}
// Decode the audio packet using the functions above
+#define BIAS 384
static int vorbis_parse_audio_packet(vorbis_context *vc) {
GetBitContext *gb=&vc->gb;
// -- overlap/add
if (previous_window) {
for(k=j, i=0;i<vc->blocksize_1/2;++i, k+=step) {
- ret[k]=saved[i]+buf[i]*lwin[i];
+ ret[k]=saved[i]+buf[i]*lwin[i]+BIAS;
}
retlen=vc->blocksize_1/2;
} else {
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];
+ ret[k]=saved[i]+buf[(vc->blocksize_1-vc->blocksize_0)/4+i]*swin[i]+BIAS;
}
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];
+ ret[k]=buf[vc->blocksize_0/2+(vc->blocksize_1-vc->blocksize_0)/4+i]+BIAS;
}
retlen=vc->blocksize_0/2+(vc->blocksize_1-vc->blocksize_0)/4;
}
} else {
// --overlap/add
for(k=j, i=0;i<saved_start;++i, k+=step) {
- ret[k]=saved[i];
+ ret[k]=saved[i]+BIAS;
}
for(i=0;i<vc->blocksize_0/2;++i, k+=step) {
- ret[k]=saved[saved_start+i]+buf[i]*swin[i];
+ ret[k]=saved[saved_start+i]+buf[i]*swin[i]+BIAS;
}
retlen=saved_start+vc->blocksize_0/2;
// -- save
AV_DEBUG("parsed %d bytes %d bits, returned %d samples (*ch*bits) \n", get_bits_count(gb)/8, get_bits_count(gb)%8, len);
for(i=0;i<len;++i) {
- int_fast32_t tmp;
-
- tmp=vc->ret[i]*32768;
- if (tmp>32767) tmp=32767;
- if (tmp<-32768) tmp=-32768;
+ 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;
}
+
*data_size=len*2;
return buf_size ;