libs/rt-thread
libs
/
rt-thread
4
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity
rt-thread/components/external/tjpgd1a/tjpgd.c

975 lines
34 KiB
C
Raw Normal View History

Re-normalizing the repo
2013-01-08 22:40:58 +08:00
/*----------------------------------------------------------------------------/
/ TJpgDec - Tiny JPEG Decompressor R0.01a (C)ChaN, 2012
/-----------------------------------------------------------------------------/
/ The TJpgDec is a generic JPEG decompressor module for tiny embedded systems.
/ This is a free software that opened for education, research and commercial
/ developments under license policy of following terms.
/
/ Copyright (C) 2012, ChaN, all right reserved.
/
/ * The TJpgDec module is a free software and there is NO WARRANTY.
/ * No restriction on use. You can use, modify and redistribute it for
/ personal, non-profit or commercial products UNDER YOUR RESPONSIBILITY.
/ * Redistributions of source code must retain the above copyright notice.
/
/-----------------------------------------------------------------------------/
/ Oct 04,'11 R0.01 First release.
/ Jan 25,'12 Modified by onelife
/ Feb 19,'12 R0.01a Fixed decompression fails when scan starts with an escape seq.
/----------------------------------------------------------------------------*/
#include "tjpgd.h"
/*-----------------------------------------------*/
/* Zigzag-order to raster-order conversion table */
/*-----------------------------------------------*/
#define ZIG(n) Zig[n]
static
const BYTE Zig[64] = { /* Zigzag-order to raster-order conversion table */
0, 1, 8, 16, 9, 2, 3, 10, 17, 24, 32, 25, 18, 11, 4, 5,
12, 19, 26, 33, 40, 48, 41, 34, 27, 20, 13, 6, 7, 14, 21, 28,
35, 42, 49, 56, 57, 50, 43, 36, 29, 22, 15, 23, 30, 37, 44, 51,
58, 59, 52, 45, 38, 31, 39, 46, 53, 60, 61, 54, 47, 55, 62, 63
};
/*-------------------------------------------------*/
/* Input scale factor of Arai algorithm */
/* (scaled up 16 bits for fixed point operations) */
/*-------------------------------------------------*/
#define IPSF(n) Ipsf[n]
static
const WORD Ipsf[64] = { /* See also aa_idct.png */
(WORD)(1.00000*8192), (WORD)(1.38704*8192), (WORD)(1.30656*8192), (WORD)(1.17588*8192), (WORD)(1.00000*8192), (WORD)(0.78570*8192), (WORD)(0.54120*8192), (WORD)(0.27590*8192),
(WORD)(1.38704*8192), (WORD)(1.92388*8192), (WORD)(1.81226*8192), (WORD)(1.63099*8192), (WORD)(1.38704*8192), (WORD)(1.08979*8192), (WORD)(0.75066*8192), (WORD)(0.38268*8192),
(WORD)(1.30656*8192), (WORD)(1.81226*8192), (WORD)(1.70711*8192), (WORD)(1.53636*8192), (WORD)(1.30656*8192), (WORD)(1.02656*8192), (WORD)(0.70711*8192), (WORD)(0.36048*8192),
(WORD)(1.17588*8192), (WORD)(1.63099*8192), (WORD)(1.53636*8192), (WORD)(1.38268*8192), (WORD)(1.17588*8192), (WORD)(0.92388*8192), (WORD)(0.63638*8192), (WORD)(0.32442*8192),
(WORD)(1.00000*8192), (WORD)(1.38704*8192), (WORD)(1.30656*8192), (WORD)(1.17588*8192), (WORD)(1.00000*8192), (WORD)(0.78570*8192), (WORD)(0.54120*8192), (WORD)(0.27590*8192),
(WORD)(0.78570*8192), (WORD)(1.08979*8192), (WORD)(1.02656*8192), (WORD)(0.92388*8192), (WORD)(0.78570*8192), (WORD)(0.61732*8192), (WORD)(0.42522*8192), (WORD)(0.21677*8192),
(WORD)(0.54120*8192), (WORD)(0.75066*8192), (WORD)(0.70711*8192), (WORD)(0.63638*8192), (WORD)(0.54120*8192), (WORD)(0.42522*8192), (WORD)(0.29290*8192), (WORD)(0.14932*8192),
(WORD)(0.27590*8192), (WORD)(0.38268*8192), (WORD)(0.36048*8192), (WORD)(0.32442*8192), (WORD)(0.27590*8192), (WORD)(0.21678*8192), (WORD)(0.14932*8192), (WORD)(0.07612*8192)
};
/*---------------------------------------------*/
/* Conversion table for fast clipping process */
/*---------------------------------------------*/
#define BYTECLIP(v) Clip8[(UINT)(v) & 0x3FF]
static
const BYTE Clip8[1024] = {
/* 0..255 */
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95,
96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127,
128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,
160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,
192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223,
224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255,
/* 256..511 */
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
/* -512..-257 */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* -256..-1 */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
/*-----------------------------------------------------------------------*/
/* Allocate a memory block from memory pool */
/*-----------------------------------------------------------------------*/
static
void* alloc_pool ( /* Pointer to allocated memory block (NULL:no memory available) */
JDEC* jd, /* Pointer to the decompressor object */
UINT nd /* Number of bytes to allocate */
)
{
char *rp = 0;
nd = (nd + 3) & ~3; /* Align block size to the word boundary */
if (jd->sz_pool >= nd) {
jd->sz_pool -= nd;
rp = (char*)jd->pool; /* Get start of available memory pool */
jd->pool = (void*)(rp + nd); /* Allocate requierd bytes */
}
return (void*)rp; /* Return allocated memory block (NULL:no memory to allocate) */
}
/*-----------------------------------------------------------------------*/
/* Create de-quantization and prescaling tables with a DQT segment */
/*-----------------------------------------------------------------------*/
static
UINT create_qt_tbl ( /* 0:OK, !0:Failed */
JDEC* jd, /* Pointer to the decompressor object */
const BYTE* data, /* Pointer to the quantizer tables */
UINT ndata /* Size of input data */
)
{
UINT i;
BYTE d, z;
LONG *pb;
while (ndata) { /* Process all tables in the segment */
if (ndata < 65) return JDR_FMT1; /* Err: table size is unaligned */
ndata -= 65;
d = *data++; /* Get table property */
if (d & 0xF0) return JDR_FMT1; /* Err: not 8-bit resolution */
i = d & 3; /* Get table ID */
pb = alloc_pool(jd, 64 * sizeof (LONG));/* Allocate a memory block for the table */
if (!pb) return JDR_MEM1; /* Err: not enough memory */
jd->qttbl[i] = pb; /* Register the table */
for (i = 0; i < 64; i++) { /* Load the table */
z = ZIG(i); /* Zigzag-order to raster-order conversion */
pb[z] = (LONG)((DWORD)*data++ * IPSF(z)); /* Apply scale factor of Arai algorithm to the de-quantizers */
}
}
return JDR_OK;
}
/*-----------------------------------------------------------------------*/
/* Create huffman code tables with a DHT segment */
/*-----------------------------------------------------------------------*/
static
UINT create_huffman_tbl ( /* 0:OK, !0:Failed */
JDEC* jd, /* Pointer to the decompressor object */
const BYTE* data, /* Pointer to the packed huffman tables */
UINT ndata /* Size of input data */
)
{
UINT i, j, b, np, cls, num;
BYTE d, *pb, *pd;
WORD hc, *ph;
while (ndata) { /* Process all tables in the segment */
if (ndata < 17) return JDR_FMT1; /* Err: wrong data size */
ndata -= 17;
d = *data++; /* Get table number and class */
cls = (d >> 4); num = d & 0x0F; /* class = dc(0)/ac(1), table number = 0/1 */
if (d & 0xEE) return JDR_FMT1; /* Err: invalid class/number */
pb = alloc_pool(jd, 16); /* Allocate a memory block for the bit distribution table */
if (!pb) return JDR_MEM1; /* Err: not enough memory */
jd->huffbits[num][cls] = pb;
for (np = i = 0; i < 16; i++) { /* Load number of patterns for 1 to 16-bit code */
pb[i] = b = *data++;
np += b; /* Get sum of code words for each code */
}
ph = alloc_pool(jd, np * sizeof (WORD));/* Allocate a memory block for the code word table */
if (!ph) return JDR_MEM1; /* Err: not enough memory */
jd->huffcode[num][cls] = ph;
hc = 0;
for (j = i = 0; i < 16; i++) { /* Re-build huffman code word table */
b = pb[i];
while (b--) ph[j++] = hc++;
hc <<= 1;
}
if (ndata < np) return JDR_FMT1; /* Err: wrong data size */
ndata -= np;
pd = alloc_pool(jd, np); /* Allocate a memory block for the decoded data */
if (!pd) return JDR_MEM1; /* Err: not enough memory */
jd->huffdata[num][cls] = pd;
for (i = 0; i < np; i++) { /* Load decoded data corresponds to each code ward */
d = *data++;
if (!cls && d > 11) return JDR_FMT1;
*pd++ = d;
}
}
return JDR_OK;
}
/*-----------------------------------------------------------------------*/
/* Extract N bits from input stream */
/*-----------------------------------------------------------------------*/
static
INT bitext ( /* >=0: extracted data, <0: error code */
JDEC* jd, /* Pointer to the decompressor object */
UINT nbit /* Number of bits to extract (1 to 11) */
)
{
BYTE msk, s, *dp;
UINT dc, v, f;
msk = jd->dmsk; dc = jd->dctr; dp = jd->dptr; /* Bit mask, number of data available, read ptr */
s = *dp; v = f = 0;
do {
if (!msk) { /* Next byte? */
if (!dc) { /* No input data is available, re-fill input buffer */
dp = jd->inbuf; /* Top of input buffer */
dc = jd->infunc(jd, dp, JD_SZBUF);
if (!dc) return 0 - JDR_INP; /* Err: read error or wrong stream termination */
} else {
dp++; /* Next data ptr */
}
dc--; /* Decrement number of available bytes */
if (f) { /* In flag sequence? */
f = 0; /* Exit flag sequence */
if (*dp != 0) return 0 - JDR_FMT1; /* Err: unexpected flag is detected (may be collapted data) */
*dp = s = 0xFF; /* The flag is a data 0xFF */
} else {
s = *dp; /* Get next data byte */
if (s == 0xFF) { /* Is start of flag sequence? */
f = 1; continue; /* Enter flag sequence */
}
}
msk = 0x80; /* Read from MSB */
}
v <<= 1; /* Get a bit */
if (s & msk) v++;
msk >>= 1;
nbit--;
} while (nbit);
jd->dmsk = msk; jd->dctr = dc; jd->dptr = dp;
return (INT)v;
}
/*-----------------------------------------------------------------------*/
/* Extract a huffman decoded data from input stream */
/*-----------------------------------------------------------------------*/
static
INT huffext ( /* >=0: decoded data, <0: error code */
JDEC* jd, /* Pointer to the decompressor object */
const BYTE* hbits, /* Pointer to the bit distribution table */
const WORD* hcode, /* Pointer to the code word table */
const BYTE* hdata /* Pointer to the data table */
)
{
BYTE msk, s, *dp;
UINT dc, v, f, bl, nd;
msk = jd->dmsk; dc = jd->dctr; dp = jd->dptr; /* Bit mask, number of data available, read ptr */
s = *dp; v = f = 0;
bl = 16; /* Max code length */
do {
if (!msk) { /* Next byte? */
if (!dc) { /* No input data is available, re-fill input buffer */
dp = jd->inbuf; /* Top of input buffer */
dc = jd->infunc(jd, dp, JD_SZBUF);
if (!dc) return 0 - JDR_INP; /* Err: read error or wrong stream termination */
} else {
dp++; /* Next data ptr */
}
dc--; /* Decrement number of available bytes */
if (f) { /* In flag sequence? */
f = 0; /* Exit flag sequence */
if (*dp != 0)
return 0 - JDR_FMT1;/* Err: unexpected flag is detected (may be collapted data) */
*dp = s = 0xFF; /* The flag is a data 0xFF */
} else {
s = *dp; /* Get next data byte */
if (s == 0xFF) { /* Is start of flag sequence? */
f = 1; continue; /* Enter flag sequence, get trailing byte */
}
}
msk = 0x80; /* Read from MSB */
}
v <<= 1; /* Get a bit */
if (s & msk) v++;
msk >>= 1;
for (nd = *hbits++; nd; nd--) { /* Search the code word in this bit length */
if (v == *hcode++) { /* Matched? */
jd->dmsk = msk; jd->dctr = dc; jd->dptr = dp;
return *hdata; /* Return the decoded data */
}
hdata++;
}
bl--;
} while (bl);
return 0 - JDR_FMT1; /* Err: code not found (may be collapted data) */
}
/*-----------------------------------------------------------------------*/
/* Apply Inverse-DCT in Arai Algorithm (see also aa_idct.png) */
/*-----------------------------------------------------------------------*/
static
void block_idct (
LONG* src, /* Input block data (de-quantized and pre-scaled for Arai Algorithm) */
BYTE* dst /* Pointer to the destination to store the block as byte array */
)
{
const LONG M13 = (LONG)(1.41421*4096), M2 = (LONG)(1.08239*4096), M4 = (LONG)(2.61313*4096), M5 = (LONG)(1.84776*4096);
LONG v0, v1, v2, v3, v4, v5, v6, v7;
LONG t10, t11, t12, t13;
UINT i;
/* Process columns */
for (i = 0; i < 8; i++) {
v0 = src[8 * 0]; /* Get even elements */
v1 = src[8 * 2];
v2 = src[8 * 4];
v3 = src[8 * 6];
t10 = v0 + v2; /* Process the even elements */
t12 = v0 - v2;
t11 = (v1 - v3) * M13 >> 12;
v3 += v1;
t11 -= v3;
v0 = t10 + v3;
v3 = t10 - v3;
v1 = t11 + t12;
v2 = t12 - t11;
v4 = src[8 * 7]; /* Get odd elements */
v5 = src[8 * 1];
v6 = src[8 * 5];
v7 = src[8 * 3];
t10 = v5 - v4; /* Process the odd elements */
t11 = v5 + v4;
t12 = v6 - v7;
v7 += v6;
v5 = (t11 - v7) * M13 >> 12;
v7 += t11;
t13 = (t10 + t12) * M5 >> 12;
v4 = t13 - (t10 * M2 >> 12);
v6 = t13 - (t12 * M4 >> 12) - v7;
v5 -= v6;
v4 -= v5;
src[8 * 0] = v0 + v7; /* Write-back transformed values */
src[8 * 7] = v0 - v7;
src[8 * 1] = v1 + v6;
src[8 * 6] = v1 - v6;
src[8 * 2] = v2 + v5;
src[8 * 5] = v2 - v5;
src[8 * 3] = v3 + v4;
src[8 * 4] = v3 - v4;
src++; /* Next column */
}
/* Process rows */
src -= 8;
for (i = 0; i < 8; i++) {
v0 = src[0] + (128L << 8); /* Get even elements (remove DC offset (-128) here) */
v1 = src[2];
v2 = src[4];
v3 = src[6];
t10 = v0 + v2; /* Process the even elements */
t12 = v0 - v2;
t11 = (v1 - v3) * M13 >> 12;
v3 += v1;
t11 -= v3;
v0 = t10 + v3;
v3 = t10 - v3;
v1 = t11 + t12;
v2 = t12 - t11;
v4 = src[7]; /* Get odd elements */
v5 = src[1];
v6 = src[5];
v7 = src[3];
t10 = v5 - v4; /* Process the odd elements */
t11 = v5 + v4;
t12 = v6 - v7;
v7 += v6;
v5 = (t11 - v7) * M13 >> 12;
v7 += t11;
t13 = (t10 + t12) * M5 >> 12;
v4 = t13 - (t10 * M2 >> 12);
v6 = t13 - (t12 * M4 >> 12) - v7;
v5 -= v6;
v4 -= v5;
dst[0] = BYTECLIP((v0 + v7) >> 8); /* Descale the transformed values 8 bits and output */
dst[7] = BYTECLIP((v0 - v7) >> 8);
dst[1] = BYTECLIP((v1 + v6) >> 8);
dst[6] = BYTECLIP((v1 - v6) >> 8);
dst[2] = BYTECLIP((v2 + v5) >> 8);
dst[5] = BYTECLIP((v2 - v5) >> 8);
dst[3] = BYTECLIP((v3 + v4) >> 8);
dst[4] = BYTECLIP((v3 - v4) >> 8);
dst += 8;
src += 8; /* Next row */
}
}
/*-----------------------------------------------------------------------*/
/* Load all blocks in the MCU into working buffer */
/*-----------------------------------------------------------------------*/
static
JRESULT mcu_load (
JDEC* jd /* Pointer to the decompressor object */
)
{
LONG *tmp = (LONG*)jd->workbuf; /* Block working buffer for de-quantize and IDCT */
UINT blk, nby, nbc, i, z, id, cmp;
INT b, d, e;
BYTE *bp;
const BYTE *hb, *hd;
const WORD *hc;
const LONG *dqf;
nby = jd->msx * jd->msy; /* Number of Y blocks (1, 2 or 4) */
nbc = 2; /* Number of C blocks (2) */
bp = jd->mcubuf; /* Pointer to the first block */
for (blk = 0; blk < nby + nbc; blk++) {
cmp = (blk < nby) ? 0 : blk - nby + 1; /* Component number 0:Y, 1:Cb, 2:Cr */
id = cmp ? 1 : 0; /* Huffman table ID of the component */
/* Extract a DC element from input stream */
hb = jd->huffbits[id][0]; /* Huffman table for the DC element */
hc = jd->huffcode[id][0];
hd = jd->huffdata[id][0];
b = huffext(jd, hb, hc, hd); /* Extract a huffman coded data (bit length) */
if (b < 0) return 0 - b; /* Err: invalid code or input */
d = jd->dcv[cmp]; /* DC value of previous block */
if (b) { /* If there is any difference from previous block */
e = bitext(jd, b); /* Extract data bits */
if (e < 0) return 0 - e; /* Err: input */
b = 1 << (b - 1); /* MSB position */
if (!(e & b)) e -= (b << 1) - 1; /* Restore sign if needed */
d += e; /* Get current value */
jd->dcv[cmp] = (SHORT)d; /* Save current DC value for next block */
}
dqf = jd->qttbl[jd->qtid[cmp]]; /* De-quantizer table ID for this component */
tmp[0] = d * dqf[0] >> 8; /* De-quantize, apply scale factor of Arai algorithm and descale 8 bits */
/* Extract following 63 AC elements from input stream */
for (i = 1; i < 64; i++) tmp[i] = 0; /* Clear rest of elements */
hb = jd->huffbits[id][1]; /* Huffman table for the AC elements */
hc = jd->huffcode[id][1];
hd = jd->huffdata[id][1];
i = 1; /* Top of the AC elements */
do {
b = huffext(jd, hb, hc, hd); /* Extract a huffman coded value (zero runs and bit length) */
if (b == 0) break; /* EOB? */
if (b < 0) return 0 - b; /* Err: invalid code or input error */
z = (UINT)b >> 4; /* Number of leading zero elements */
if (z) {
i += z; /* Skip zero elements */
if (i >= 64) return JDR_FMT1; /* Too long zero run */
}
if (b &= 0x0F) { /* Bit length */
d = bitext(jd, b); /* Extract data bits */
if (d < 0) return 0 - d; /* Err: input device */
b = 1 << (b - 1); /* MSB position */
if (!(d & b)) d -= (b << 1) - 1;/* Restore negative value if needed */
z = ZIG(i); /* Zigzag-order to raster-order converted index */
tmp[z] = d * dqf[z] >> 8; /* De-quantize, apply scale factor of Arai algorithm and descale 8 bits */
}
} while (++i < 64); /* Next AC element */
if (JD_USE_SCALE && jd->scale == 3)
*bp = (*tmp / 256) + 128; /* If scale ratio is 1/8, IDCT can be ommited and only DC element is used */
else
block_idct(tmp, bp); /* Apply IDCT and store the block to the MCU buffer */
bp += 64; /* Next block */
}
return JDR_OK; /* All blocks have been loaded successfully */
}
/*-----------------------------------------------------------------------*/
/* Output an MCU: Convert YCrCb to RGB and output it in RGB form */
/*-----------------------------------------------------------------------*/
static
JRESULT mcu_output (
JDEC* jd, /* Pointer to the decompressor object */
UINT (*outfunc)(JDEC*, void*, JRECT*), /* RGB output function */
UINT x, /* MCU position in the image (left of the MCU) */
UINT y /* MCU position in the image (top of the MCU) */
)
{
const INT CVACC = (sizeof (INT) > 2) ? 1024 : 128;
UINT ix, iy, mx, my, rx, ry;
INT yy, cb, cr;
BYTE *py, *pc, *rgb24;
JRECT rect;
mx = jd->msx * 8; my = jd->msy * 8; /* MCU size (pixel) */
rx = (x + mx <= jd->width) ? mx : jd->width - x; /* Output rectangular size (it may be clipped at right/bottom end) */
ry = (y + my <= jd->height) ? my : jd->height - y;
if (JD_USE_SCALE) {
rx >>= jd->scale; ry >>= jd->scale;
if (!rx || !ry) return JDR_OK; /* Skip this MCU if all pixel is to be rounded off */
x >>= jd->scale; y >>= jd->scale;
}
rect.left = x; rect.right = x + rx - 1; /* Rectangular area in the frame buffer */
rect.top = y; rect.bottom = y + ry - 1;
if (!JD_USE_SCALE || jd->scale != 3) { /* Not for 1/8 scaling */
/* Build an RGB MCU from discrete comopnents */
rgb24 = (BYTE*)jd->workbuf;
for (iy = 0; iy < my; iy++) {
pc = jd->mcubuf;
py = pc + iy * 8;
if (my == 16) { /* Double block height? */
pc += 64 * 4 + (iy >> 1) * 8;
if (iy >= 8) py += 64;
} else { /* Single block height */
pc += mx * 8 + iy * 8;
}
for (ix = 0; ix < mx; ix++) {
cb = pc[0] - 128; /* Get Cb/Cr component and restore right level */
cr = pc[64] - 128;
if (mx == 16) { /* Double block width? */
if (ix == 8) py += 64 - 8; /* Jump to next block if double block heigt */
pc += ix & 1; /* Increase chroma pointer every two pixels */
} else { /* Single block width */
pc++; /* Increase chroma pointer every pixel */
}
yy = *py++; /* Get Y component */
/* Convert YCbCr to RGB */
*rgb24++ = /* R */ BYTECLIP(yy + ((INT)(1.402 * CVACC) * cr) / CVACC);
*rgb24++ = /* G */ BYTECLIP(yy - ((INT)(0.344 * CVACC) * cb + (INT)(0.714 * CVACC) * cr) / CVACC);
*rgb24++ = /* B */ BYTECLIP(yy + ((INT)(1.772 * CVACC) * cb) / CVACC);
}
}
/* Descale the MCU rectangular if needed */
if (JD_USE_SCALE && jd->scale) {
UINT x, y, r, g, b, s, w, a;
BYTE *op;
/* Get averaged RGB value of each square correcponds to a pixel */
s = jd->scale * 2; /* Bumber of shifts for averaging */
w = 1 << jd->scale; /* Width of square */
a = (mx - w) * 3; /* Bytes to skip for next line in the square */
op = (BYTE*)jd->workbuf;
for (iy = 0; iy < my; iy += w) {
for (ix = 0; ix < mx; ix += w) {
rgb24 = (BYTE*)jd->workbuf + (iy * mx + ix) * 3;
r = g = b = 0;
for (y = 0; y < w; y++) { /* Accumulate RGB value in the square */
for (x = 0; x < w; x++) {
r += *rgb24++;
g += *rgb24++;
b += *rgb24++;
}
rgb24 += a;
} /* Put the averaged RGB value as a pixel */
*op++ = (BYTE)(r >> s);
*op++ = (BYTE)(g >> s);
*op++ = (BYTE)(b >> s);
}
}
}
} else { /* For only 1/8 scaling (left-top pixel in each block are the DC value of the block) */
/* Build a 1/8 descaled RGB MCU from discrete comopnents */
rgb24 = (BYTE*)jd->workbuf;
pc = jd->mcubuf + mx * my;
cb = pc[0] - 128; /* Get Cb/Cr component and restore right level */
cr = pc[64] - 128;
for (iy = 0; iy < my; iy += 8) {
py = jd->mcubuf;
if (iy == 8) py += 64 * 2;
for (ix = 0; ix < mx; ix += 8) {
yy = *py; /* Get Y component */
py += 64;
/* Convert YCbCr to RGB */
*rgb24++ = /* R */ BYTECLIP(yy + ((INT)(1.402 * CVACC) * cr / CVACC));
*rgb24++ = /* G */ BYTECLIP(yy - ((INT)(0.344 * CVACC) * cb + (INT)(0.714 * CVACC) * cr) / CVACC);
*rgb24++ = /* B */ BYTECLIP(yy + ((INT)(1.772 * CVACC) * cb / CVACC));
}
}
}
/* Squeeze up pixel table if a part of MCU is to be truncated */
mx >>= jd->scale;
if (rx < mx) {
BYTE *s, *d;
UINT x, y;
s = d = (BYTE*)jd->workbuf;
for (y = 0; y < ry; y++) {
for (x = 0; x < rx; x++) { /* Copy effective pixels */
*d++ = *s++;
*d++ = *s++;
*d++ = *s++;
}
s += (mx - rx) * 3; /* Skip truncated pixels */
}
}
/* Convert RGB888 to RGB565 if needed */
if (JD_FORMAT == 1) {
BYTE *s = (BYTE*)jd->workbuf;
WORD w, *d = (WORD*)s;
UINT n = rx * ry;
do {
w = (*s++ & 0xF8) << 8; /* RRRRR----------- */
w |= (*s++ & 0xFC) << 3; /* -----GGGGGG----- */
w |= *s++ >> 3; /* -----------BBBBB */
*d++ = w;
} while (--n);
}
/* Output the RGB rectangular */
return outfunc(jd, jd->workbuf, &rect) ? JDR_OK : JDR_INTR;
}
/*-----------------------------------------------------------------------*/
/* Process restart interval */
/*-----------------------------------------------------------------------*/
static
JRESULT restart (
JDEC* jd, /* Pointer to the decompressor object */
WORD rstn /* Expected restert sequense number */
)
{
UINT i, dc;
WORD d;
BYTE *dp;
/* Discard padding bits and get two bytes from the input stream */
dp = jd->dptr; dc = jd->dctr;
d = 0;
for (i = 0; i < 2; i++) {
if (!dc) { /* No input data is available, re-fill input buffer */
dp = jd->inbuf;
dc = jd->infunc(jd, dp, JD_SZBUF);
if (!dc) return JDR_INP;
} else {
dp++;
}
dc--;
d = (d << 8) | *dp; /* Get a byte */
}
jd->dptr = dp; jd->dctr = dc; jd->dmsk = 0;
/* Check the marker */
if ((d & 0xFFD8) != 0xFFD0 || (d & 7) != (rstn & 7))
return JDR_FMT1; /* Err: expected RSTn marker is not detected (may be collapted data) */
/* Reset DC offset */
jd->dcv[2] = jd->dcv[1] = jd->dcv[0] = 0;
return JDR_OK;
}
/*-----------------------------------------------------------------------*/
/* Analyze the JPEG image and Initialize decompressor object */
/*-----------------------------------------------------------------------*/
#define LDB_WORD(ptr) (WORD)(((WORD)*((BYTE*)(ptr))<<8)|(WORD)*(BYTE*)((ptr)+1))
JRESULT jd_prepare (
JDEC* jd, /* Blank decompressor object */
UINT (*infunc)(JDEC*, BYTE*, UINT), /* JPEG strem input function */
void* pool, /* Working buffer for the decompression session */
UINT sz_pool, /* Size of working buffer */
void* dev /* I/O device identifier for the session */
)
{
BYTE *seg, b;
WORD marker;
DWORD ofs;
UINT n, i, j, len;
JRESULT rc;
if (!pool) return JDR_PAR;
jd->pool = pool; /* Work memroy */
jd->sz_pool = sz_pool; /* Size of given work memory */
jd->infunc = infunc; /* Stream input function */
jd->device = dev; /* I/O device identifier */
jd->nrst = 0; /* No restart interval (default) */
for (i = 0; i < 2; i++) { /* Nulls pointers */
for (j = 0; j < 2; j++) {
jd->huffbits[i][j] = 0;
jd->huffcode[i][j] = 0;
jd->huffdata[i][j] = 0;
}
}
for (i = 0; i < 4; i++) jd->qttbl[i] = 0;
jd->inbuf = seg = alloc_pool(jd, JD_SZBUF); /* Allocate stream input buffer */
if (!seg) return JDR_MEM1;
if (jd->infunc(jd, seg, 2) != 2) return JDR_INP;/* Check SOI marker */
if (LDB_WORD(seg) != 0xFFD8) return JDR_FMT1; /* Err: SOI is not detected */
ofs = 2;
for (;;) {
/* Get a JPEG marker */
if (jd->infunc(jd, seg, 4) != 4) return JDR_INP;
marker = LDB_WORD(seg); /* Marker */
len = LDB_WORD(seg + 2); /* Length field */
if (len <= 2 || (marker >> 8) != 0xFF) return JDR_FMT1;
len -= 2; /* Content size excluding length field */
ofs += 4 + len; /* Number of bytes loaded */
switch (marker & 0xFF) {
case 0xC0: /* SOF0 (baseline JPEG) */
/* Load segment data */
if (len > JD_SZBUF) return JDR_MEM2;
if (jd->infunc(jd, seg, len) != len) return JDR_INP;
jd->width = LDB_WORD(seg+3); /* Image width in unit of pixel */
jd->height = LDB_WORD(seg+1); /* Image height in unit of pixel */
if (seg[5] != 3) return JDR_FMT3; /* Err: Supports only Y/Cb/Cr format */
/* Check three image components */
for (i = 0; i < 3; i++) {
b = seg[7 + 3 * i]; /* Get sampling factor */
if (!i) { /* Y component */
if (b != 0x11 && b != 0x22 && b != 0x21)/* Check sampling factor */
return JDR_FMT3; /* Err: Supports only 4:4:4, 4:2:0 or 4:2:2 */
jd->msx = b >> 4; jd->msy = b & 15; /* Size of MCU [blocks] */
} else { /* Cb/Cr component */
if (b != 0x11) return JDR_FMT3; /* Err: Sampling factor of Cr/Cb must be 1 */
}
b = seg[8 + 3 * i]; /* Get dequantizer table ID for this component */
if (b > 3) return JDR_FMT3; /* Err: Invalid ID */
jd->qtid[i] = b;
}
break;
case 0xDD: /* DRI */
/* Load segment data */
if (len > JD_SZBUF) return JDR_MEM2;
if (jd->infunc(jd, seg, len) != len) return JDR_INP;
/* Get restart interval (MCUs) */
jd->nrst = LDB_WORD(seg);
break;
case 0xC4: /* DHT */
/* Load segment data */
if (len > JD_SZBUF) return JDR_MEM2;
if (jd->infunc(jd, seg, len) != len) return JDR_INP;
/* Create huffman tables */
rc = create_huffman_tbl(jd, seg, len);
if (rc) return rc;
break;
case 0xDB: /* DQT */
/* Load segment data */
if (len > JD_SZBUF) return JDR_MEM2;
if (jd->infunc(jd, seg, len) != len) return JDR_INP;
/* Create de-quantizer tables */
rc = create_qt_tbl(jd, seg, len);
if (rc) return rc;
break;
case 0xDA: /* SOS */
/* Load segment data */
if (len > JD_SZBUF) return JDR_MEM2;
if (jd->infunc(jd, seg, len) != len) return JDR_INP;
if (!jd->width || !jd->height) return JDR_FMT1; /* Err: Invalid image size */
if (seg[0] != 3) return JDR_FMT3; /* Err: Supports only three color components format */
/* Check if all tables corresponding to each components have been loaded */
for (i = 0; i < 3; i++) {
b = seg[2 + 2 * i]; /* Get huffman table ID */
if (b != 0x00 && b != 0x11) return JDR_FMT3; /* Err: Different table number for DC/AC element */
b = i ? 1 : 0;
if (!jd->huffbits[b][0] || !jd->huffbits[b][1]) /* Check huffman table for this component */
return JDR_FMT1; /* Err: Huffman table not loaded */
if (!jd->qttbl[jd->qtid[i]]) return JDR_FMT1; /* Err: Dequantizer table not loaded */
}
/* Allocate working buffer for MCU and RGB */
n = jd->msy * jd->msx; /* Number of Y blocks in the MCU */
if (!n) return JDR_FMT1; /* Err: SOF0 has not been loaded */
len = n * 64 * 2 + 64; /* Allocate buffer for IDCT and RGB output */
if (len < 256) len = 256; /* but at least 256 byte is required for IDCT */
jd->workbuf = alloc_pool(jd, len); /* and it may occupy a part of following MCU working buffer for RGB output */
if (!jd->workbuf) return JDR_MEM1; /* Err: not enough memory */
jd->mcubuf = alloc_pool(jd, (n + 2) * 64); /* Allocate MCU working buffer */
if (!jd->mcubuf) return JDR_MEM1; /* Err: not enough memory */
/* Pre-load the JPEG data to extract it from the bit stream */
jd->dptr = seg; jd->dctr = 0; jd->dmsk = 0; /* Prepare to read bit stream */
if (ofs %= JD_SZBUF) { /* Align read offset to JD_SZBUF */
jd->dctr = jd->infunc(jd, seg + ofs, JD_SZBUF - (UINT)ofs);
jd->dptr = seg + ofs - 1;
}
return JDR_OK; /* Initialization succeeded. Ready to decompress the JPEG image. */
case 0xC1: /* SOF1 */
case 0xC2: /* SOF2 */
case 0xC3: /* SOF3 */
case 0xC5: /* SOF5 */
case 0xC6: /* SOF6 */
case 0xC7: /* SOF7 */
case 0xC9: /* SOF9 */
case 0xCA: /* SOF10 */
case 0xCB: /* SOF11 */
case 0xCD: /* SOF13 */
case 0xCE: /* SOF14 */
case 0xCF: /* SOF15 */
case 0xD9: /* EOI */
return JDR_FMT3; /* Unsuppoted JPEG standard (may be progressive JPEG) */
case 0xE0: /* APP0 */
case 0xE1: /* APP1 */
case 0xE2: /* APP2 */
case 0xE3: /* APP3 */
case 0xE4: /* APP4 */
case 0xE5: /* APP5 */
case 0xE6: /* APP6 */
case 0xE7: /* APP7 */
case 0xE8: /* APP8 */
case 0xE9: /* APP9 */
case 0xEA: /* APP10 */
case 0xEB: /* APP11 */
case 0xEC: /* APP12 */
case 0xED: /* APP13 */
case 0xEE: /* APP14 */
case 0xEF: /* APP15 */
case 0xFE: /* COM */
/* Load segment data */
if (len > JD_SZBUF) return JDR_MEM2;
if (jd->infunc(jd, seg, len) != len) return JDR_INP;
break;
default: /* Unknown segment (comment, exif or etc..) */
/* Skip segment data */
if (jd->infunc(jd, 0, len) != len) /* Null pointer specifies to skip bytes of stream */
return JDR_INP;
}
}
}
/*-----------------------------------------------------------------------*/
/* Start to decompress the JPEG picture */
/*-----------------------------------------------------------------------*/
JRESULT jd_decomp (
JDEC* jd, /* Initialized decompression object */
UINT (*outfunc)(JDEC*, void*, JRECT*), /* RGB output function */
BYTE scale /* Output de-scaling factor (0 to 3) */
)
{
UINT x, y, mx, my;
WORD rst, rsc;
JRESULT rc;
if (scale > (JD_USE_SCALE ? 3 : 0)) return JDR_PAR;
jd->scale = scale;
mx = jd->msx * 8; my = jd->msy * 8; /* Size of the MCU (pixel) */
jd->dcv[2] = jd->dcv[1] = jd->dcv[0] = 0; /* Initialize DC values */
rst = rsc = 0;
rc = JDR_OK;
for (y = 0; y < jd->height; y += my) { /* Vertical loop of MCUs */
for (x = 0; x < jd->width; x += mx) { /* Horizontal loop of MCUs */
if (jd->nrst && rst++ == jd->nrst) { /* Process restart interval if enabled */
rc = restart(jd, rsc++);
if (rc != JDR_OK) return rc;
rst = 1;
}
rc = mcu_load(jd); /* Load an MCU (decompress huffman coded stream and IDCT) */
if (rc != JDR_OK) return rc;
rc = mcu_output(jd, outfunc, x, y); /* Output the MCU (color space conversion, scaling and output) */
if (rc != JDR_OK) return rc;
}
}
return rc;
}