/*----------------------------------------------------------------------------/ / 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 = (BYTE)((*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) */ jd->format = 0; /* use RGB888 (3 BYTE/pix) 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; }