diff options
Diffstat (limited to 'converter/ppm/ppmtompeg/postdct.c')
| -rw-r--r-- | converter/ppm/ppmtompeg/postdct.c | 508 |
1 files changed, 257 insertions, 251 deletions
diff --git a/converter/ppm/ppmtompeg/postdct.c b/converter/ppm/ppmtompeg/postdct.c index 56a23de9..f3de075a 100644 --- a/converter/ppm/ppmtompeg/postdct.c +++ b/converter/ppm/ppmtompeg/postdct.c @@ -1,15 +1,15 @@ /*===========================================================================* - * postdct.c * - * * - * Procedures concerned with MPEG post-DCT processing: * - * quantization and RLE Huffman encoding * - * * - * EXPORTED PROCEDURES: * - * Mpost_QuantZigBlock * - * Mpost_RLEHuffIBlock * - * Mpost_RLEHuffPBlock * - * Mpost_UnQuantZigBlock * - * * + * postdct.c * + * * + * Procedures concerned with MPEG post-DCT processing: * + * quantization and RLE Huffman encoding * + * * + * EXPORTED PROCEDURES: * + * Mpost_QuantZigBlock * + * Mpost_RLEHuffIBlock * + * Mpost_RLEHuffPBlock * + * Mpost_UnQuantZigBlock * + * * *===========================================================================*/ /* @@ -164,8 +164,8 @@ int32 niqtable[] = { 16, 16, 16, 16, 16, 16, 16, 16 }; -int32 *customQtable = NULL; -int32 *customNIQtable = NULL; +int32 *customQtable = NULL; +int32 *customNIQtable = NULL; /*==================* * GLOBAL VARIABLES * @@ -181,10 +181,10 @@ extern boolean realQuiet; * * Mpost_UnQuantZigBlock * - * unquantize and zig-zag (decode) a single block - * see section 2.4.4.1 of MPEG standard + * unquantize and zig-zag (decode) a single block + * see section 2.4.4.1 of MPEG standard * - * RETURNS: nothing + * RETURNS: nothing * * SIDE EFFECTS: none * @@ -197,77 +197,78 @@ Mpost_UnQuantZigBlock(in, out, qscale, iblock) boolean iblock; { register int index; - int start; - int position; - register int qentry; - int level, coeff; - + int start; + int position; + register int qentry; + int level, coeff; + if ( iblock ) { - /* qtable[0] must be 8 */ - out[0][0] = (int16)(in[0] * 8); + /* qtable[0] must be 8 */ + out[0][0] = (int16)(in[0] * 8); - /* don't need to do anything fancy here, because we saved orig - value, not encoded dc value */ - start = 1; + /* don't need to do anything fancy here, because we saved orig + value, not encoded dc value */ + start = 1; } else { - start = 0; + start = 0; } for ( index = start; index < DCTSIZE_SQ; index++ ) { - position = ZAG[index]; - level = in[index]; - - if (level == 0) { - ((int16 *)out)[position] = 0; - continue; - } - - - if ( iblock ) { - qentry = qtable[position] * qscale; - coeff = (level*qentry)/8; - if ( (coeff & 1) == 0 ) { - if ( coeff < 0 ) { - coeff++; - } else if ( coeff > 0 ) { - coeff--; - } - } - } else { - qentry = niqtable[position] * qscale; - if ( level == 0 ) { - coeff = 0; - } else if ( level < 0 ) { - coeff = (((2*level)-1)*qentry) / 16; - if ( (coeff & 1) == 0 ) { - coeff++; - } - } else { - coeff = (((2*level)+1)*qentry) >> 4; - if ( (coeff & 1) == 0 ) { - coeff--; - } - } - - if ( coeff > 2047 ) { - coeff = 2047; - } else if ( coeff < -2048 ) { - coeff = -2048; - } + position = ZAG[index]; + level = in[index]; + + if (level == 0) { + ((int16 *)out)[position] = 0; + continue; } - ((int16 *)out)[position] = coeff; + + if ( iblock ) { + qentry = qtable[position] * qscale; + coeff = (level*qentry)/8; + if ( (coeff & 1) == 0 ) { + if ( coeff < 0 ) { + coeff++; + } else if ( coeff > 0 ) { + coeff--; + } + } + } else { + qentry = niqtable[position] * qscale; + if ( level == 0 ) { + coeff = 0; + } else if ( level < 0 ) { + coeff = (((2*level)-1)*qentry) / 16; + if ( (coeff & 1) == 0 ) { + coeff++; + } + } else { + coeff = (((2*level)+1)*qentry) >> 4; + if ( (coeff & 1) == 0 ) { + coeff--; + } + } + + if ( coeff > 2047 ) { + coeff = 2047; + } else if ( coeff < -2048 ) { + coeff = -2048; + } + } + + ((int16 *)out)[position] = coeff; } } + /*===========================================================================* * * Mpost_QuantZigBlock * - * quantize and zigzags a block + * quantize and zigzags a block * - * RETURNS: MPOST_OVERFLOW if a generated value is outside |255| + * RETURNS: MPOST_OVERFLOW if a generated value is outside |255| * MPOST_ZERO if all coeffs are zero * MPOST_NON_ZERO otherwisw * @@ -287,7 +288,7 @@ Mpost_QuantZigBlock(in, out, qscale, iblock) register int position; boolean nonZero = FALSE; boolean overflow = FALSE; - + DBG_PRINT(("Mpost_QuantZigBlock...\n")); if (iblock) { /* @@ -296,7 +297,7 @@ Mpost_QuantZigBlock(in, out, qscale, iblock) */ temp = ((int16 *) in)[ZAG[0]]; qentry = qtable[ZAG[0]]; - + if (temp < 0) { temp = -temp; temp += (qentry >> 1); @@ -310,60 +311,60 @@ Mpost_QuantZigBlock(in, out, qscale, iblock) nonZero = TRUE; } out[0] = temp; - + for (i = 1; i < DCTSIZE_SQ; i++) { position = ZAG[i]; temp = ((int16 *) in)[position]; qentry = qtable[position] * qscale; - + /* see 1993 MPEG doc, section D.6.3.4 */ if (temp < 0) { - temp = -temp; - temp = (temp << 3); /* temp > 0 */ - temp += (qentry >> 1); - temp /= qentry; - temp = -temp; + temp = -temp; + temp = (temp << 3); /* temp > 0 */ + temp += (qentry >> 1); + temp /= qentry; + temp = -temp; } else { - temp = (temp << 3); /* temp > 0 */ - temp += (qentry >> 1); - temp /= qentry; + temp = (temp << 3); /* temp > 0 */ + temp += (qentry >> 1); + temp /= qentry; } - + if ( temp != 0 ) { - nonZero = TRUE; - out[i] = temp; - if (temp < -255) { - temp = -255; - overflow = TRUE; - } else if (temp > 255) { - temp = 255; - overflow = TRUE; - } + nonZero = TRUE; + out[i] = temp; + if (temp < -255) { + temp = -255; + overflow = TRUE; + } else if (temp > 255) { + temp = 255; + overflow = TRUE; + } } else out[i]=0; } } else { for (i = 0; i < DCTSIZE_SQ; i++) { position = ZAG[i]; temp = ((int16 *) in)[position]; - + /* multiply by non-intra qtable */ qentry = qscale * niqtable[position]; - + /* see 1993 MPEG doc, D.6.4.5 */ temp *= 8; - temp /= qentry; /* truncation toward 0 -- correct */ - + temp /= qentry; /* truncation toward 0 -- correct */ + if ( temp != 0 ) { - nonZero = TRUE; - out[i] = temp; - if (temp < -255) { - temp = -255; - overflow = TRUE; - } else if (temp > 255) { - temp = 255; - overflow = TRUE; - } - + nonZero = TRUE; + out[i] = temp; + if (temp < -255) { + temp = -255; + overflow = TRUE; + } else if (temp > 255) { + temp = 255; + overflow = TRUE; + } + } else out[i]=0; } } @@ -379,9 +380,9 @@ Mpost_QuantZigBlock(in, out, qscale, iblock) * * Mpost_RLEHuffIBlock * - * generate the huffman bits from an I-block + * generate the huffman bits from an I-block * - * RETURNS: nothing + * RETURNS: nothing * * SIDE EFFECTS: none * @@ -403,70 +404,71 @@ Mpost_RLEHuffIBlock(in, out) * specially, elsewhere. Not here. */ for (i = 1; i < DCTSIZE_SQ; i++) { - cur = in[i]; - acur = ABS(cur); - if (cur) { - if ( (nzeros < HUFF_MAXRUN) && (acur < huff_maxlevel[nzeros])) { - /* - * encode using the Huffman tables - */ - - DBG_PRINT(("rle_huff %02d.%02d: Run %02d, Level %4d\n", i, ZAG[i], nzeros, cur)); - code = (huff_table[nzeros])[acur]; - nbits = (huff_bits[nzeros])[acur]; - - if (cur < 0) { - code |= 1; /* the sign bit */ - } - Bitio_Write(out, code, nbits); - } else { - /* - * encode using the escape code - */ - DBG_PRINT(("Escape\n")); - Bitio_Write(out, 0x1, 6); /* ESCAPE */ - DBG_PRINT(("Run Length\n")); - Bitio_Write(out, nzeros, 6); /* Run-Length */ - - /* - * this shouldn't happen, but the other - * choice is to bomb out and dump core... - * Hmmm, seems to happen with small Qtable entries (1) -srs - */ - if (cur < -255) { - cur = -255; - } else if (cur > 255) { - cur = 255; - } - - DBG_PRINT(("Level\n")); - if (acur < 128) { - Bitio_Write(out, cur, 8); - } else { - if (cur < 0) { - Bitio_Write(out, 0x8001 + cur + 255, 16); - } else { - Bitio_Write(out, cur, 16); - } - } - } - nzeros = 0; - } else { - nzeros++; - } + cur = in[i]; + acur = ABS(cur); + if (cur) { + if ( (nzeros < HUFF_MAXRUN) && (acur < huff_maxlevel[nzeros])) { + /* + * encode using the Huffman tables + */ + + DBG_PRINT(("rle_huff %02d.%02d: Run %02d, Level %4d\n", i, ZAG[i], nzeros, cur)); + code = (huff_table[nzeros])[acur]; + nbits = (huff_bits[nzeros])[acur]; + + if (cur < 0) { + code |= 1; /* the sign bit */ + } + Bitio_Write(out, code, nbits); + } else { + /* + * encode using the escape code + */ + DBG_PRINT(("Escape\n")); + Bitio_Write(out, 0x1, 6); /* ESCAPE */ + DBG_PRINT(("Run Length\n")); + Bitio_Write(out, nzeros, 6); /* Run-Length */ + + /* + * this shouldn't happen, but the other + * choice is to bomb out and dump core... + * Hmmm, seems to happen with small Qtable entries (1) -srs + */ + if (cur < -255) { + cur = -255; + } else if (cur > 255) { + cur = 255; + } + + DBG_PRINT(("Level\n")); + if (acur < 128) { + Bitio_Write(out, cur, 8); + } else { + if (cur < 0) { + Bitio_Write(out, 0x8001 + cur + 255, 16); + } else { + Bitio_Write(out, cur, 16); + } + } + } + nzeros = 0; + } else { + nzeros++; + } } DBG_PRINT(("End of block\n")); - Bitio_Write(out, 0x2, 2); /* end of block marker */ + Bitio_Write(out, 0x2, 2); /* end of block marker */ } + /*===========================================================================* * * Mpost_RLEHuffPBlock * - * generate the huffman bits from an P-block + * generate the huffman bits from an P-block * - * RETURNS: nothing + * RETURNS: nothing * * SIDE EFFECTS: none * @@ -488,90 +490,91 @@ Mpost_RLEHuffPBlock(in, out) * yes, Virginia, we start at 0. */ for (i = 0; i < DCTSIZE_SQ; i++) { - cur = in[i]; - acur = ABS(cur); - if (cur) { - if ((nzeros < HUFF_MAXRUN) && (acur < huff_maxlevel[nzeros])) { - /* - * encode using the Huffman tables - */ - - DBG_PRINT(("rle_huff %02d.%02d: Run %02d, Level %4d\n", i, ZAG[i], nzeros, cur)); - if ( first_dct && (nzeros == 0) && (acur == 1) ) { - /* actually, only needs = 0x2 */ - code = (cur == 1) ? 0x2 : 0x3; - nbits = 2; - } else { - code = (huff_table[nzeros])[acur]; - nbits = (huff_bits[nzeros])[acur]; - } - - assert(nbits); - - if (cur < 0) { - code |= 1; /* the sign bit */ - } - Bitio_Write(out, code, nbits); - first_dct = FALSE; - } else { - /* - * encode using the escape code - */ - DBG_PRINT(("Escape\n")); - Bitio_Write(out, 0x1, 6); /* ESCAPE */ - DBG_PRINT(("Run Length\n")); - Bitio_Write(out, nzeros, 6); /* Run-Length */ - - /* - * this shouldn't happen, but the other - * choice is to bomb out and dump core... - * Hmmm, seems to happen with small Qtable entries (1) -srs - */ - if (cur < -255) { - cur = -255; - } else if (cur > 255) { - cur = 255; - } - - DBG_PRINT(("Level\n")); - if (acur < 128) { - Bitio_Write(out, cur, 8); - } else { - if (cur < 0) { - Bitio_Write(out, 0x8001 + cur + 255, 16); - } else { - Bitio_Write(out, cur, 16); - } - } - - first_dct = FALSE; - } - nzeros = 0; - } else { - nzeros++; - } + cur = in[i]; + acur = ABS(cur); + if (cur) { + if ((nzeros < HUFF_MAXRUN) && (acur < huff_maxlevel[nzeros])) { + /* + * encode using the Huffman tables + */ + + DBG_PRINT(("rle_huff %02d.%02d: Run %02d, Level %4d\n", i, ZAG[i], nzeros, cur)); + if ( first_dct && (nzeros == 0) && (acur == 1) ) { + /* actually, only needs = 0x2 */ + code = (cur == 1) ? 0x2 : 0x3; + nbits = 2; + } else { + code = (huff_table[nzeros])[acur]; + nbits = (huff_bits[nzeros])[acur]; + } + + assert(nbits); + + if (cur < 0) { + code |= 1; /* the sign bit */ + } + Bitio_Write(out, code, nbits); + first_dct = FALSE; + } else { + /* + * encode using the escape code + */ + DBG_PRINT(("Escape\n")); + Bitio_Write(out, 0x1, 6); /* ESCAPE */ + DBG_PRINT(("Run Length\n")); + Bitio_Write(out, nzeros, 6); /* Run-Length */ + + /* + * this shouldn't happen, but the other + * choice is to bomb out and dump core... + * Hmmm, seems to happen with small Qtable entries (1) -srs + */ + if (cur < -255) { + cur = -255; + } else if (cur > 255) { + cur = 255; + } + + DBG_PRINT(("Level\n")); + if (acur < 128) { + Bitio_Write(out, cur, 8); + } else { + if (cur < 0) { + Bitio_Write(out, 0x8001 + cur + 255, 16); + } else { + Bitio_Write(out, cur, 16); + } + } + + first_dct = FALSE; + } + nzeros = 0; + } else { + nzeros++; + } } /* actually, should REALLY return FALSE and not use this! */ - if ( first_dct ) { /* have to give a first_dct even if all 0's */ - fprintf(stderr, "HUFF called with all-zero coefficients\n"); - fprintf(stderr, "exiting...\n"); - exit(1); + if ( first_dct ) { /* have to give a first_dct even if all 0's */ + fprintf(stderr, "HUFF called with all-zero coefficients\n"); + fprintf(stderr, "exiting...\n"); + exit(1); } DBG_PRINT(("End of block\n")); - Bitio_Write(out, 0x2, 2); /* end of block marker */ + Bitio_Write(out, 0x2, 2); /* end of block marker */ } + /*===========================================================================* * * CalcRLEHuffLength * - * count the huffman bits for an P-block + * count the huffman bits for an P-block * - * RETURNS: number of bits + * RETURNS: number of bits * * SIDE EFFECTS: none * @@ -587,40 +590,43 @@ CalcRLEHuffLength(in) register int nbits; register int countbits=0; boolean first_dct = TRUE; - + for (i = 0; i < DCTSIZE_SQ; i++) { cur = in[i]; acur = ABS(cur); if (cur) { if ((nzeros < HUFF_MAXRUN) && (acur < huff_maxlevel[nzeros])) { - /* - * encode using the Huffman tables - */ - - if ( first_dct && (nzeros == 0) && (acur == 1) ) { - nbits = 2; - } else { - nbits = (huff_bits[nzeros])[acur]; - } - countbits += nbits; - first_dct = FALSE; + /* + * encode using the Huffman tables + */ + + if ( first_dct && (nzeros == 0) && (acur == 1) ) { + nbits = 2; + } else { + nbits = (huff_bits[nzeros])[acur]; + } + countbits += nbits; + first_dct = FALSE; } else { - countbits += 12; /* ESCAPE + runlength */ + countbits += 12; /* ESCAPE + runlength */ - if (acur < 128) { - countbits += 8; - } else { - countbits += 16; - } + if (acur < 128) { + countbits += 8; + } else { + countbits += 16; + } - first_dct = FALSE; + first_dct = FALSE; } nzeros = 0; } else { nzeros++; } } - + countbits += 2; /* end of block marker */ return countbits; } + + + |