avcodec/golomb: Speed up long ur_golomb codes

Fixes: Timeout
Fixes: 10972/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FLAC_fuzzer-5707569640243200

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2018-11-09 21:50:23 +01:00
parent 3c9c9b1568
commit 6b4c9854da

View File

@ -476,15 +476,19 @@ static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit,
return buf;
} else {
int i;
for (i = 0; i < limit && SHOW_UBITS(re, gb, 1) == 0; i++) {
for (i = 0; i + MIN_CACHE_BITS <= limit && SHOW_UBITS(re, gb, MIN_CACHE_BITS) == 0; i += MIN_CACHE_BITS) {
if (gb->size_in_bits <= re_index) {
CLOSE_READER(re, gb);
return -1;
}
LAST_SKIP_BITS(re, gb, 1);
LAST_SKIP_BITS(re, gb, MIN_CACHE_BITS);
UPDATE_CACHE(re, gb);
}
SKIP_BITS(re, gb, 1);
for (; i < limit && SHOW_UBITS(re, gb, 1) == 0; i++) {
SKIP_BITS(re, gb, 1);
}
LAST_SKIP_BITS(re, gb, 1);
UPDATE_CACHE(re, gb);
if (i < limit - 1) {
if (k) {