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| author | Kostya Shishkov <kostya.shishkov@gmail.com> | 2006-07-16 03:47:34 +0000 |
|---|---|---|
| committer | Kostya Shishkov <kostya.shishkov@gmail.com> | 2006-07-16 03:47:34 +0000 |
| commit | 0a45801f8ef0f951250f9ccc19fdd9f7bfdba5e8 (patch) | |
| tree | 3761d1584dce9cf5a71f3cbe818f127a6ca62242 /libavcodec | |
| parent | c5b32ec1cbc78e4327462c07535bda4ec601def0 (diff) | |
Correct inverse quantization for P-frames
Originally committed as revision 5760 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/vc1.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/libavcodec/vc1.c b/libavcodec/vc1.c index bdd6b87713..85eb54f723 100644 --- a/libavcodec/vc1.c +++ b/libavcodec/vc1.c @@ -1331,10 +1331,11 @@ static int vc1_parse_frame_header(VC1Context *v, GetBitContext* gb) else v->pq = pquant_table[v->quantizer_mode-1][pqindex]; + v->pquantizer = 1; if (v->quantizer_mode == QUANT_FRAME_IMPLICIT) v->pquantizer = pqindex < 9; - if (v->quantizer_mode == QUANT_UNIFORM || v->quantizer_mode == QUANT_NON_UNIFORM) - v->pquantizer = v->quantizer_mode == QUANT_UNIFORM; + if (v->quantizer_mode == QUANT_NON_UNIFORM) + v->pquantizer = 0; v->pqindex = pqindex; if (pqindex < 9) v->halfpq = get_bits(gb, 1); else v->halfpq = 0; @@ -2151,7 +2152,7 @@ static int vc1_decode_intra_block(VC1Context *v, DCTELEM block[64], int n, int c ac_val = s->ac_val[0][0] + s->block_index[n] * 16; ac_val2 = ac_val; - scale = mquant * 2; + scale = mquant * 2 + v->halfpq; if(dc_pred_dir) //left ac_val -= 16; @@ -2289,7 +2290,7 @@ static int vc1_decode_p_block(VC1Context *v, DCTELEM block[64], int n, int mquan if(ttblk == TT_8X4_TOP || ttblk == TT_8X4_BOTTOM) ttblk = TT_8X4; if(ttblk == TT_4X8_RIGHT || ttblk == TT_4X8_LEFT) ttblk = TT_4X8; } - scale = 2 * mquant; + scale = 2 * mquant + v->halfpq; // convert transforms like 8X4_TOP to generic TT and SUBBLKPAT if(ttblk == TT_8X4_TOP || ttblk == TT_8X4_BOTTOM) { @@ -2311,6 +2312,8 @@ static int vc1_decode_p_block(VC1Context *v, DCTELEM block[64], int n, int mquan break; idx = vc1_simple_progressive_8x8_zz[i++]; block[idx] = value * scale; + if(!v->pquantizer) + block[idx] += (block[idx] < 0) ? -mquant : mquant; } vc1_inv_trans(block, 8, 8); break; @@ -2326,6 +2329,8 @@ static int vc1_decode_p_block(VC1Context *v, DCTELEM block[64], int n, int mquan break; idx = vc1_simple_progressive_4x4_zz[i++]; block[idx + off] = value * scale; + if(!v->pquantizer) + block[idx + off] += (block[idx + off] < 0) ? -mquant : mquant; } if(!(subblkpat & (1 << (3 - j)))) vc1_inv_trans(block + off, 4, 4); @@ -2343,6 +2348,8 @@ static int vc1_decode_p_block(VC1Context *v, DCTELEM block[64], int n, int mquan break; idx = vc1_simple_progressive_8x4_zz[i++]; block[idx + off] = value * scale; + if(!v->pquantizer) + block[idx + off] += (block[idx + off] < 0) ? -mquant : mquant; } if(!(subblkpat & (1 << (1 - j)))) vc1_inv_trans(block + off, 8, 4); @@ -2360,6 +2367,8 @@ static int vc1_decode_p_block(VC1Context *v, DCTELEM block[64], int n, int mquan break; idx = vc1_simple_progressive_4x8_zz[i++]; block[idx + off] = value * scale; + if(!v->pquantizer) + block[idx + off] += (block[idx + off] < 0) ? -mquant : mquant; } if(!(subblkpat & (1 << (1 - j)))) vc1_inv_trans(block + off, 4, 8); |