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| author | Michael Niedermayer <michaelni@gmx.at> | 2006-08-24 11:18:41 +0000 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2006-08-24 11:18:41 +0000 |
| commit | e90a72701ee7d6613d2681c87064bd69c3a2e448 (patch) | |
| tree | a62babfe72933461be3ad5265261400125564125 | |
| parent | 5340a0bc9c96114bd6b2bb2b79a3e8453435ce0a (diff) | |
| download | ffmpeg-e90a72701ee7d6613d2681c87064bd69c3a2e448.tar.gz | |
avoid a few if(x==0) checks in the inner loops
Originally committed as revision 6073 to svn://svn.ffmpeg.org/ffmpeg/trunk
| -rw-r--r-- | libavcodec/mpegaudiodec.c | 40 |
1 files changed, 30 insertions, 10 deletions
diff --git a/libavcodec/mpegaudiodec.c b/libavcodec/mpegaudiodec.c index 3b11cfe7b0..61baedc9db 100644 --- a/libavcodec/mpegaudiodec.c +++ b/libavcodec/mpegaudiodec.c @@ -2299,12 +2299,22 @@ static int mp_decode_layer3(MPADecodeContext *s) if (g->block_type == 2) { n = g->switch_point ? 17 : 18; j = 0; - for(i=0;i<n;i++) - g->scale_factors[j++] = get_bitsz(&s->gb, slen1); - for(i=0;i<18;i++) - g->scale_factors[j++] = get_bitsz(&s->gb, slen2); - for(i=0;i<3;i++) - g->scale_factors[j++] = 0; + if(slen1){ + for(i=0;i<n;i++) + g->scale_factors[j++] = get_bits(&s->gb, slen1); + }else{ + for(i=0;i<n;i++) + g->scale_factors[j++] = 0; + } + if(slen2){ + for(i=0;i<18;i++) + g->scale_factors[j++] = get_bits(&s->gb, slen2); + for(i=0;i<3;i++) + g->scale_factors[j++] = 0; + }else{ + for(i=0;i<21;i++) + g->scale_factors[j++] = 0; + } } else { sc = granules[ch][0].scale_factors; j = 0; @@ -2312,8 +2322,13 @@ static int mp_decode_layer3(MPADecodeContext *s) n = (k == 0 ? 6 : 5); if ((g->scfsi & (0x8 >> k)) == 0) { slen = (k < 2) ? slen1 : slen2; - for(i=0;i<n;i++) - g->scale_factors[j++] = get_bitsz(&s->gb, slen); + if(slen){ + for(i=0;i<n;i++) + g->scale_factors[j++] = get_bits(&s->gb, slen); + }else{ + for(i=0;i<n;i++) + g->scale_factors[j++] = 0; + } } else { /* simply copy from last granule */ for(i=0;i<n;i++) { @@ -2375,8 +2390,13 @@ static int mp_decode_layer3(MPADecodeContext *s) for(k=0;k<4;k++) { n = lsf_nsf_table[tindex2][tindex][k]; sl = slen[k]; - for(i=0;i<n;i++) - g->scale_factors[j++] = get_bitsz(&s->gb, sl); + if(s1){ + for(i=0;i<n;i++) + g->scale_factors[j++] = get_bits(&s->gb, sl); + }else{ + for(i=0;i<n;i++) + g->scale_factors[j++] = 0; + } } /* XXX: should compute exact size */ for(;j<40;j++) |