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ffmpeg.wasm-core
Commit 29df2599 authored by Michael Niedermayer's avatar Michael Niedermayer
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optimizing non_intra ac coeff decode 

Originally committed as revision 4140 to svn://svn.ffmpeg.org/ffmpeg/trunk
parent 6f921f31
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Showing with 52 additions and 43 deletions
libavcodec/mpeg12.c
View file @ 29df2599
......@@ -1564,45 +1564,42 @@ static inline int mpeg1_decode_block_inter(MpegEncContext *s,
const int qscale= s->qscale;
{
int v;
OPEN_READER(re, &s->gb);
i = -1;
/* special case for the first coef. no need to add a second vlc table */
UPDATE_CACHE(re, &s->gb);
v= SHOW_UBITS(re, &s->gb, 2);
if (v & 2) {
LAST_SKIP_BITS(re, &s->gb, 2);
if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
level= (3*qscale*quant_matrix[0])>>5;
level= (level-1)|1;
if(v&1)
if(GET_CACHE(re, &s->gb)&0x40000000)
level= -level;
block[0] = level;
i++;
SKIP_BITS(re, &s->gb, 2);
if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
goto end;
}
/* now quantify & encode AC coefs */
for(;;) {
UPDATE_CACHE(re, &s->gb);
GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
if(level == 127){
break;
} else if(level != 0) {
if(level != 0) {
i += run;
j = scantable[i];
level= ((level*2+1)*qscale*quant_matrix[j])>>5;
level= (level-1)|1;
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
LAST_SKIP_BITS(re, &s->gb, 1);
SKIP_BITS(re, &s->gb, 1);
} else {
/* escape */
run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
UPDATE_CACHE(re, &s->gb);
level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
if (level == -128) {
level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
} else if (level == 0) {
level = SHOW_UBITS(re, &s->gb, 8) ; LAST_SKIP_BITS(re, &s->gb, 8);
level = SHOW_UBITS(re, &s->gb, 8) ; SKIP_BITS(re, &s->gb, 8);
}
i += run;
j = scantable[i];
......@@ -1622,7 +1619,12 @@ static inline int mpeg1_decode_block_inter(MpegEncContext *s,
}
block[j] = level;
if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
break;
UPDATE_CACHE(re, &s->gb);
}
end:
LAST_SKIP_BITS(re, &s->gb, 2);
CLOSE_READER(re, &s->gb);
}
s->block_last_index[n] = i;
......@@ -1637,45 +1639,42 @@ static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *bloc
const int qscale= s->qscale;
{
int v;
OPEN_READER(re, &s->gb);
i = -1;
/* special case for the first coef. no need to add a second vlc table */
UPDATE_CACHE(re, &s->gb);
v= SHOW_UBITS(re, &s->gb, 2);
if (v & 2) {
LAST_SKIP_BITS(re, &s->gb, 2);
if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
level= (3*qscale)>>1;
level= (level-1)|1;
if(v&1)
if(GET_CACHE(re, &s->gb)&0x40000000)
level= -level;
block[0] = level;
i++;
SKIP_BITS(re, &s->gb, 2);
if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
goto end;
}
/* now quantify & encode AC coefs */
for(;;) {
UPDATE_CACHE(re, &s->gb);
GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
if(level == 127){
break;
} else if(level != 0) {
if(level != 0) {
i += run;
j = scantable[i];
level= ((level*2+1)*qscale)>>1;
level= (level-1)|1;
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
LAST_SKIP_BITS(re, &s->gb, 1);
SKIP_BITS(re, &s->gb, 1);
} else {
/* escape */
run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
UPDATE_CACHE(re, &s->gb);
level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
if (level == -128) {
level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
} else if (level == 0) {
level = SHOW_UBITS(re, &s->gb, 8) ; LAST_SKIP_BITS(re, &s->gb, 8);
level = SHOW_UBITS(re, &s->gb, 8) ; SKIP_BITS(re, &s->gb, 8);
}
i += run;
j = scantable[i];
......@@ -1691,7 +1690,12 @@ static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *bloc
}
block[j] = level;
if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
break;
UPDATE_CACHE(re, &s->gb);
}
end:
LAST_SKIP_BITS(re, &s->gb, 2);
CLOSE_READER(re, &s->gb);
}
s->block_last_index[n] = i;
......@@ -1713,7 +1717,6 @@ static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
mismatch = 1;
{
int v;
OPEN_READER(re, &s->gb);
i = -1;
if (n < 4)
......@@ -1723,30 +1726,28 @@ static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
/* special case for the first coef. no need to add a second vlc table */
UPDATE_CACHE(re, &s->gb);
v= SHOW_UBITS(re, &s->gb, 2);
if (v & 2) {
LAST_SKIP_BITS(re, &s->gb, 2);
if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
level= (3*qscale*quant_matrix[0])>>5;
if(v&1)
if(GET_CACHE(re, &s->gb)&0x40000000)
level= -level;
block[0] = level;
mismatch ^= level;
i++;
SKIP_BITS(re, &s->gb, 2);
if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
goto end;
}
/* now quantify & encode AC coefs */
for(;;) {
UPDATE_CACHE(re, &s->gb);
GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
if(level == 127){
break;
} else if(level != 0) {
if(level != 0) {
i += run;
j = scantable[i];
level= ((level*2+1)*qscale*quant_matrix[j])>>5;
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
LAST_SKIP_BITS(re, &s->gb, 1);
SKIP_BITS(re, &s->gb, 1);
} else {
/* escape */
run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
......@@ -1769,7 +1770,12 @@ static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
mismatch ^= level;
block[j] = level;
if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
break;
UPDATE_CACHE(re, &s->gb);
}
end:
LAST_SKIP_BITS(re, &s->gb, 2);
CLOSE_READER(re, &s->gb);
}
block[63] ^= (mismatch & 1);
......@@ -1792,29 +1798,27 @@ static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
/* special case for the first coef. no need to add a second vlc table */
UPDATE_CACHE(re, &s->gb);
v= SHOW_UBITS(re, &s->gb, 2);
if (v & 2) {
LAST_SKIP_BITS(re, &s->gb, 2);
if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
level= (3*qscale)>>1;
if(v&1)
if(GET_CACHE(re, &s->gb)&0x40000000)
level= -level;
block[0] = level;
i++;
SKIP_BITS(re, &s->gb, 2);
if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
goto end;
}
/* now quantify & encode AC coefs */
for(;;) {
UPDATE_CACHE(re, &s->gb);
GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
if(level == 127){
break;
} else if(level != 0) {
if(level != 0) {
i += run;
j = scantable[i];
level= ((level*2+1)*qscale)>>1;
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
LAST_SKIP_BITS(re, &s->gb, 1);
SKIP_BITS(re, &s->gb, 1);
} else {
/* escape */
run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
......@@ -1832,7 +1836,12 @@ static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
}
block[j] = level;
if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
break;
UPDATE_CACHE(re, &s->gb);
}
end:
LAST_SKIP_BITS(re, &s->gb, 2);
CLOSE_READER(re, &s->gb);
s->block_last_index[n] = i;
return 0;
......
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