PR #20445 opened by DE-AI URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20445 Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20445.patch
When PARSER_FLAG_COMPLETE_FRAMES is set (e.g. in Matroska), unesc_index is not reset after the first frame, which causes subsequent frames to inherit leftover header data. This leads to incorrect keyframe marking and broken decoding. See also this bug report: https://trac.ffmpeg.org/ticket/8515 Signed-off-by: DE-AI <max.christ...@pentaxmedical.com> >From 9be0b59b547db94670319cf0073645d32dd2615c Mon Sep 17 00:00:00 2001 From: DE-AI <max.christ...@pentaxmedical.com> Date: Fri, 5 Sep 2025 15:27:01 +0000 Subject: [PATCH] vc1_parser: Reset unesc_index after extracting header with complete frames When PARSER_FLAG_COMPLETE_FRAMES is set (e.g. in Matroska), unesc_index is not reset after the first frame, which causes subsequent frames to inherit leftover header data. This leads to incorrect keyframe marking and broken decoding. See also this bug report: https://trac.ffmpeg.org/ticket/8515 Signed-off-by: DE-AI <max.christ...@pentaxmedical.com> --- libavcodec/vc1_parser.c | 1 + 1 file changed, 1 insertion(+) diff --git a/libavcodec/vc1_parser.c b/libavcodec/vc1_parser.c index a536a7bcf8..124a7a771f 100644 --- a/libavcodec/vc1_parser.c +++ b/libavcodec/vc1_parser.c @@ -179,6 +179,7 @@ static int vc1_parse(AVCodecParserContext *s, // start codes if we know it contains a complete frame and // we've already unescaped all we need of the frame header vc1_extract_header(s, avctx, unesc_buffer, unesc_index); + unesc_index = 0; break; } if (unesc_index >= UNESCAPED_THRESHOLD && !start_code_found) { -- 2.49.1 _______________________________________________ ffmpeg-devel mailing list -- ffmpeg-devel@ffmpeg.org To unsubscribe send an email to ffmpeg-devel-le...@ffmpeg.org
