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ffmpeg.wasm-core
Commit d94728c3 authored by Michael Niedermayer's avatar Michael Niedermayer
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cleanup 

Originally committed as revision 2684 to svn://svn.ffmpeg.org/ffmpeg/trunk
parent 821e46f4
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Showing with 29 additions and 71 deletions
libavcodec/adpcm.c
View file @ d94728c3
......@@ -299,7 +299,7 @@ static int adpcm_decode_init(AVCodecContext * avctx)
return 0;
}
static inline short adpcm_ima_expand_nibble(ADPCMChannelStatus *c, char nibble)
static inline short adpcm_ima_expand_nibble(ADPCMChannelStatus *c, char nibble, int shift)
{
int step_index;
int predictor;
......@@ -315,34 +315,7 @@ static inline short adpcm_ima_expand_nibble(ADPCMChannelStatus *c, char nibble)
/* perform direct multiplication instead of series of jumps proposed by
* the reference ADPCM implementation since modern CPUs can do the mults
* quickly enough */
diff = ((2 * delta + 1) * step) >> 3;
predictor = c->predictor;
if (sign) predictor -= diff;
else predictor += diff;
CLAMP_TO_SHORT(predictor);
c->predictor = predictor;
c->step_index = step_index;
return (short)predictor;
}
static inline short adpcm_4xa_expand_nibble(ADPCMChannelStatus *c, char nibble)
{
int step_index;
int predictor;
int sign, delta, diff, step;
step = step_table[c->step_index];
step_index = c->step_index + index_table[(unsigned)nibble];
if (step_index < 0) step_index = 0;
else if (step_index > 88) step_index = 88;
sign = nibble & 8;
delta = nibble & 7;
diff = (delta*step + (step>>1))>>3; // difference to code above
diff = ((2 * delta + 1) * step) >> shift;
predictor = c->predictor;
if (sign) predictor -= diff;
else predictor += diff;
......@@ -505,9 +478,9 @@ static int adpcm_decode_frame(AVCodecContext *avctx,
samples++;
for(m=32; n>0 && m>0; n--, m--) { /* in QuickTime, IMA is encoded by chuncks of 34 bytes (=64 samples) */
*samples = adpcm_ima_expand_nibble(cs, src[0] & 0x0F);
*samples = adpcm_ima_expand_nibble(cs, src[0] & 0x0F, 3);
samples += avctx->channels;
*samples = adpcm_ima_expand_nibble(cs, (src[0] >> 4) & 0x0F);
*samples = adpcm_ima_expand_nibble(cs, (src[0] >> 4) & 0x0F, 3);
samples += avctx->channels;
src ++;
}
......@@ -524,44 +497,29 @@ static int adpcm_decode_frame(AVCodecContext *avctx,
if (avctx->block_align != 0 && buf_size > avctx->block_align)
buf_size = avctx->block_align;
// XXX: do as per-channel loop
cs = &(c->status[0]);
cs->predictor = (*src++) & 0x0FF;
cs->predictor |= ((*src++) << 8) & 0x0FF00;
if(cs->predictor & 0x8000)
cs->predictor -= 0x10000;
CLAMP_TO_SHORT(cs->predictor);
// XXX: is this correct ??: *samples++ = cs->predictor;
cs->step_index = *src++;
if (cs->step_index < 0) cs->step_index = 0;
if (cs->step_index > 88) cs->step_index = 88;
if (*src++) av_log(avctx, AV_LOG_ERROR, "unused byte should be null !!\n"); /* unused */
if (st) {
cs = &(c->status[1]);
cs->predictor = (*src++) & 0x0FF;
cs->predictor |= ((*src++) << 8) & 0x0FF00;
for(i=0; i<avctx->channels; i++){
cs = &(c->status[i]);
cs->predictor = *src++;
cs->predictor |= (*src++) << 8;
if(cs->predictor & 0x8000)
cs->predictor -= 0x10000;
CLAMP_TO_SHORT(cs->predictor);
// XXX: is this correct ??: *samples++ = cs->predictor;
// XXX: is this correct ??: *samples++ = cs->predictor;
cs->step_index = *src++;
cs->step_index = *src++;
if (cs->step_index < 0) cs->step_index = 0;
if (cs->step_index > 88) cs->step_index = 88;
src++; /* if != 0 -> out-of-sync */
if (*src++) av_log(avctx, AV_LOG_ERROR, "unused byte should be null !!\n"); /* unused */
}
for(m=4; src < (buf + buf_size);) {
*samples++ = adpcm_ima_expand_nibble(&c->status[0], src[0] & 0x0F);
*samples++ = adpcm_ima_expand_nibble(&c->status[0], src[0] & 0x0F, 3);
if (st)
*samples++ = adpcm_ima_expand_nibble(&c->status[1], src[4] & 0x0F);
*samples++ = adpcm_ima_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F);
*samples++ = adpcm_ima_expand_nibble(&c->status[1], src[4] & 0x0F, 3);
*samples++ = adpcm_ima_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F, 3);
if (st) {
*samples++ = adpcm_ima_expand_nibble(&c->status[1], (src[4] >> 4) & 0x0F);
*samples++ = adpcm_ima_expand_nibble(&c->status[1], (src[4] >> 4) & 0x0F, 3);
if (!--m) {
m=4;
src+=4;
......@@ -585,12 +543,12 @@ static int adpcm_decode_frame(AVCodecContext *avctx,
m= (buf_size - (src - buf))>>st;
for(i=0; i<m; i++) {
*samples++ = adpcm_4xa_expand_nibble(&c->status[0], src[i] & 0x0F);
*samples++ = adpcm_ima_expand_nibble(&c->status[0], src[i] & 0x0F, 4);
if (st)
*samples++ = adpcm_4xa_expand_nibble(&c->status[1], src[i+m] & 0x0F);
*samples++ = adpcm_4xa_expand_nibble(&c->status[0], src[i] >> 4);
*samples++ = adpcm_ima_expand_nibble(&c->status[1], src[i+m] & 0x0F, 4);
*samples++ = adpcm_ima_expand_nibble(&c->status[0], src[i] >> 4, 4);
if (st)
*samples++ = adpcm_4xa_expand_nibble(&c->status[1], src[i+m] >> 4);
*samples++ = adpcm_ima_expand_nibble(&c->status[1], src[i+m] >> 4, 4);
}
src += m<<st;
......@@ -664,16 +622,16 @@ static int adpcm_decode_frame(AVCodecContext *avctx,
/* take care of the top nibble (always left or mono channel) */
*samples++ = adpcm_ima_expand_nibble(&c->status[0],
(src[0] >> 4) & 0x0F);
(src[0] >> 4) & 0x0F, 3);
/* take care of the bottom nibble, which is right sample for
* stereo, or another mono sample */
if (st)
*samples++ = adpcm_ima_expand_nibble(&c->status[1],
src[0] & 0x0F);
src[0] & 0x0F, 3);
else
*samples++ = adpcm_ima_expand_nibble(&c->status[0],
src[0] & 0x0F);
src[0] & 0x0F, 3);
src++;
}
......@@ -703,11 +661,11 @@ static int adpcm_decode_frame(AVCodecContext *avctx,
/* process the first predictor of the sum channel */
DK3_GET_NEXT_NIBBLE();
adpcm_ima_expand_nibble(&c->status[0], nibble);
adpcm_ima_expand_nibble(&c->status[0], nibble, 3);
/* process the diff channel predictor */
DK3_GET_NEXT_NIBBLE();
adpcm_ima_expand_nibble(&c->status[1], nibble);
adpcm_ima_expand_nibble(&c->status[1], nibble, 3);
/* process the first pair of stereo PCM samples */
diff_channel = (diff_channel + c->status[1].predictor) / 2;
......@@ -716,7 +674,7 @@ static int adpcm_decode_frame(AVCodecContext *avctx,
/* process the second predictor of the sum channel */
DK3_GET_NEXT_NIBBLE();
adpcm_ima_expand_nibble(&c->status[0], nibble);
adpcm_ima_expand_nibble(&c->status[0], nibble, 3);
/* process the second pair of stereo PCM samples */
diff_channel = (diff_channel + c->status[1].predictor) / 2;
......@@ -730,14 +688,14 @@ static int adpcm_decode_frame(AVCodecContext *avctx,
if (st) {
*samples++ = adpcm_ima_expand_nibble(&c->status[0],
(src[0] >> 4) & 0x0F);
(src[0] >> 4) & 0x0F, 3);
*samples++ = adpcm_ima_expand_nibble(&c->status[1],
src[0] & 0x0F);
src[0] & 0x0F, 3);
} else {
*samples++ = adpcm_ima_expand_nibble(&c->status[0],
(src[0] >> 4) & 0x0F);
(src[0] >> 4) & 0x0F, 3);
*samples++ = adpcm_ima_expand_nibble(&c->status[0],
src[0] & 0x0F);
src[0] & 0x0F, 3);
}
src++;
......
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