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Use iMDCT output scaling to simplify ffvorbis and make it slightly faster.

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Originally committed as revision 18879 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Siarhei Siamashka 2009-05-20 07:26:09 +00:00
parent 7dfed8e1dc
commit 373177949f
1 changed files with 3 additions and 19 deletions
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22
libavcodec/vorbis_dec.c
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@ -210,11 +210,6 @@ static void vorbis_free(vorbis_context *vc) {
av_free(vc->mappings[i].mux);
}
av_freep(&vc->mappings);
if(vc->exp_bias){
av_freep(&vc->win[0]);
av_freep(&vc->win[1]);
}
}
// Parse setup header -------------------------------------------------
@ -876,16 +871,6 @@ static int vorbis_parse_id_hdr(vorbis_context *vc){
vc->win[0]=ff_vorbis_vwin[bl0-6];
vc->win[1]=ff_vorbis_vwin[bl1-6];
if(vc->exp_bias){
int i, j;
for(j=0; j<2; j++){
float *win = av_malloc(vc->blocksize[j]/2 * sizeof(float));
for(i=0; i<vc->blocksize[j]/2; i++)
win[i] = vc->win[j][i] * (1<<15);
vc->win[j] = win;
}
}
if ((get_bits1(gb)) == 0) {
av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (framing flag not set). \n");
return 2;
@ -896,8 +881,8 @@ static int vorbis_parse_id_hdr(vorbis_context *vc){
vc->saved = av_mallocz((vc->blocksize[1]/4)*vc->audio_channels * sizeof(float));
vc->previous_window=0;
ff_mdct_init(&vc->mdct[0], bl0, 1, -1.0);
ff_mdct_init(&vc->mdct[1], bl1, 1, -1.0);
ff_mdct_init(&vc->mdct[0], bl0, 1, vc->exp_bias ? -(1<<15) : -1.0);
ff_mdct_init(&vc->mdct[1], bl1, 1, vc->exp_bias ? -(1<<15) : -1.0);
AV_DEBUG(" vorbis version %d \n audio_channels %d \n audio_samplerate %d \n bitrate_max %d \n bitrate_nom %d \n bitrate_min %d \n blk_0 %d blk_1 %d \n ",
vc->version, vc->audio_channels, vc->audio_samplerate, vc->bitrate_maximum, vc->bitrate_nominal, vc->bitrate_minimum, vc->blocksize[0], vc->blocksize[1]);
@ -1410,8 +1395,7 @@ static void copy_normalize(float *dst, float *src, int len, int exp_bias, float
{
int i;
if(exp_bias) {
for(i=0; i<len; i++)
((uint32_t*)dst)[i] = ((uint32_t*)src)[i] + exp_bias; // dst[k]=src[i]*(1<<bias)
memcpy(dst, src, len * sizeof(float));
} else {
for(i=0; i<len; i++)
dst[i] = src[i] + add_bias;