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author | Michael Niedermayer <michaelni@gmx.at> | 2005-05-30 15:03:06 +0000 |
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committer | Michael Niedermayer <michaelni@gmx.at> | 2005-05-30 15:03:06 +0000 |
commit | de312e51d0797f679ede9d1aa6cfd0fa063e0337 (patch) | |
tree | 2e1d78582dd015f93c8546791afd22dc4b53168f /libavcodec/vorbis.c | |
parent | f56f96d80f59a06e8214aa98e5024d3e10ccef4f (diff) | |
download | ffmpeg-streaming-de312e51d0797f679ede9d1aa6cfd0fa063e0337.zip ffmpeg-streaming-de312e51d0797f679ede9d1aa6cfd0fa063e0337.tar.gz |
optimizations
Originally committed as revision 4320 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/vorbis.c')
-rw-r--r-- | libavcodec/vorbis.c | 34 |
1 files changed, 22 insertions, 12 deletions
diff --git a/libavcodec/vorbis.c b/libavcodec/vorbis.c index d1a09d5..d0f3c9c 100644 --- a/libavcodec/vorbis.c +++ b/libavcodec/vorbis.c @@ -1188,7 +1188,7 @@ static int vorbis_residue_decode(vorbis_context *vc, vorbis_residue *vr, uint_fa } // Decode the audio packet using the functions above -#define BIAS 384 +#define BIAS 385 static int vorbis_parse_audio_packet(vorbis_context *vc) { GetBitContext *gb=&vc->gb; @@ -1342,27 +1342,34 @@ static int vorbis_parse_audio_packet(vorbis_context *vc) { } retlen=vc->blocksize_1/2; } else { + buf += (vc->blocksize_1-vc->blocksize_0)/4; for(k=j, i=0;i<vc->blocksize_0/2;++i, k+=step) { - ret[k]=saved[i]+buf[(vc->blocksize_1-vc->blocksize_0)/4+i]*swin[i]+BIAS; + ret[k]=saved[i]+buf[i]*swin[i]+BIAS; } + buf += vc->blocksize_0/2; for(i=0;i<(vc->blocksize_1-vc->blocksize_0)/4;++i, k+=step) { - ret[k]=buf[vc->blocksize_0/2+(vc->blocksize_1-vc->blocksize_0)/4+i]+BIAS; + ret[k]=buf[i]+BIAS; } + buf=vc->buf; retlen=vc->blocksize_0/2+(vc->blocksize_1-vc->blocksize_0)/4; } // -- save if (next_window) { + buf += vc->blocksize_1/2; + lwin += vc->blocksize_1/2-1; for(i=0;i<vc->blocksize_1/2;++i) { - saved[i]=buf[vc->blocksize_1/2+i]*lwin[vc->blocksize_1/2-1-i]; + saved[i]=buf[i]*lwin[-i]; } saved_start=0; } else { saved_start=(vc->blocksize_1-vc->blocksize_0)/4; + buf += vc->blocksize_1/2; for(i=0;i<saved_start;++i) { - saved[i]=buf[vc->blocksize_1/2+i]; + saved[i]=buf[i]; } + swin += vc->blocksize_0/2-1; for(i=0;i<vc->blocksize_0/2;++i) { - saved[saved_start+i]=buf[vc->blocksize_1/2+saved_start+i]*swin[vc->blocksize_0/2-1-i]; + saved[saved_start+i]=buf[saved_start+i]*swin[-i]; } } } else { @@ -1375,8 +1382,10 @@ static int vorbis_parse_audio_packet(vorbis_context *vc) { } retlen=saved_start+vc->blocksize_0/2; // -- save + buf += vc->blocksize_0/2; + swin += vc->blocksize_0/2-1; for(i=0;i<vc->blocksize_0/2;++i) { - saved[i]=buf[vc->blocksize_0/2+i]*swin[vc->blocksize_0/2-1-i]; + saved[i]=buf[i]*swin[-i]; } saved_start=0; } @@ -1422,11 +1431,12 @@ static int vorbis_decode_frame(AVCodecContext *avccontext, for(i=0;i<len;++i) { int_fast32_t tmp= ((int32_t*)vc->ret)[i]; - if(tmp > 0x43c07fff) - tmp= 32767; - else if(tmp < 0x43bf8000) - tmp= -32768; - ((int16_t*)data)[i]=tmp; + if(tmp & 0xf0000){ +// tmp= (0x43c0ffff - tmp)>>31; //ask gcc devs why this is slower + if(tmp > 0x43c0ffff) tmp= 0xFFFF; + else tmp= 0; + } + ((int16_t*)data)[i]=tmp - 0x8000; } *data_size=len*2; |