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adpcm_ima_wav: process channel-interleaved blocks sequentially rather than simultaneously.

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Speeds up the ADPCM IMA WAV decoder by 15-20% overall.
This commit is contained in:
Justin Ruggles 2011-09-09 16:26:11 -04:00
parent 7c287b18a0
commit 119974b164
1 changed files with 11 additions and 7 deletions
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18
libavcodec/adpcm.c
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@ -448,14 +448,18 @@ static int adpcm_decode_frame(AVCodecContext *avctx,
}
while(src < buf + buf_size){
for(m=0; m<4; m++){
for(i=0; i<=st; i++)
*samples++ = adpcm_ima_expand_nibble(&c->status[i], src[4*i] & 0x0F, 3);
for(i=0; i<=st; i++)
*samples++ = adpcm_ima_expand_nibble(&c->status[i], src[4*i] >> 4 , 3);
src++;
for (i = 0; i < avctx->channels; i++) {
cs = &c->status[i];
for (m = 0; m < 4; m++) {
uint8_t v = *src++;
*samples = adpcm_ima_expand_nibble(cs, v & 0x0F, 3);
samples += avctx->channels;
*samples = adpcm_ima_expand_nibble(cs, v >> 4 , 3);
samples += avctx->channels;
}
samples -= 8 * avctx->channels - 1;
}
src += 4*st;
samples += 7 * avctx->channels;
}
break;
case CODEC_ID_ADPCM_4XM: