[FFmpeg-devel] [PATCH 2/4] h261dec: Optimize new RL_VLC decoding.
Reimar Döffinger
Reimar.Doeffinger at gmx.de
Sun Aug 31 16:48:42 CEST 2014
Signed-off-by: Reimar Döffinger <Reimar.Doeffinger at gmx.de>
---
libavcodec/h261dec.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/libavcodec/h261dec.c b/libavcodec/h261dec.c
index 5f0eb59..f286d23 100644
--- a/libavcodec/h261dec.c
+++ b/libavcodec/h261dec.c
@@ -318,27 +318,25 @@ static int h261_decode_block(H261Context *h, int16_t *block, int n, int coded)
/* The remaining combinations of (run, level) are encoded with a
* 20-bit word consisting of 6 bits escape, 6 bits run and 8 bits
* level. */
- run = SHOW_UBITS(re, &s->gb, 6);
+ run = SHOW_UBITS(re, &s->gb, 6) + 1;
SKIP_CACHE(re, &s->gb, 6);
level = SHOW_SBITS(re, &s->gb, 8);
SKIP_COUNTER(re, &s->gb, 6 + 8);
} else if (level == 0) {
break;
} else {
- run--;
if (SHOW_UBITS(re, &s->gb, 1))
level = -level;
SKIP_COUNTER(re, &s->gb, 1);
}
i += run;
- if (i >= 64) {
+ if (i > 64) {
av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d\n",
s->mb_x, s->mb_y);
return -1;
}
- j = scan_table[i];
+ j = scan_table[i-1];
block[j] = level;
- i++;
}
CLOSE_READER(re, &s->gb);
}
--
2.1.0
More information about the ffmpeg-devel
mailing list