From 0e6fdebd0d5dafa07b4963f6b8ea7690ca124887 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Fri, 15 Sep 2023 15:08:57 +0200 Subject: [PATCH] avcodec/vp3: Simplify shuffling frames, fix crash on alloc error When decoding non-keyframes, the decoding process expects there to be two reference frames, the last one and the golden one. The existence of the golden one is checked and in case it is there, it is presumed that the last one exists as well. This assumption is wrong in case of memory allocation failure, namely in case the call to ff_thread_ref_frame() that sets the last frame fails. Fix this by actually performing a shuffle without creating new references. This can't fail and has the advantage of fewer implicit allocations. Signed-off-by: Andreas Rheinhardt --- libavcodec/vp3.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c index 81dd6535c0..98dabfc907 100644 --- a/libavcodec/vp3.c +++ b/libavcodec/vp3.c @@ -2498,19 +2498,14 @@ static int update_frames(AVCodecContext *avctx) Vp3DecodeContext *s = avctx->priv_data; int ret = 0; - /* shuffle frames (last = current) */ - ff_thread_release_ext_buffer(avctx, &s->last_frame); - ret = ff_thread_ref_frame(&s->last_frame, &s->current_frame); - if (ret < 0) - goto fail; - if (s->keyframe) { ff_thread_release_ext_buffer(avctx, &s->golden_frame); ret = ff_thread_ref_frame(&s->golden_frame, &s->current_frame); } + /* shuffle frames */ + ff_thread_release_ext_buffer(avctx, &s->last_frame); + FFSWAP(ThreadFrame, s->last_frame, s->current_frame); -fail: - ff_thread_release_ext_buffer(avctx, &s->current_frame); return ret; }