"))
|
|
{
|
|
IEND = 1;
|
|
}
|
|
/*palette chunk (PLTE)*/
|
|
else if(lodepng_chunk_type_equals(chunk, "PLTE"))
|
|
{
|
|
state->error = readChunk_PLTE(&state->info_png.color, data, chunkLength);
|
|
if(state->error) break;
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
critical_pos = 2;
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
}
|
|
/*palette transparency chunk (tRNS)*/
|
|
else if(lodepng_chunk_type_equals(chunk, "tRNS"))
|
|
{
|
|
state->error = readChunk_tRNS(&state->info_png.color, data, chunkLength);
|
|
if(state->error) break;
|
|
}
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
/*background color chunk (bKGD)*/
|
|
else if(lodepng_chunk_type_equals(chunk, "bKGD"))
|
|
{
|
|
state->error = readChunk_bKGD(&state->info_png, data, chunkLength);
|
|
if(state->error) break;
|
|
}
|
|
/*text chunk (tEXt)*/
|
|
else if(lodepng_chunk_type_equals(chunk, "tEXt"))
|
|
{
|
|
if(state->decoder.read_text_chunks)
|
|
{
|
|
state->error = readChunk_tEXt(&state->info_png, data, chunkLength);
|
|
if(state->error) break;
|
|
}
|
|
}
|
|
/*compressed text chunk (zTXt)*/
|
|
else if(lodepng_chunk_type_equals(chunk, "zTXt"))
|
|
{
|
|
if(state->decoder.read_text_chunks)
|
|
{
|
|
state->error = readChunk_zTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength);
|
|
if(state->error) break;
|
|
}
|
|
}
|
|
/*international text chunk (iTXt)*/
|
|
else if(lodepng_chunk_type_equals(chunk, "iTXt"))
|
|
{
|
|
if(state->decoder.read_text_chunks)
|
|
{
|
|
state->error = readChunk_iTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength);
|
|
if(state->error) break;
|
|
}
|
|
}
|
|
else if(lodepng_chunk_type_equals(chunk, "tIME"))
|
|
{
|
|
state->error = readChunk_tIME(&state->info_png, data, chunkLength);
|
|
if(state->error) break;
|
|
}
|
|
else if(lodepng_chunk_type_equals(chunk, "pHYs"))
|
|
{
|
|
state->error = readChunk_pHYs(&state->info_png, data, chunkLength);
|
|
if(state->error) break;
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
else /*it's not an implemented chunk type, so ignore it: skip over the data*/
|
|
{
|
|
/*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/
|
|
if(!lodepng_chunk_ancillary(chunk)) CERROR_BREAK(state->error, 69);
|
|
|
|
unknown = 1;
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
if(state->decoder.remember_unknown_chunks)
|
|
{
|
|
state->error = lodepng_chunk_append(&state->info_png.unknown_chunks_data[critical_pos - 1],
|
|
&state->info_png.unknown_chunks_size[critical_pos - 1], chunk);
|
|
if(state->error) break;
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
}
|
|
|
|
if(!state->decoder.ignore_crc && !unknown) /*check CRC if wanted, only on known chunk types*/
|
|
{
|
|
if(lodepng_chunk_check_crc(chunk)) CERROR_BREAK(state->error, 57); /*invalid CRC*/
|
|
}
|
|
|
|
if(!IEND) chunk = lodepng_chunk_next_const(chunk);
|
|
}
|
|
|
|
ucvector_init(&scanlines);
|
|
/*predict output size, to allocate exact size for output buffer to avoid more dynamic allocation.
|
|
If the decompressed size does not match the prediction, the image must be corrupt.*/
|
|
if(state->info_png.interlace_method == 0)
|
|
{
|
|
/*The extra *h is added because this are the filter bytes every scanline starts with*/
|
|
predict = lodepng_get_raw_size_idat(*w, *h, &state->info_png.color) + *h;
|
|
}
|
|
else
|
|
{
|
|
/*Adam-7 interlaced: predicted size is the sum of the 7 sub-images sizes*/
|
|
const LodePNGColorMode* color = &state->info_png.color;
|
|
predict = 0;
|
|
predict += lodepng_get_raw_size_idat((*w + 7) / 8, (*h + 7) / 8, color) + (*h + 7) / 8;
|
|
if(*w > 4) predict += lodepng_get_raw_size_idat((*w + 3) / 8, (*h + 7) / 8, color) + (*h + 7) / 8;
|
|
predict += lodepng_get_raw_size_idat((*w + 3) / 4, (*h + 3) / 8, color) + (*h + 3) / 8;
|
|
if(*w > 2) predict += lodepng_get_raw_size_idat((*w + 1) / 4, (*h + 3) / 4, color) + (*h + 3) / 4;
|
|
predict += lodepng_get_raw_size_idat((*w + 1) / 2, (*h + 1) / 4, color) + (*h + 1) / 4;
|
|
if(*w > 1) predict += lodepng_get_raw_size_idat((*w + 0) / 2, (*h + 1) / 2, color) + (*h + 1) / 2;
|
|
predict += lodepng_get_raw_size_idat((*w + 0) / 1, (*h + 0) / 2, color) + (*h + 0) / 2;
|
|
}
|
|
if(!state->error && !ucvector_reserve(&scanlines, predict)) state->error = 83; /*alloc fail*/
|
|
if(!state->error)
|
|
{
|
|
state->error = zlib_decompress(&scanlines.data, &scanlines.size, idat.data,
|
|
idat.size, &state->decoder.zlibsettings);
|
|
if(!state->error && scanlines.size != predict) state->error = 91; /*decompressed size doesn't match prediction*/
|
|
}
|
|
ucvector_cleanup(&idat);
|
|
|
|
if(!state->error)
|
|
{
|
|
size_t outsize = lodepng_get_raw_size(*w, *h, &state->info_png.color);
|
|
ucvector outv;
|
|
ucvector_init(&outv);
|
|
if(!ucvector_resizev(&outv, outsize, 0)) state->error = 83; /*alloc fail*/
|
|
if(!state->error) state->error = postProcessScanlines(outv.data, scanlines.data, *w, *h, &state->info_png);
|
|
*out = outv.data;
|
|
}
|
|
ucvector_cleanup(&scanlines);
|
|
}
|
|
|
|
unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h,
|
|
LodePNGState* state,
|
|
const unsigned char* in, size_t insize)
|
|
{
|
|
*out = 0;
|
|
decodeGeneric(out, w, h, state, in, insize);
|
|
if(state->error) return state->error;
|
|
if(!state->decoder.color_convert || lodepng_color_mode_equal(&state->info_raw, &state->info_png.color))
|
|
{
|
|
/*same color type, no copying or converting of data needed*/
|
|
/*store the info_png color settings on the info_raw so that the info_raw still reflects what colortype
|
|
the raw image has to the end user*/
|
|
if(!state->decoder.color_convert)
|
|
{
|
|
state->error = lodepng_color_mode_copy(&state->info_raw, &state->info_png.color);
|
|
if(state->error) return state->error;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/*color conversion needed; sort of copy of the data*/
|
|
unsigned char* data = *out;
|
|
size_t outsize;
|
|
|
|
/*TODO: check if this works according to the statement in the documentation: "The converter can convert
|
|
from greyscale input color type, to 8-bit greyscale or greyscale with alpha"*/
|
|
if(!(state->info_raw.colortype == LCT_RGB || state->info_raw.colortype == LCT_RGBA)
|
|
&& !(state->info_raw.bitdepth == 8))
|
|
{
|
|
return 56; /*unsupported color mode conversion*/
|
|
}
|
|
|
|
outsize = lodepng_get_raw_size(*w, *h, &state->info_raw);
|
|
*out = (unsigned char*)lodepng_malloc(outsize);
|
|
if(!(*out))
|
|
{
|
|
state->error = 83; /*alloc fail*/
|
|
}
|
|
else state->error = lodepng_convert(*out, data, &state->info_raw,
|
|
&state->info_png.color, *w, *h);
|
|
lodepng_free(data);
|
|
}
|
|
return state->error;
|
|
}
|
|
|
|
unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in,
|
|
size_t insize, LodePNGColorType colortype, unsigned bitdepth)
|
|
{
|
|
unsigned error;
|
|
LodePNGState state;
|
|
lodepng_state_init(&state);
|
|
state.info_raw.colortype = colortype;
|
|
state.info_raw.bitdepth = bitdepth;
|
|
error = lodepng_decode(out, w, h, &state, in, insize);
|
|
lodepng_state_cleanup(&state);
|
|
return error;
|
|
}
|
|
|
|
unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize)
|
|
{
|
|
return lodepng_decode_memory(out, w, h, in, insize, LCT_RGBA, 8);
|
|
}
|
|
|
|
unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize)
|
|
{
|
|
return lodepng_decode_memory(out, w, h, in, insize, LCT_RGB, 8);
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_DISK
|
|
unsigned lodepng_decode_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename,
|
|
LodePNGColorType colortype, unsigned bitdepth)
|
|
{
|
|
unsigned char* buffer;
|
|
size_t buffersize;
|
|
unsigned error;
|
|
error = lodepng_load_file(&buffer, &buffersize, filename);
|
|
if(!error) error = lodepng_decode_memory(out, w, h, buffer, buffersize, colortype, bitdepth);
|
|
lodepng_free(buffer);
|
|
return error;
|
|
}
|
|
|
|
unsigned lodepng_decode32_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename)
|
|
{
|
|
return lodepng_decode_file(out, w, h, filename, LCT_RGBA, 8);
|
|
}
|
|
|
|
unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename)
|
|
{
|
|
return lodepng_decode_file(out, w, h, filename, LCT_RGB, 8);
|
|
}
|
|
#endif /*LODEPNG_COMPILE_DISK*/
|
|
|
|
void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings)
|
|
{
|
|
settings->color_convert = 1;
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
settings->read_text_chunks = 1;
|
|
settings->remember_unknown_chunks = 0;
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
settings->ignore_crc = 0;
|
|
lodepng_decompress_settings_init(&settings->zlibsettings);
|
|
}
|
|
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
|
|
#if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER)
|
|
|
|
void lodepng_state_init(LodePNGState* state)
|
|
{
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
lodepng_decoder_settings_init(&state->decoder);
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
lodepng_encoder_settings_init(&state->encoder);
|
|
#endif /*LODEPNG_COMPILE_ENCODER*/
|
|
lodepng_color_mode_init(&state->info_raw);
|
|
lodepng_info_init(&state->info_png);
|
|
state->error = 1;
|
|
}
|
|
|
|
void lodepng_state_cleanup(LodePNGState* state)
|
|
{
|
|
lodepng_color_mode_cleanup(&state->info_raw);
|
|
lodepng_info_cleanup(&state->info_png);
|
|
}
|
|
|
|
void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source)
|
|
{
|
|
lodepng_state_cleanup(dest);
|
|
*dest = *source;
|
|
lodepng_color_mode_init(&dest->info_raw);
|
|
lodepng_info_init(&dest->info_png);
|
|
dest->error = lodepng_color_mode_copy(&dest->info_raw, &source->info_raw); if(dest->error) return;
|
|
dest->error = lodepng_info_copy(&dest->info_png, &source->info_png); if(dest->error) return;
|
|
}
|
|
|
|
#endif /* defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) */
|
|
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / PNG Encoder / */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
/*chunkName must be string of 4 characters*/
|
|
static unsigned addChunk(ucvector* out, const char* chunkName, const unsigned char* data, size_t length)
|
|
{
|
|
CERROR_TRY_RETURN(lodepng_chunk_create(&out->data, &out->size, (unsigned)length, chunkName, data));
|
|
out->allocsize = out->size; /*fix the allocsize again*/
|
|
return 0;
|
|
}
|
|
|
|
static void writeSignature(ucvector* out)
|
|
{
|
|
/*8 bytes PNG signature, aka the magic bytes*/
|
|
ucvector_push_back(out, 137);
|
|
ucvector_push_back(out, 80);
|
|
ucvector_push_back(out, 78);
|
|
ucvector_push_back(out, 71);
|
|
ucvector_push_back(out, 13);
|
|
ucvector_push_back(out, 10);
|
|
ucvector_push_back(out, 26);
|
|
ucvector_push_back(out, 10);
|
|
}
|
|
|
|
static unsigned addChunk_IHDR(ucvector* out, unsigned w, unsigned h,
|
|
LodePNGColorType colortype, unsigned bitdepth, unsigned interlace_method)
|
|
{
|
|
unsigned error = 0;
|
|
ucvector header;
|
|
ucvector_init(&header);
|
|
|
|
lodepng_add32bitInt(&header, w); /*width*/
|
|
lodepng_add32bitInt(&header, h); /*height*/
|
|
ucvector_push_back(&header, (unsigned char)bitdepth); /*bit depth*/
|
|
ucvector_push_back(&header, (unsigned char)colortype); /*color type*/
|
|
ucvector_push_back(&header, 0); /*compression method*/
|
|
ucvector_push_back(&header, 0); /*filter method*/
|
|
ucvector_push_back(&header, interlace_method); /*interlace method*/
|
|
|
|
error = addChunk(out, "IHDR", header.data, header.size);
|
|
ucvector_cleanup(&header);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_PLTE(ucvector* out, const LodePNGColorMode* info)
|
|
{
|
|
unsigned error = 0;
|
|
size_t i;
|
|
ucvector PLTE;
|
|
ucvector_init(&PLTE);
|
|
for(i = 0; i != info->palettesize * 4; ++i)
|
|
{
|
|
/*add all channels except alpha channel*/
|
|
if(i % 4 != 3) ucvector_push_back(&PLTE, info->palette[i]);
|
|
}
|
|
error = addChunk(out, "PLTE", PLTE.data, PLTE.size);
|
|
ucvector_cleanup(&PLTE);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_tRNS(ucvector* out, const LodePNGColorMode* info)
|
|
{
|
|
unsigned error = 0;
|
|
size_t i;
|
|
ucvector tRNS;
|
|
ucvector_init(&tRNS);
|
|
if(info->colortype == LCT_PALETTE)
|
|
{
|
|
size_t amount = info->palettesize;
|
|
/*the tail of palette values that all have 255 as alpha, does not have to be encoded*/
|
|
for(i = info->palettesize; i != 0; --i)
|
|
{
|
|
if(info->palette[4 * (i - 1) + 3] == 255) --amount;
|
|
else break;
|
|
}
|
|
/*add only alpha channel*/
|
|
for(i = 0; i != amount; ++i) ucvector_push_back(&tRNS, info->palette[4 * i + 3]);
|
|
}
|
|
else if(info->colortype == LCT_GREY)
|
|
{
|
|
if(info->key_defined)
|
|
{
|
|
ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256));
|
|
ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256));
|
|
}
|
|
}
|
|
else if(info->colortype == LCT_RGB)
|
|
{
|
|
if(info->key_defined)
|
|
{
|
|
ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256));
|
|
ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256));
|
|
ucvector_push_back(&tRNS, (unsigned char)(info->key_g / 256));
|
|
ucvector_push_back(&tRNS, (unsigned char)(info->key_g % 256));
|
|
ucvector_push_back(&tRNS, (unsigned char)(info->key_b / 256));
|
|
ucvector_push_back(&tRNS, (unsigned char)(info->key_b % 256));
|
|
}
|
|
}
|
|
|
|
error = addChunk(out, "tRNS", tRNS.data, tRNS.size);
|
|
ucvector_cleanup(&tRNS);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_IDAT(ucvector* out, const unsigned char* data, size_t datasize,
|
|
LodePNGCompressSettings* zlibsettings)
|
|
{
|
|
ucvector zlibdata;
|
|
unsigned error = 0;
|
|
|
|
/*compress with the Zlib compressor*/
|
|
ucvector_init(&zlibdata);
|
|
error = zlib_compress(&zlibdata.data, &zlibdata.size, data, datasize, zlibsettings);
|
|
if(!error) error = addChunk(out, "IDAT", zlibdata.data, zlibdata.size);
|
|
ucvector_cleanup(&zlibdata);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_IEND(ucvector* out)
|
|
{
|
|
unsigned error = 0;
|
|
error = addChunk(out, "IEND", 0, 0);
|
|
return error;
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
|
|
static unsigned addChunk_tEXt(ucvector* out, const char* keyword, const char* textstring)
|
|
{
|
|
unsigned error = 0;
|
|
size_t i;
|
|
ucvector text;
|
|
ucvector_init(&text);
|
|
for(i = 0; keyword[i] != 0; ++i) ucvector_push_back(&text, (unsigned char)keyword[i]);
|
|
if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/
|
|
ucvector_push_back(&text, 0); /*0 termination char*/
|
|
for(i = 0; textstring[i] != 0; ++i) ucvector_push_back(&text, (unsigned char)textstring[i]);
|
|
error = addChunk(out, "tEXt", text.data, text.size);
|
|
ucvector_cleanup(&text);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_zTXt(ucvector* out, const char* keyword, const char* textstring,
|
|
LodePNGCompressSettings* zlibsettings)
|
|
{
|
|
unsigned error = 0;
|
|
ucvector data, compressed;
|
|
size_t i, textsize = strlen(textstring);
|
|
|
|
ucvector_init(&data);
|
|
ucvector_init(&compressed);
|
|
for(i = 0; keyword[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)keyword[i]);
|
|
if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/
|
|
ucvector_push_back(&data, 0); /*0 termination char*/
|
|
ucvector_push_back(&data, 0); /*compression method: 0*/
|
|
|
|
error = zlib_compress(&compressed.data, &compressed.size,
|
|
(unsigned char*)textstring, textsize, zlibsettings);
|
|
if(!error)
|
|
{
|
|
for(i = 0; i != compressed.size; ++i) ucvector_push_back(&data, compressed.data[i]);
|
|
error = addChunk(out, "zTXt", data.data, data.size);
|
|
}
|
|
|
|
ucvector_cleanup(&compressed);
|
|
ucvector_cleanup(&data);
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_iTXt(ucvector* out, unsigned compressed, const char* keyword, const char* langtag,
|
|
const char* transkey, const char* textstring, LodePNGCompressSettings* zlibsettings)
|
|
{
|
|
unsigned error = 0;
|
|
ucvector data;
|
|
size_t i, textsize = strlen(textstring);
|
|
|
|
ucvector_init(&data);
|
|
|
|
for(i = 0; keyword[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)keyword[i]);
|
|
if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/
|
|
ucvector_push_back(&data, 0); /*null termination char*/
|
|
ucvector_push_back(&data, compressed ? 1 : 0); /*compression flag*/
|
|
ucvector_push_back(&data, 0); /*compression method*/
|
|
for(i = 0; langtag[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)langtag[i]);
|
|
ucvector_push_back(&data, 0); /*null termination char*/
|
|
for(i = 0; transkey[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)transkey[i]);
|
|
ucvector_push_back(&data, 0); /*null termination char*/
|
|
|
|
if(compressed)
|
|
{
|
|
ucvector compressed_data;
|
|
ucvector_init(&compressed_data);
|
|
error = zlib_compress(&compressed_data.data, &compressed_data.size,
|
|
(unsigned char*)textstring, textsize, zlibsettings);
|
|
if(!error)
|
|
{
|
|
for(i = 0; i != compressed_data.size; ++i) ucvector_push_back(&data, compressed_data.data[i]);
|
|
}
|
|
ucvector_cleanup(&compressed_data);
|
|
}
|
|
else /*not compressed*/
|
|
{
|
|
for(i = 0; textstring[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)textstring[i]);
|
|
}
|
|
|
|
if(!error) error = addChunk(out, "iTXt", data.data, data.size);
|
|
ucvector_cleanup(&data);
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_bKGD(ucvector* out, const LodePNGInfo* info)
|
|
{
|
|
unsigned error = 0;
|
|
ucvector bKGD;
|
|
ucvector_init(&bKGD);
|
|
if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA)
|
|
{
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256));
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256));
|
|
}
|
|
else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA)
|
|
{
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256));
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256));
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_g / 256));
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_g % 256));
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_b / 256));
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_b % 256));
|
|
}
|
|
else if(info->color.colortype == LCT_PALETTE)
|
|
{
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256)); /*palette index*/
|
|
}
|
|
|
|
error = addChunk(out, "bKGD", bKGD.data, bKGD.size);
|
|
ucvector_cleanup(&bKGD);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_tIME(ucvector* out, const LodePNGTime* time)
|
|
{
|
|
unsigned error = 0;
|
|
unsigned char* data = (unsigned char*)lodepng_malloc(7);
|
|
if(!data) return 83; /*alloc fail*/
|
|
data[0] = (unsigned char)(time->year / 256);
|
|
data[1] = (unsigned char)(time->year % 256);
|
|
data[2] = (unsigned char)time->month;
|
|
data[3] = (unsigned char)time->day;
|
|
data[4] = (unsigned char)time->hour;
|
|
data[5] = (unsigned char)time->minute;
|
|
data[6] = (unsigned char)time->second;
|
|
error = addChunk(out, "tIME", data, 7);
|
|
lodepng_free(data);
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_pHYs(ucvector* out, const LodePNGInfo* info)
|
|
{
|
|
unsigned error = 0;
|
|
ucvector data;
|
|
ucvector_init(&data);
|
|
|
|
lodepng_add32bitInt(&data, info->phys_x);
|
|
lodepng_add32bitInt(&data, info->phys_y);
|
|
ucvector_push_back(&data, info->phys_unit);
|
|
|
|
error = addChunk(out, "pHYs", data.data, data.size);
|
|
ucvector_cleanup(&data);
|
|
|
|
return error;
|
|
}
|
|
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
|
|
static void filterScanline(unsigned char* out, const unsigned char* scanline, const unsigned char* prevline,
|
|
size_t length, size_t bytewidth, unsigned char filterType)
|
|
{
|
|
size_t i;
|
|
switch(filterType)
|
|
{
|
|
case 0: /*None*/
|
|
for(i = 0; i != length; ++i) out[i] = scanline[i];
|
|
break;
|
|
case 1: /*Sub*/
|
|
for(i = 0; i != bytewidth; ++i) out[i] = scanline[i];
|
|
for(i = bytewidth; i < length; ++i) out[i] = scanline[i] - scanline[i - bytewidth];
|
|
break;
|
|
case 2: /*Up*/
|
|
if(prevline)
|
|
{
|
|
for(i = 0; i != length; ++i) out[i] = scanline[i] - prevline[i];
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i != length; ++i) out[i] = scanline[i];
|
|
}
|
|
break;
|
|
case 3: /*Average*/
|
|
if(prevline)
|
|
{
|
|
for(i = 0; i != bytewidth; ++i) out[i] = scanline[i] - prevline[i] / 2;
|
|
for(i = bytewidth; i < length; ++i) out[i] = scanline[i] - ((scanline[i - bytewidth] + prevline[i]) / 2);
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i != bytewidth; ++i) out[i] = scanline[i];
|
|
for(i = bytewidth; i < length; ++i) out[i] = scanline[i] - scanline[i - bytewidth] / 2;
|
|
}
|
|
break;
|
|
case 4: /*Paeth*/
|
|
if(prevline)
|
|
{
|
|
/*paethPredictor(0, prevline[i], 0) is always prevline[i]*/
|
|
for(i = 0; i != bytewidth; ++i) out[i] = (scanline[i] - prevline[i]);
|
|
for(i = bytewidth; i < length; ++i)
|
|
{
|
|
out[i] = (scanline[i] - paethPredictor(scanline[i - bytewidth], prevline[i], prevline[i - bytewidth]));
|
|
}
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i != bytewidth; ++i) out[i] = scanline[i];
|
|
/*paethPredictor(scanline[i - bytewidth], 0, 0) is always scanline[i - bytewidth]*/
|
|
for(i = bytewidth; i < length; ++i) out[i] = (scanline[i] - scanline[i - bytewidth]);
|
|
}
|
|
break;
|
|
default: return; /*unexisting filter type given*/
|
|
}
|
|
}
|
|
|
|
/* log2 approximation. A slight bit faster than std::log. */
|
|
static float flog2(float f)
|
|
{
|
|
float result = 0;
|
|
while(f > 32) { result += 4; f /= 16; }
|
|
while(f > 2) { ++result; f /= 2; }
|
|
return result + 1.442695f * (f * f * f / 3 - 3 * f * f / 2 + 3 * f - 1.83333f);
|
|
}
|
|
|
|
static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h,
|
|
const LodePNGColorMode* info, const LodePNGEncoderSettings* settings)
|
|
{
|
|
/*
|
|
For PNG filter method 0
|
|
out must be a buffer with as size: h + (w * h * bpp + 7) / 8, because there are
|
|
the scanlines with 1 extra byte per scanline
|
|
*/
|
|
|
|
unsigned bpp = lodepng_get_bpp(info);
|
|
/*the width of a scanline in bytes, not including the filter type*/
|
|
size_t linebytes = (w * bpp + 7) / 8;
|
|
/*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
|
|
size_t bytewidth = (bpp + 7) / 8;
|
|
const unsigned char* prevline = 0;
|
|
unsigned x, y;
|
|
unsigned error = 0;
|
|
LodePNGFilterStrategy strategy = settings->filter_strategy;
|
|
|
|
/*
|
|
There is a heuristic called the minimum sum of absolute differences heuristic, suggested by the PNG standard:
|
|
* If the image type is Palette, or the bit depth is smaller than 8, then do not filter the image (i.e.
|
|
use fixed filtering, with the filter None).
|
|
* (The other case) If the image type is Grayscale or RGB (with or without Alpha), and the bit depth is
|
|
not smaller than 8, then use adaptive filtering heuristic as follows: independently for each row, apply
|
|
all five filters and select the filter that produces the smallest sum of absolute values per row.
|
|
This heuristic is used if filter strategy is LFS_MINSUM and filter_palette_zero is true.
|
|
|
|
If filter_palette_zero is true and filter_strategy is not LFS_MINSUM, the above heuristic is followed,
|
|
but for "the other case", whatever strategy filter_strategy is set to instead of the minimum sum
|
|
heuristic is used.
|
|
*/
|
|
if(settings->filter_palette_zero &&
|
|
(info->colortype == LCT_PALETTE || info->bitdepth < 8)) strategy = LFS_ZERO;
|
|
|
|
if(bpp == 0) return 31; /*error: invalid color type*/
|
|
|
|
if(strategy == LFS_ZERO)
|
|
{
|
|
for(y = 0; y != h; ++y)
|
|
{
|
|
size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
|
|
size_t inindex = linebytes * y;
|
|
out[outindex] = 0; /*filter type byte*/
|
|
filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, 0);
|
|
prevline = &in[inindex];
|
|
}
|
|
}
|
|
else if(strategy == LFS_MINSUM)
|
|
{
|
|
/*adaptive filtering*/
|
|
size_t sum[5];
|
|
ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
|
|
size_t smallest = 0;
|
|
unsigned char type, bestType = 0;
|
|
|
|
for(type = 0; type != 5; ++type)
|
|
{
|
|
ucvector_init(&attempt[type]);
|
|
if(!ucvector_resize(&attempt[type], linebytes)) return 83; /*alloc fail*/
|
|
}
|
|
|
|
if(!error)
|
|
{
|
|
for(y = 0; y != h; ++y)
|
|
{
|
|
/*try the 5 filter types*/
|
|
for(type = 0; type != 5; ++type)
|
|
{
|
|
filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
|
|
|
|
/*calculate the sum of the result*/
|
|
sum[type] = 0;
|
|
if(type == 0)
|
|
{
|
|
for(x = 0; x != linebytes; ++x) sum[type] += (unsigned char)(attempt[type].data[x]);
|
|
}
|
|
else
|
|
{
|
|
for(x = 0; x != linebytes; ++x)
|
|
{
|
|
/*For differences, each byte should be treated as signed, values above 127 are negative
|
|
(converted to signed char). Filtertype 0 isn't a difference though, so use unsigned there.
|
|
This means filtertype 0 is almost never chosen, but that is justified.*/
|
|
unsigned char s = attempt[type].data[x];
|
|
sum[type] += s < 128 ? s : (255U - s);
|
|
}
|
|
}
|
|
|
|
/*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/
|
|
if(type == 0 || sum[type] < smallest)
|
|
{
|
|
bestType = type;
|
|
smallest = sum[type];
|
|
}
|
|
}
|
|
|
|
prevline = &in[y * linebytes];
|
|
|
|
/*now fill the out values*/
|
|
out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
|
|
for(x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
|
|
}
|
|
}
|
|
|
|
for(type = 0; type != 5; ++type) ucvector_cleanup(&attempt[type]);
|
|
}
|
|
else if(strategy == LFS_ENTROPY)
|
|
{
|
|
float sum[5];
|
|
ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
|
|
float smallest = 0;
|
|
unsigned type, bestType = 0;
|
|
unsigned count[256];
|
|
|
|
for(type = 0; type != 5; ++type)
|
|
{
|
|
ucvector_init(&attempt[type]);
|
|
if(!ucvector_resize(&attempt[type], linebytes)) return 83; /*alloc fail*/
|
|
}
|
|
|
|
for(y = 0; y != h; ++y)
|
|
{
|
|
/*try the 5 filter types*/
|
|
for(type = 0; type != 5; ++type)
|
|
{
|
|
filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
|
|
for(x = 0; x != 256; ++x) count[x] = 0;
|
|
for(x = 0; x != linebytes; ++x) ++count[attempt[type].data[x]];
|
|
++count[type]; /*the filter type itself is part of the scanline*/
|
|
sum[type] = 0;
|
|
for(x = 0; x != 256; ++x)
|
|
{
|
|
float p = count[x] / (float)(linebytes + 1);
|
|
sum[type] += count[x] == 0 ? 0 : flog2(1 / p) * p;
|
|
}
|
|
/*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/
|
|
if(type == 0 || sum[type] < smallest)
|
|
{
|
|
bestType = type;
|
|
smallest = sum[type];
|
|
}
|
|
}
|
|
|
|
prevline = &in[y * linebytes];
|
|
|
|
/*now fill the out values*/
|
|
out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
|
|
for(x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
|
|
}
|
|
|
|
for(type = 0; type != 5; ++type) ucvector_cleanup(&attempt[type]);
|
|
}
|
|
else if(strategy == LFS_PREDEFINED)
|
|
{
|
|
for(y = 0; y != h; ++y)
|
|
{
|
|
size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
|
|
size_t inindex = linebytes * y;
|
|
unsigned char type = settings->predefined_filters[y];
|
|
out[outindex] = type; /*filter type byte*/
|
|
filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, type);
|
|
prevline = &in[inindex];
|
|
}
|
|
}
|
|
else if(strategy == LFS_BRUTE_FORCE)
|
|
{
|
|
/*brute force filter chooser.
|
|
deflate the scanline after every filter attempt to see which one deflates best.
|
|
This is very slow and gives only slightly smaller, sometimes even larger, result*/
|
|
size_t size[5];
|
|
ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
|
|
size_t smallest = 0;
|
|
unsigned type = 0, bestType = 0;
|
|
unsigned char* dummy;
|
|
LodePNGCompressSettings zlibsettings = settings->zlibsettings;
|
|
/*use fixed tree on the attempts so that the tree is not adapted to the filtertype on purpose,
|
|
to simulate the true case where the tree is the same for the whole image. Sometimes it gives
|
|
better result with dynamic tree anyway. Using the fixed tree sometimes gives worse, but in rare
|
|
cases better compression. It does make this a bit less slow, so it's worth doing this.*/
|
|
zlibsettings.btype = 1;
|
|
/*a custom encoder likely doesn't read the btype setting and is optimized for complete PNG
|
|
images only, so disable it*/
|
|
zlibsettings.custom_zlib = 0;
|
|
zlibsettings.custom_deflate = 0;
|
|
for(type = 0; type != 5; ++type)
|
|
{
|
|
ucvector_init(&attempt[type]);
|
|
ucvector_resize(&attempt[type], linebytes); /*todo: give error if resize failed*/
|
|
}
|
|
for(y = 0; y != h; ++y) /*try the 5 filter types*/
|
|
{
|
|
for(type = 0; type != 5; ++type)
|
|
{
|
|
unsigned testsize = attempt[type].size;
|
|
/*if(testsize > 8) testsize /= 8;*/ /*it already works good enough by testing a part of the row*/
|
|
|
|
filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
|
|
size[type] = 0;
|
|
dummy = 0;
|
|
zlib_compress(&dummy, &size[type], attempt[type].data, testsize, &zlibsettings);
|
|
lodepng_free(dummy);
|
|
/*check if this is smallest size (or if type == 0 it's the first case so always store the values)*/
|
|
if(type == 0 || size[type] < smallest)
|
|
{
|
|
bestType = type;
|
|
smallest = size[type];
|
|
}
|
|
}
|
|
prevline = &in[y * linebytes];
|
|
out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
|
|
for(x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
|
|
}
|
|
for(type = 0; type != 5; ++type) ucvector_cleanup(&attempt[type]);
|
|
}
|
|
else return 88; /* unknown filter strategy */
|
|
|
|
return error;
|
|
}
|
|
|
|
static void addPaddingBits(unsigned char* out, const unsigned char* in,
|
|
size_t olinebits, size_t ilinebits, unsigned h)
|
|
{
|
|
/*The opposite of the removePaddingBits function
|
|
olinebits must be >= ilinebits*/
|
|
unsigned y;
|
|
size_t diff = olinebits - ilinebits;
|
|
size_t obp = 0, ibp = 0; /*bit pointers*/
|
|
for(y = 0; y != h; ++y)
|
|
{
|
|
size_t x;
|
|
for(x = 0; x < ilinebits; ++x)
|
|
{
|
|
unsigned char bit = readBitFromReversedStream(&ibp, in);
|
|
setBitOfReversedStream(&obp, out, bit);
|
|
}
|
|
/*obp += diff; --> no, fill in some value in the padding bits too, to avoid
|
|
"Use of uninitialised value of size ###" warning from valgrind*/
|
|
for(x = 0; x != diff; ++x) setBitOfReversedStream(&obp, out, 0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
in: non-interlaced image with size w*h
|
|
out: the same pixels, but re-ordered according to PNG's Adam7 interlacing, with
|
|
no padding bits between scanlines, but between reduced images so that each
|
|
reduced image starts at a byte.
|
|
bpp: bits per pixel
|
|
there are no padding bits, not between scanlines, not between reduced images
|
|
in has the following size in bits: w * h * bpp.
|
|
out is possibly bigger due to padding bits between reduced images
|
|
NOTE: comments about padding bits are only relevant if bpp < 8
|
|
*/
|
|
static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
|
|
{
|
|
unsigned passw[7], passh[7];
|
|
size_t filter_passstart[8], padded_passstart[8], passstart[8];
|
|
unsigned i;
|
|
|
|
Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
|
|
|
|
if(bpp >= 8)
|
|
{
|
|
for(i = 0; i != 7; ++i)
|
|
{
|
|
unsigned x, y, b;
|
|
size_t bytewidth = bpp / 8;
|
|
for(y = 0; y < passh[i]; ++y)
|
|
for(x = 0; x < passw[i]; ++x)
|
|
{
|
|
size_t pixelinstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth;
|
|
size_t pixeloutstart = passstart[i] + (y * passw[i] + x) * bytewidth;
|
|
for(b = 0; b < bytewidth; ++b)
|
|
{
|
|
out[pixeloutstart + b] = in[pixelinstart + b];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/
|
|
{
|
|
for(i = 0; i != 7; ++i)
|
|
{
|
|
unsigned x, y, b;
|
|
unsigned ilinebits = bpp * passw[i];
|
|
unsigned olinebits = bpp * w;
|
|
size_t obp, ibp; /*bit pointers (for out and in buffer)*/
|
|
for(y = 0; y < passh[i]; ++y)
|
|
for(x = 0; x < passw[i]; ++x)
|
|
{
|
|
ibp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp;
|
|
obp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
|
|
for(b = 0; b < bpp; ++b)
|
|
{
|
|
unsigned char bit = readBitFromReversedStream(&ibp, in);
|
|
setBitOfReversedStream(&obp, out, bit);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*out must be buffer big enough to contain uncompressed IDAT chunk data, and in must contain the full image.
|
|
return value is error**/
|
|
static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const unsigned char* in,
|
|
unsigned w, unsigned h,
|
|
const LodePNGInfo* info_png, const LodePNGEncoderSettings* settings)
|
|
{
|
|
/*
|
|
This function converts the pure 2D image with the PNG's colortype, into filtered-padded-interlaced data. Steps:
|
|
*) if no Adam7: 1) add padding bits (= posible extra bits per scanline if bpp < 8) 2) filter
|
|
*) if adam7: 1) Adam7_interlace 2) 7x add padding bits 3) 7x filter
|
|
*/
|
|
unsigned bpp = lodepng_get_bpp(&info_png->color);
|
|
unsigned error = 0;
|
|
|
|
if(info_png->interlace_method == 0)
|
|
{
|
|
*outsize = h + (h * ((w * bpp + 7) / 8)); /*image size plus an extra byte per scanline + possible padding bits*/
|
|
*out = (unsigned char*)lodepng_malloc(*outsize);
|
|
if(!(*out) && (*outsize)) error = 83; /*alloc fail*/
|
|
|
|
if(!error)
|
|
{
|
|
/*non multiple of 8 bits per scanline, padding bits needed per scanline*/
|
|
if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8)
|
|
{
|
|
unsigned char* padded = (unsigned char*)lodepng_malloc(h * ((w * bpp + 7) / 8));
|
|
if(!padded) error = 83; /*alloc fail*/
|
|
if(!error)
|
|
{
|
|
addPaddingBits(padded, in, ((w * bpp + 7) / 8) * 8, w * bpp, h);
|
|
error = filter(*out, padded, w, h, &info_png->color, settings);
|
|
}
|
|
lodepng_free(padded);
|
|
}
|
|
else
|
|
{
|
|
/*we can immediatly filter into the out buffer, no other steps needed*/
|
|
error = filter(*out, in, w, h, &info_png->color, settings);
|
|
}
|
|
}
|
|
}
|
|
else /*interlace_method is 1 (Adam7)*/
|
|
{
|
|
unsigned passw[7], passh[7];
|
|
size_t filter_passstart[8], padded_passstart[8], passstart[8];
|
|
unsigned char* adam7;
|
|
|
|
Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
|
|
|
|
*outsize = filter_passstart[7]; /*image size plus an extra byte per scanline + possible padding bits*/
|
|
*out = (unsigned char*)lodepng_malloc(*outsize);
|
|
if(!(*out)) error = 83; /*alloc fail*/
|
|
|
|
adam7 = (unsigned char*)lodepng_malloc(passstart[7]);
|
|
if(!adam7 && passstart[7]) error = 83; /*alloc fail*/
|
|
|
|
if(!error)
|
|
{
|
|
unsigned i;
|
|
|
|
Adam7_interlace(adam7, in, w, h, bpp);
|
|
for(i = 0; i != 7; ++i)
|
|
{
|
|
if(bpp < 8)
|
|
{
|
|
unsigned char* padded = (unsigned char*)lodepng_malloc(padded_passstart[i + 1] - padded_passstart[i]);
|
|
if(!padded) ERROR_BREAK(83); /*alloc fail*/
|
|
addPaddingBits(padded, &adam7[passstart[i]],
|
|
((passw[i] * bpp + 7) / 8) * 8, passw[i] * bpp, passh[i]);
|
|
error = filter(&(*out)[filter_passstart[i]], padded,
|
|
passw[i], passh[i], &info_png->color, settings);
|
|
lodepng_free(padded);
|
|
}
|
|
else
|
|
{
|
|
error = filter(&(*out)[filter_passstart[i]], &adam7[padded_passstart[i]],
|
|
passw[i], passh[i], &info_png->color, settings);
|
|
}
|
|
|
|
if(error) break;
|
|
}
|
|
}
|
|
|
|
lodepng_free(adam7);
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
palette must have 4 * palettesize bytes allocated, and given in format RGBARGBARGBARGBA...
|
|
returns 0 if the palette is opaque,
|
|
returns 1 if the palette has a single color with alpha 0 ==> color key
|
|
returns 2 if the palette is semi-translucent.
|
|
*/
|
|
static unsigned getPaletteTranslucency(const unsigned char* palette, size_t palettesize)
|
|
{
|
|
size_t i;
|
|
unsigned key = 0;
|
|
unsigned r = 0, g = 0, b = 0; /*the value of the color with alpha 0, so long as color keying is possible*/
|
|
for(i = 0; i != palettesize; ++i)
|
|
{
|
|
if(!key && palette[4 * i + 3] == 0)
|
|
{
|
|
r = palette[4 * i + 0]; g = palette[4 * i + 1]; b = palette[4 * i + 2];
|
|
key = 1;
|
|
i = (size_t)(-1); /*restart from beginning, to detect earlier opaque colors with key's value*/
|
|
}
|
|
else if(palette[4 * i + 3] != 255) return 2;
|
|
/*when key, no opaque RGB may have key's RGB*/
|
|
else if(key && r == palette[i * 4 + 0] && g == palette[i * 4 + 1] && b == palette[i * 4 + 2]) return 2;
|
|
}
|
|
return key;
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize)
|
|
{
|
|
unsigned char* inchunk = data;
|
|
while((size_t)(inchunk - data) < datasize)
|
|
{
|
|
CERROR_TRY_RETURN(lodepng_chunk_append(&out->data, &out->size, inchunk));
|
|
out->allocsize = out->size; /*fix the allocsize again*/
|
|
inchunk = lodepng_chunk_next(inchunk);
|
|
}
|
|
return 0;
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
|
|
unsigned lodepng_encode(unsigned char** out, size_t* outsize,
|
|
const unsigned char* image, unsigned w, unsigned h,
|
|
LodePNGState* state)
|
|
{
|
|
LodePNGInfo info;
|
|
ucvector outv;
|
|
unsigned char* data = 0; /*uncompressed version of the IDAT chunk data*/
|
|
size_t datasize = 0;
|
|
|
|
/*provide some proper output values if error will happen*/
|
|
*out = 0;
|
|
*outsize = 0;
|
|
state->error = 0;
|
|
|
|
lodepng_info_init(&info);
|
|
lodepng_info_copy(&info, &state->info_png);
|
|
|
|
if((info.color.colortype == LCT_PALETTE || state->encoder.force_palette)
|
|
&& (info.color.palettesize == 0 || info.color.palettesize > 256))
|
|
{
|
|
state->error = 68; /*invalid palette size, it is only allowed to be 1-256*/
|
|
return state->error;
|
|
}
|
|
|
|
if(state->encoder.auto_convert)
|
|
{
|
|
state->error = lodepng_auto_choose_color(&info.color, image, w, h, &state->info_raw);
|
|
}
|
|
if(state->error) return state->error;
|
|
|
|
if(state->encoder.zlibsettings.btype > 2)
|
|
{
|
|
CERROR_RETURN_ERROR(state->error, 61); /*error: unexisting btype*/
|
|
}
|
|
if(state->info_png.interlace_method > 1)
|
|
{
|
|
CERROR_RETURN_ERROR(state->error, 71); /*error: unexisting interlace mode*/
|
|
}
|
|
|
|
state->error = checkColorValidity(info.color.colortype, info.color.bitdepth);
|
|
if(state->error) return state->error; /*error: unexisting color type given*/
|
|
state->error = checkColorValidity(state->info_raw.colortype, state->info_raw.bitdepth);
|
|
if(state->error) return state->error; /*error: unexisting color type given*/
|
|
|
|
if(!lodepng_color_mode_equal(&state->info_raw, &info.color))
|
|
{
|
|
unsigned char* converted;
|
|
size_t size = (w * h * lodepng_get_bpp(&info.color) + 7) / 8;
|
|
|
|
converted = (unsigned char*)lodepng_malloc(size);
|
|
if(!converted && size) state->error = 83; /*alloc fail*/
|
|
if(!state->error)
|
|
{
|
|
state->error = lodepng_convert(converted, image, &info.color, &state->info_raw, w, h);
|
|
}
|
|
if(!state->error) preProcessScanlines(&data, &datasize, converted, w, h, &info, &state->encoder);
|
|
lodepng_free(converted);
|
|
}
|
|
else preProcessScanlines(&data, &datasize, image, w, h, &info, &state->encoder);
|
|
|
|
ucvector_init(&outv);
|
|
while(!state->error) /*while only executed once, to break on error*/
|
|
{
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
size_t i;
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
/*write signature and chunks*/
|
|
writeSignature(&outv);
|
|
/*IHDR*/
|
|
addChunk_IHDR(&outv, w, h, info.color.colortype, info.color.bitdepth, info.interlace_method);
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
/*unknown chunks between IHDR and PLTE*/
|
|
if(info.unknown_chunks_data[0])
|
|
{
|
|
state->error = addUnknownChunks(&outv, info.unknown_chunks_data[0], info.unknown_chunks_size[0]);
|
|
if(state->error) break;
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
/*PLTE*/
|
|
if(info.color.colortype == LCT_PALETTE)
|
|
{
|
|
addChunk_PLTE(&outv, &info.color);
|
|
}
|
|
if(state->encoder.force_palette && (info.color.colortype == LCT_RGB || info.color.colortype == LCT_RGBA))
|
|
{
|
|
addChunk_PLTE(&outv, &info.color);
|
|
}
|
|
/*tRNS*/
|
|
if(info.color.colortype == LCT_PALETTE && getPaletteTranslucency(info.color.palette, info.color.palettesize) != 0)
|
|
{
|
|
addChunk_tRNS(&outv, &info.color);
|
|
}
|
|
if((info.color.colortype == LCT_GREY || info.color.colortype == LCT_RGB) && info.color.key_defined)
|
|
{
|
|
addChunk_tRNS(&outv, &info.color);
|
|
}
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
/*bKGD (must come between PLTE and the IDAt chunks*/
|
|
if(info.background_defined) addChunk_bKGD(&outv, &info);
|
|
/*pHYs (must come before the IDAT chunks)*/
|
|
if(info.phys_defined) addChunk_pHYs(&outv, &info);
|
|
|
|
/*unknown chunks between PLTE and IDAT*/
|
|
if(info.unknown_chunks_data[1])
|
|
{
|
|
state->error = addUnknownChunks(&outv, info.unknown_chunks_data[1], info.unknown_chunks_size[1]);
|
|
if(state->error) break;
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
/*IDAT (multiple IDAT chunks must be consecutive)*/
|
|
state->error = addChunk_IDAT(&outv, data, datasize, &state->encoder.zlibsettings);
|
|
if(state->error) break;
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
/*tIME*/
|
|
if(info.time_defined) addChunk_tIME(&outv, &info.time);
|
|
/*tEXt and/or zTXt*/
|
|
for(i = 0; i != info.text_num; ++i)
|
|
{
|
|
if(strlen(info.text_keys[i]) > 79)
|
|
{
|
|
state->error = 66; /*text chunk too large*/
|
|
break;
|
|
}
|
|
if(strlen(info.text_keys[i]) < 1)
|
|
{
|
|
state->error = 67; /*text chunk too small*/
|
|
break;
|
|
}
|
|
if(state->encoder.text_compression)
|
|
{
|
|
addChunk_zTXt(&outv, info.text_keys[i], info.text_strings[i], &state->encoder.zlibsettings);
|
|
}
|
|
else
|
|
{
|
|
addChunk_tEXt(&outv, info.text_keys[i], info.text_strings[i]);
|
|
}
|
|
}
|
|
/*LodePNG version id in text chunk*/
|
|
if(state->encoder.add_id)
|
|
{
|
|
unsigned alread_added_id_text = 0;
|
|
for(i = 0; i != info.text_num; ++i)
|
|
{
|
|
if(!strcmp(info.text_keys[i], "LodePNG"))
|
|
{
|
|
alread_added_id_text = 1;
|
|
break;
|
|
}
|
|
}
|
|
if(alread_added_id_text == 0)
|
|
{
|
|
addChunk_tEXt(&outv, "LodePNG", LODEPNG_VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/
|
|
}
|
|
}
|
|
/*iTXt*/
|
|
for(i = 0; i != info.itext_num; ++i)
|
|
{
|
|
if(strlen(info.itext_keys[i]) > 79)
|
|
{
|
|
state->error = 66; /*text chunk too large*/
|
|
break;
|
|
}
|
|
if(strlen(info.itext_keys[i]) < 1)
|
|
{
|
|
state->error = 67; /*text chunk too small*/
|
|
break;
|
|
}
|
|
addChunk_iTXt(&outv, state->encoder.text_compression,
|
|
info.itext_keys[i], info.itext_langtags[i], info.itext_transkeys[i], info.itext_strings[i],
|
|
&state->encoder.zlibsettings);
|
|
}
|
|
|
|
/*unknown chunks between IDAT and IEND*/
|
|
if(info.unknown_chunks_data[2])
|
|
{
|
|
state->error = addUnknownChunks(&outv, info.unknown_chunks_data[2], info.unknown_chunks_size[2]);
|
|
if(state->error) break;
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
addChunk_IEND(&outv);
|
|
|
|
break; /*this isn't really a while loop; no error happened so break out now!*/
|
|
}
|
|
|
|
lodepng_info_cleanup(&info);
|
|
lodepng_free(data);
|
|
/*instead of cleaning the vector up, give it to the output*/
|
|
*out = outv.data;
|
|
*outsize = outv.size;
|
|
|
|
return state->error;
|
|
}
|
|
|
|
unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize, const unsigned char* image,
|
|
unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth)
|
|
{
|
|
unsigned error;
|
|
LodePNGState state;
|
|
lodepng_state_init(&state);
|
|
state.info_raw.colortype = colortype;
|
|
state.info_raw.bitdepth = bitdepth;
|
|
state.info_png.color.colortype = colortype;
|
|
state.info_png.color.bitdepth = bitdepth;
|
|
lodepng_encode(out, outsize, image, w, h, &state);
|
|
error = state.error;
|
|
lodepng_state_cleanup(&state);
|
|
return error;
|
|
}
|
|
|
|
unsigned lodepng_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
|
|
{
|
|
return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGBA, 8);
|
|
}
|
|
|
|
unsigned lodepng_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
|
|
{
|
|
return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGB, 8);
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_DISK
|
|
unsigned lodepng_encode_file(const char* filename, const unsigned char* image, unsigned w, unsigned h,
|
|
LodePNGColorType colortype, unsigned bitdepth)
|
|
{
|
|
unsigned char* buffer;
|
|
size_t buffersize;
|
|
unsigned error = lodepng_encode_memory(&buffer, &buffersize, image, w, h, colortype, bitdepth);
|
|
if(!error) error = lodepng_save_file(buffer, buffersize, filename);
|
|
lodepng_free(buffer);
|
|
return error;
|
|
}
|
|
|
|
unsigned lodepng_encode32_file(const char* filename, const unsigned char* image, unsigned w, unsigned h)
|
|
{
|
|
return lodepng_encode_file(filename, image, w, h, LCT_RGBA, 8);
|
|
}
|
|
|
|
unsigned lodepng_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h)
|
|
{
|
|
return lodepng_encode_file(filename, image, w, h, LCT_RGB, 8);
|
|
}
|
|
#endif /*LODEPNG_COMPILE_DISK*/
|
|
|
|
void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings)
|
|
{
|
|
lodepng_compress_settings_init(&settings->zlibsettings);
|
|
settings->filter_palette_zero = 1;
|
|
settings->filter_strategy = LFS_MINSUM;
|
|
settings->auto_convert = 1;
|
|
settings->force_palette = 0;
|
|
settings->predefined_filters = 0;
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
settings->add_id = 0;
|
|
settings->text_compression = 1;
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
}
|
|
|
|
#endif /*LODEPNG_COMPILE_ENCODER*/
|
|
#endif /*LODEPNG_COMPILE_PNG*/
|
|
|
|
#ifdef LODEPNG_COMPILE_ERROR_TEXT
|
|
/*
|
|
This returns the description of a numerical error code in English. This is also
|
|
the documentation of all the error codes.
|
|
*/
|
|
const char* lodepng_error_text(unsigned code)
|
|
{
|
|
switch(code)
|
|
{
|
|
case 0: return "no error, everything went ok";
|
|
case 1: return "nothing done yet"; /*the Encoder/Decoder has done nothing yet, error checking makes no sense yet*/
|
|
case 10: return "end of input memory reached without huffman end code"; /*while huffman decoding*/
|
|
case 11: return "error in code tree made it jump outside of huffman tree"; /*while huffman decoding*/
|
|
case 13: return "problem while processing dynamic deflate block";
|
|
case 14: return "problem while processing dynamic deflate block";
|
|
case 15: return "problem while processing dynamic deflate block";
|
|
case 16: return "unexisting code while processing dynamic deflate block";
|
|
case 17: return "end of out buffer memory reached while inflating";
|
|
case 18: return "invalid distance code while inflating";
|
|
case 19: return "end of out buffer memory reached while inflating";
|
|
case 20: return "invalid deflate block BTYPE encountered while decoding";
|
|
case 21: return "NLEN is not ones complement of LEN in a deflate block";
|
|
/*end of out buffer memory reached while inflating:
|
|
This can happen if the inflated deflate data is longer than the amount of bytes required to fill up
|
|
all the pixels of the image, given the color depth and image dimensions. Something that doesn't
|
|
happen in a normal, well encoded, PNG image.*/
|
|
case 22: return "end of out buffer memory reached while inflating";
|
|
case 23: return "end of in buffer memory reached while inflating";
|
|
case 24: return "invalid FCHECK in zlib header";
|
|
case 25: return "invalid compression method in zlib header";
|
|
case 26: return "FDICT encountered in zlib header while it's not used for PNG";
|
|
case 27: return "PNG file is smaller than a PNG header";
|
|
/*Checks the magic file header, the first 8 bytes of the PNG file*/
|
|
case 28: return "incorrect PNG signature, it's no PNG or corrupted";
|
|
case 29: return "first chunk is not the header chunk";
|
|
case 30: return "chunk length too large, chunk broken off at end of file";
|
|
case 31: return "illegal PNG color type or bpp";
|
|
case 32: return "illegal PNG compression method";
|
|
case 33: return "illegal PNG filter method";
|
|
case 34: return "illegal PNG interlace method";
|
|
case 35: return "chunk length of a chunk is too large or the chunk too small";
|
|
case 36: return "illegal PNG filter type encountered";
|
|
case 37: return "illegal bit depth for this color type given";
|
|
case 38: return "the palette is too big"; /*more than 256 colors*/
|
|
case 39: return "more palette alpha values given in tRNS chunk than there are colors in the palette";
|
|
case 40: return "tRNS chunk has wrong size for greyscale image";
|
|
case 41: return "tRNS chunk has wrong size for RGB image";
|
|
case 42: return "tRNS chunk appeared while it was not allowed for this color type";
|
|
case 43: return "bKGD chunk has wrong size for palette image";
|
|
case 44: return "bKGD chunk has wrong size for greyscale image";
|
|
case 45: return "bKGD chunk has wrong size for RGB image";
|
|
/*the input data is empty, maybe a PNG file doesn't exist or is in the wrong path*/
|
|
case 48: return "empty input or file doesn't exist";
|
|
case 49: return "jumped past memory while generating dynamic huffman tree";
|
|
case 50: return "jumped past memory while generating dynamic huffman tree";
|
|
case 51: return "jumped past memory while inflating huffman block";
|
|
case 52: return "jumped past memory while inflating";
|
|
case 53: return "size of zlib data too small";
|
|
case 54: return "repeat symbol in tree while there was no value symbol yet";
|
|
/*jumped past tree while generating huffman tree, this could be when the
|
|
tree will have more leaves than symbols after generating it out of the
|
|
given lenghts. They call this an oversubscribed dynamic bit lengths tree in zlib.*/
|
|
case 55: return "jumped past tree while generating huffman tree";
|
|
case 56: return "given output image colortype or bitdepth not supported for color conversion";
|
|
case 57: return "invalid CRC encountered (checking CRC can be disabled)";
|
|
case 58: return "invalid ADLER32 encountered (checking ADLER32 can be disabled)";
|
|
case 59: return "requested color conversion not supported";
|
|
case 60: return "invalid window size given in the settings of the encoder (must be 0-32768)";
|
|
case 61: return "invalid BTYPE given in the settings of the encoder (only 0, 1 and 2 are allowed)";
|
|
/*LodePNG leaves the choice of RGB to greyscale conversion formula to the user.*/
|
|
case 62: return "conversion from color to greyscale not supported";
|
|
case 63: return "length of a chunk too long, max allowed for PNG is 2147483647 bytes per chunk"; /*(2^31-1)*/
|
|
/*this would result in the inability of a deflated block to ever contain an end code. It must be at least 1.*/
|
|
case 64: return "the length of the END symbol 256 in the Huffman tree is 0";
|
|
case 66: return "the length of a text chunk keyword given to the encoder is longer than the maximum of 79 bytes";
|
|
case 67: return "the length of a text chunk keyword given to the encoder is smaller than the minimum of 1 byte";
|
|
case 68: return "tried to encode a PLTE chunk with a palette that has less than 1 or more than 256 colors";
|
|
case 69: return "unknown chunk type with 'critical' flag encountered by the decoder";
|
|
case 71: return "unexisting interlace mode given to encoder (must be 0 or 1)";
|
|
case 72: return "while decoding, unexisting compression method encountering in zTXt or iTXt chunk (it must be 0)";
|
|
case 73: return "invalid tIME chunk size";
|
|
case 74: return "invalid pHYs chunk size";
|
|
/*length could be wrong, or data chopped off*/
|
|
case 75: return "no null termination char found while decoding text chunk";
|
|
case 76: return "iTXt chunk too short to contain required bytes";
|
|
case 77: return "integer overflow in buffer size";
|
|
case 78: return "failed to open file for reading"; /*file doesn't exist or couldn't be opened for reading*/
|
|
case 79: return "failed to open file for writing";
|
|
case 80: return "tried creating a tree of 0 symbols";
|
|
case 81: return "lazy matching at pos 0 is impossible";
|
|
case 82: return "color conversion to palette requested while a color isn't in palette";
|
|
case 83: return "memory allocation failed";
|
|
case 84: return "given image too small to contain all pixels to be encoded";
|
|
case 86: return "impossible offset in lz77 encoding (internal bug)";
|
|
case 87: return "must provide custom zlib function pointer if LODEPNG_COMPILE_ZLIB is not defined";
|
|
case 88: return "invalid filter strategy given for LodePNGEncoderSettings.filter_strategy";
|
|
case 89: return "text chunk keyword too short or long: must have size 1-79";
|
|
/*the windowsize in the LodePNGCompressSettings. Requiring POT(==> & instead of %) makes encoding 12% faster.*/
|
|
case 90: return "windowsize must be a power of two";
|
|
case 91: return "invalid decompressed idat size";
|
|
case 92: return "too many pixels, not supported";
|
|
case 93: return "zero width or height is invalid";
|
|
}
|
|
return "unknown error code";
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ERROR_TEXT*/
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* // C++ Wrapper // */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
#ifdef LODEPNG_COMPILE_CPP
|
|
namespace lodepng
|
|
{
|
|
|
|
#ifdef LODEPNG_COMPILE_DISK
|
|
void load_file(std::vector<unsigned char>& buffer, const std::string& filename)
|
|
{
|
|
std::ifstream file(filename.c_str(), std::ios::in|std::ios::binary|std::ios::ate);
|
|
|
|
/*get filesize*/
|
|
std::streamsize size = 0;
|
|
if(file.seekg(0, std::ios::end).good()) size = file.tellg();
|
|
if(file.seekg(0, std::ios::beg).good()) size -= file.tellg();
|
|
|
|
/*read contents of the file into the vector*/
|
|
buffer.resize(size_t(size));
|
|
if(size > 0) file.read((char*)(&buffer[0]), size);
|
|
}
|
|
|
|
/*write given buffer to the file, overwriting the file, it doesn't append to it.*/
|
|
void save_file(const std::vector<unsigned char>& buffer, const std::string& filename)
|
|
{
|
|
std::ofstream file(filename.c_str(), std::ios::out|std::ios::binary);
|
|
file.write(buffer.empty() ? 0 : (char*)&buffer[0], std::streamsize(buffer.size()));
|
|
}
|
|
#endif /* LODEPNG_COMPILE_DISK */
|
|
|
|
#ifdef LODEPNG_COMPILE_ZLIB
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
|
|
const LodePNGDecompressSettings& settings)
|
|
{
|
|
unsigned char* buffer = 0;
|
|
size_t buffersize = 0;
|
|
unsigned error = zlib_decompress(&buffer, &buffersize, in, insize, &settings);
|
|
if(buffer)
|
|
{
|
|
out.insert(out.end(), &buffer[0], &buffer[buffersize]);
|
|
lodepng_free(buffer);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
|
|
const LodePNGDecompressSettings& settings)
|
|
{
|
|
return decompress(out, in.empty() ? 0 : &in[0], in.size(), settings);
|
|
}
|
|
#endif /* LODEPNG_COMPILE_DECODER */
|
|
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
|
|
const LodePNGCompressSettings& settings)
|
|
{
|
|
unsigned char* buffer = 0;
|
|
size_t buffersize = 0;
|
|
unsigned error = zlib_compress(&buffer, &buffersize, in, insize, &settings);
|
|
if(buffer)
|
|
{
|
|
out.insert(out.end(), &buffer[0], &buffer[buffersize]);
|
|
lodepng_free(buffer);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
|
|
const LodePNGCompressSettings& settings)
|
|
{
|
|
return compress(out, in.empty() ? 0 : &in[0], in.size(), settings);
|
|
}
|
|
#endif /* LODEPNG_COMPILE_ENCODER */
|
|
#endif /* LODEPNG_COMPILE_ZLIB */
|
|
|
|
|
|
#ifdef LODEPNG_COMPILE_PNG
|
|
|
|
State::State()
|
|
{
|
|
lodepng_state_init(this);
|
|
}
|
|
|
|
State::State(const State& other)
|
|
{
|
|
lodepng_state_init(this);
|
|
lodepng_state_copy(this, &other);
|
|
}
|
|
|
|
State::~State()
|
|
{
|
|
lodepng_state_cleanup(this);
|
|
}
|
|
|
|
State& State::operator=(const State& other)
|
|
{
|
|
lodepng_state_copy(this, &other);
|
|
return *this;
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
|
|
unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const unsigned char* in,
|
|
size_t insize, LodePNGColorType colortype, unsigned bitdepth)
|
|
{
|
|
unsigned char* buffer;
|
|
unsigned error = lodepng_decode_memory(&buffer, &w, &h, in, insize, colortype, bitdepth);
|
|
if(buffer && !error)
|
|
{
|
|
State state;
|
|
state.info_raw.colortype = colortype;
|
|
state.info_raw.bitdepth = bitdepth;
|
|
size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw);
|
|
out.insert(out.end(), &buffer[0], &buffer[buffersize]);
|
|
lodepng_free(buffer);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
|
|
const std::vector<unsigned char>& in, LodePNGColorType colortype, unsigned bitdepth)
|
|
{
|
|
return decode(out, w, h, in.empty() ? 0 : &in[0], (unsigned)in.size(), colortype, bitdepth);
|
|
}
|
|
|
|
unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
|
|
State& state,
|
|
const unsigned char* in, size_t insize)
|
|
{
|
|
unsigned char* buffer = NULL;
|
|
unsigned error = lodepng_decode(&buffer, &w, &h, &state, in, insize);
|
|
if(buffer && !error)
|
|
{
|
|
size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw);
|
|
out.insert(out.end(), &buffer[0], &buffer[buffersize]);
|
|
}
|
|
lodepng_free(buffer);
|
|
return error;
|
|
}
|
|
|
|
unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
|
|
State& state,
|
|
const std::vector<unsigned char>& in)
|
|
{
|
|
return decode(out, w, h, state, in.empty() ? 0 : &in[0], in.size());
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_DISK
|
|
unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const std::string& filename,
|
|
LodePNGColorType colortype, unsigned bitdepth)
|
|
{
|
|
std::vector<unsigned char> buffer;
|
|
load_file(buffer, filename);
|
|
return decode(out, w, h, buffer, colortype, bitdepth);
|
|
}
|
|
#endif /* LODEPNG_COMPILE_DECODER */
|
|
#endif /* LODEPNG_COMPILE_DISK */
|
|
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
unsigned encode(std::vector<unsigned char>& out, const unsigned char* in, unsigned w, unsigned h,
|
|
LodePNGColorType colortype, unsigned bitdepth)
|
|
{
|
|
unsigned char* buffer;
|
|
size_t buffersize;
|
|
unsigned error = lodepng_encode_memory(&buffer, &buffersize, in, w, h, colortype, bitdepth);
|
|
if(buffer)
|
|
{
|
|
out.insert(out.end(), &buffer[0], &buffer[buffersize]);
|
|
lodepng_free(buffer);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
unsigned encode(std::vector<unsigned char>& out,
|
|
const std::vector<unsigned char>& in, unsigned w, unsigned h,
|
|
LodePNGColorType colortype, unsigned bitdepth)
|
|
{
|
|
if(lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84;
|
|
return encode(out, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth);
|
|
}
|
|
|
|
unsigned encode(std::vector<unsigned char>& out,
|
|
const unsigned char* in, unsigned w, unsigned h,
|
|
State& state)
|
|
{
|
|
unsigned char* buffer;
|
|
size_t buffersize;
|
|
unsigned error = lodepng_encode(&buffer, &buffersize, in, w, h, &state);
|
|
if(buffer)
|
|
{
|
|
out.insert(out.end(), &buffer[0], &buffer[buffersize]);
|
|
lodepng_free(buffer);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
unsigned encode(std::vector<unsigned char>& out,
|
|
const std::vector<unsigned char>& in, unsigned w, unsigned h,
|
|
State& state)
|
|
{
|
|
if(lodepng_get_raw_size(w, h, &state.info_raw) > in.size()) return 84;
|
|
return encode(out, in.empty() ? 0 : &in[0], w, h, state);
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_DISK
|
|
unsigned encode(const std::string& filename,
|
|
const unsigned char* in, unsigned w, unsigned h,
|
|
LodePNGColorType colortype, unsigned bitdepth)
|
|
{
|
|
std::vector<unsigned char> buffer;
|
|
unsigned error = encode(buffer, in, w, h, colortype, bitdepth);
|
|
if(!error) save_file(buffer, filename);
|
|
return error;
|
|
}
|
|
|
|
unsigned encode(const std::string& filename,
|
|
const std::vector<unsigned char>& in, unsigned w, unsigned h,
|
|
LodePNGColorType colortype, unsigned bitdepth)
|
|
{
|
|
if(lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84;
|
|
return encode(filename, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth);
|
|
}
|
|
#endif /* LODEPNG_COMPILE_DISK */
|
|
#endif /* LODEPNG_COMPILE_ENCODER */
|
|
#endif /* LODEPNG_COMPILE_PNG */
|
|
} /* namespace lodepng */
|
|
#endif /*LODEPNG_COMPILE_CPP*/
|