mirror of https://git.ffmpeg.org/ffmpeg.git
avcodec/mpeg12dec: Revert Change to mpeg2_fast_decode_block_non_intra
This fixes the speed regression from 20626f53e9
and still checks sufficiently to prevent out of allocated memory accesses
due to the index
Before:
1823 decicycles in mpeg2_fast_decode_block_non_intra, 8388493 runs, 115 skips
After:
1808 decicycles in mpeg2_fast_decode_block_non_intra, 8388494 runs, 114 skips
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
parent
6a92598e14
commit
7667afffb8
|
@ -474,7 +474,6 @@ static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
|
|||
|
||||
if (level != 0) {
|
||||
i += run;
|
||||
check_scantable_index(s, i);
|
||||
j = scantable[i];
|
||||
level = ((level * 2 + 1) * qscale) >> 1;
|
||||
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
|
||||
|
@ -486,7 +485,6 @@ static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
|
|||
level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
|
||||
|
||||
i += run;
|
||||
check_scantable_index(s, i);
|
||||
j = scantable[i];
|
||||
if (level < 0) {
|
||||
level = ((-level * 2 + 1) * qscale) >> 1;
|
||||
|
@ -497,7 +495,7 @@ 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)
|
||||
if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF || i > 63)
|
||||
break;
|
||||
|
||||
UPDATE_CACHE(re, &s->gb);
|
||||
|
|
Loading…
Reference in New Issue