From fd290e2fcdd431bdce5ae7f308d22e7eaa3afa96 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 15 Jun 2026 03:38:11 +0200 Subject: [PATCH] avcodec/cbs_av1_syntax_template: reset seen_frame_header on sequence headers With this change CBS and the decoder appear to be in sync. Fixes: division by 0 Fixes: 501794431/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AV1_fuzzer-4792576644546560 Fixes: 501898692/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AV1_fuzzer-4772278394224640 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/cbs_av1_syntax_template.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/libavcodec/cbs_av1_syntax_template.c b/libavcodec/cbs_av1_syntax_template.c index f43c3a4de5..f3d84f3c05 100644 --- a/libavcodec/cbs_av1_syntax_template.c +++ b/libavcodec/cbs_av1_syntax_template.c @@ -186,10 +186,13 @@ static int FUNC(decoder_model_info)(CodedBitstreamContext *ctx, RWContext *rw, static int FUNC(sequence_header_obu)(CodedBitstreamContext *ctx, RWContext *rw, AV1RawSequenceHeader *current) { + CodedBitstreamAV1Context *priv = ctx->priv_data; int i, err; HEADER("Sequence Header"); + priv->seen_frame_header = 0; + fc(3, seq_profile, AV_PROFILE_AV1_MAIN, AV_PROFILE_AV1_PROFESSIONAL); flag(still_picture);