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Original Commit: r39 | ods15 | 2006-09-23 09:36:11 +0300 (Sat, 23 Sep 2006) | 2 lines

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add window function

Originally committed as revision 6447 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Oded Shimon 2006-10-02 05:56:25 +00:00
parent 6b03d096dc
commit f71b6d7072
1 changed files with 51 additions and 0 deletions
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51
libavcodec/vorbis_enc.c
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@ -98,6 +98,7 @@ typedef struct {
int blocksize[2]; // in (1<<n) format
MDCTContext mdct[2];
const float * win[2];
int have_saved;
float * saved;
float * samples;
float * floor; // also used for tmp values for mdct
@ -339,6 +340,7 @@ static void create_vorbis_context(venc_context_t * venc, AVCodecContext * avccon
venc->modes[0].blockflag = 0;
venc->modes[0].mapping = 0;
venc->have_saved = 0;
venc->saved = av_malloc(sizeof(float) * venc->channels * (1 << venc->blocksize[1]) / 2);
venc->samples = av_malloc(sizeof(float) * venc->channels * (1 << venc->blocksize[1]));
venc->floor = av_malloc(sizeof(float) * venc->channels * (1 << venc->blocksize[1]) / 2);
@ -611,6 +613,53 @@ static int vorbis_encode_init(AVCodecContext * avccontext)
return 0;
}
static int window(venc_context_t * venc, signed short * audio, int samples) {
int i, j, channel;
const float * win = venc->win[0];
int window_len = 1 << (venc->blocksize[0] - 1);
// FIXME use dsp
if (!venc->have_saved && !samples) return 0;
if (venc->have_saved) {
for (channel = 0; channel < venc->channels; channel++) {
memcpy(venc->samples + channel*window_len*2, venc->saved + channel*window_len, sizeof(float)*window_len);
}
} else {
for (channel = 0; channel < venc->channels; channel++) {
memset(venc->samples + channel*window_len*2, 0, sizeof(float)*window_len);
}
}
if (samples) {
for (channel = 0; channel < venc->channels; channel++) {
float * offset = venc->saved + channel*window_len*2 + window_len;
j = channel;
for (i = 0; i < samples; i++, j += venc->channels)
offset[i] = audio[j] / 32768. * win[window_len - i];
}
} else {
for (channel = 0; channel < venc->channels; channel++) {
memset(venc->samples + channel*window_len*2 + window_len, 0, sizeof(float)*window_len);
}
}
for (channel = 0; channel < venc->channels; channel++) {
ff_mdct_calc(&venc->mdct[0], venc->coeffs + channel*window_len, venc->samples + channel*window_len*2, venc->floor/*tmp*/);
}
if (samples) {
for (channel = 0; channel < venc->channels; channel++) {
j = channel;
for (i = 0; i < samples; i++, j += venc->channels)
venc->saved[i] = audio[j] / 32768. * win[i];
}
venc->have_saved = 1;
} else {
venc->have_saved = 0;
}
return 1;
}
static int vorbis_encode_frame(AVCodecContext * avccontext, unsigned char * packets, int buf_size, void *data)
{
@ -622,6 +671,8 @@ static int vorbis_encode_frame(AVCodecContext * avccontext, unsigned char * pack
PutBitContext pb;
int i;
if (!window(venc, audio, samples)) return 0;
init_put_bits(&pb, packets, buf_size);
put_bits(&pb, 1, 0); // magic bit