From 6b4c9854daba2eac01716c3445eb68e6ab8758ba Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 9 Nov 2018 21:50:23 +0100 Subject: [PATCH] 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 --- libavcodec/golomb.h | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/libavcodec/golomb.h b/libavcodec/golomb.h index 5c25883626..fcc78f44c1 100644 --- a/libavcodec/golomb.h +++ b/libavcodec/golomb.h @@ -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) {