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| author | Michael Niedermayer <michaelni@gmx.at> | 2003-09-24 19:45:57 +0000 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2003-09-24 19:45:57 +0000 |
| commit | 34f60ee61bff1f693ad89ff1daa9934e5f6f90fa (patch) | |
| tree | cdf90e32b99e1520f74a42ff7232fceff4018335 /libavcodec | |
| parent | 98b0858e1089a65f25041868adf6c00e43861846 (diff) | |
| download | ffmpeg-streaming-34f60ee61bff1f693ad89ff1daa9934e5f6f90fa.zip ffmpeg-streaming-34f60ee61bff1f693ad89ff1daa9934e5f6f90fa.tar.gz | |
slight quality improvement ( < +0.04 PSNR) for high bitrate videos with trellis quantization
Originally committed as revision 2300 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/mpegvideo.c | 42 |
1 files changed, 41 insertions, 1 deletions
diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c index b14aa54..fa915e3 100644 --- a/libavcodec/mpegvideo.c +++ b/libavcodec/mpegvideo.c @@ -3997,7 +3997,7 @@ static int dct_quantize_trellis_c(MpegEncContext *s, int last_i= 0; int coeff[3][64]; int coeff_count[64]; - int lambda, qmul, qadd, start_i, last_non_zero, i; + int lambda, qmul, qadd, start_i, last_non_zero, i, dc; const int esc_length= s->ac_esc_length; uint8_t * length; uint8_t * last_length; @@ -4206,12 +4206,52 @@ static int dct_quantize_trellis_c(MpegEncContext *s, } } + dc= block[0]; last_non_zero= last_i - 1 + start_i; memset(block + start_i, 0, (64-start_i)*sizeof(DCTELEM)); if(last_non_zero < start_i) return last_non_zero; + if(last_non_zero == 0 && start_i == 0){ + int best_level= 0; + int best_score= dc * dc; + + for(i=0; i<coeff_count[0]; i++){ + const int level= coeff[i][0]; + int unquant_coeff, score, distoration; + + if(s->out_format == FMT_H263){ + if(level>0){ + unquant_coeff= (level*qmul + qadd)>>3; + }else{ + unquant_coeff= (level*qmul - qadd)>>3; + } + }else{ //MPEG1 + if (level < 0) { + unquant_coeff = ((((-level) << 1) + 1) * qscale * ((int) s->inter_matrix[0])) >> 4; + unquant_coeff = -((unquant_coeff - 1) | 1); + } else { + unquant_coeff = ((( level << 1) + 1) * qscale * ((int) s->inter_matrix[0])) >> 4; + unquant_coeff = (unquant_coeff - 1) | 1; + } + } + unquant_coeff = (unquant_coeff + 4) >> 3; + unquant_coeff<<= 3 + 3; + + distoration= (unquant_coeff - dc) * (unquant_coeff - dc); + score= distoration + last_length[UNI_AC_ENC_INDEX(0, level+64)]*lambda; + if(score < best_score){ + best_score= score; + best_level= level; + } + } + block[0]= best_level; + if(best_level == 0) + last_non_zero=-1; + return last_non_zero; + } + i= last_i; assert(last_level); //FIXME use permutated scantable |
