From d25c945247979a88fac6bb3b7a26370262b96ef1 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 22 Jun 2018 21:45:59 +0200 Subject: [PATCH] avcodec/h264_parser: Reduce needed history for parsing mb index This fixes a bug/regression with very small packets Fixes: output_file Regression since: 0782fb6bcb32fe3ab956a99af4cc472ff81da0c2 Reported-by: Thierry Foucu Signed-off-by: Michael Niedermayer --- libavcodec/h264_parser.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/libavcodec/h264_parser.c b/libavcodec/h264_parser.c index 1a9840a62c..5f9a9c46ef 100644 --- a/libavcodec/h264_parser.c +++ b/libavcodec/h264_parser.c @@ -121,20 +121,23 @@ static int h264_find_frame_end(H264ParseContext *p, const uint8_t *buf, } state = 7; } else { + unsigned int mb, last_mb = p->parse_last_mb; + GetBitContext gb; p->parse_history[p->parse_history_count++] = buf[i]; - if (p->parse_history_count > 5) { - unsigned int mb, last_mb = p->parse_last_mb; - GetBitContext gb; - init_get_bits(&gb, p->parse_history, 8*p->parse_history_count); - p->parse_history_count = 0; - mb= get_ue_golomb_long(&gb); + init_get_bits(&gb, p->parse_history, 8*p->parse_history_count); + mb= get_ue_golomb_long(&gb); + if (get_bits_left(&gb) > 0 || p->parse_history_count > 5) { p->parse_last_mb = mb; if (pc->frame_start_found) { - if (mb <= last_mb) + if (mb <= last_mb) { + i -= p->parse_history_count - 1; + p->parse_history_count = 0; goto found; + } } else pc->frame_start_found = 1; + p->parse_history_count = 0; state = 7; } } @@ -149,7 +152,7 @@ found: pc->frame_start_found = 0; if (p->is_avc) return next_avc; - return i - (state & 5) - 5 * (state > 7); + return i - (state & 5); } static int scan_mmco_reset(AVCodecParserContext *s, GetBitContext *gb,