[FFmpeg-devel] [PATCH] lavc/vvc: Always set flags for the current picture

[Frank Plowman]

ff_vvc_frame_rpl uses the flags to detect whether a frame is in use.
Therefore, in the case of a CVSS AU (RASL/GDR with
NoOutputBeforeRecoveryFlag) with ph_non_ref_pic_flag = 1, the frame
would be freed before it is used.  Fix this by always marking the
current frame with VVC_FRAME_FLAG_SHORT_REF, as is done by the HEVC
decoder.

Additionally, add an assert0 to mitigate the effects of a frame being
freed before it is used.

Signed-off-by: Frank Plowman <post at frankplowman.com>
---
 libavcodec/vvc/refs.c   | 2 +-
 libavcodec/vvc/thread.c | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/libavcodec/vvc/refs.c b/libavcodec/vvc/refs.c
index 8b7ba639a3..26a5b0b34c 100644
--- a/libavcodec/vvc/refs.c
+++ b/libavcodec/vvc/refs.c
@@ -191,7 +191,7 @@ int ff_vvc_set_new_ref(VVCContext *s, VVCFrameContext *fc, AVFrame **frame)
     fc->ref = ref;
 
     if (s->no_output_before_recovery_flag && (IS_RASL(s) || !GDR_IS_RECOVERED(s)))
-        ref->flags = 0;
+        ref->flags = VVC_FRAME_FLAG_SHORT_REF;
     else if (ph->r->ph_pic_output_flag)
         ref->flags = VVC_FRAME_FLAG_OUTPUT;
 
diff --git a/libavcodec/vvc/thread.c b/libavcodec/vvc/thread.c
index 5b01dd2d20..e87ed5b676 100644
--- a/libavcodec/vvc/thread.c
+++ b/libavcodec/vvc/thread.c
@@ -801,6 +801,8 @@ int ff_vvc_frame_wait(VVCContext *s, VVCFrameContext *fc)
 {
     VVCFrameThread *ft = fc->ft;
 
+    av_assert0(fc->ref->progress);
+
     ff_mutex_lock(&ft->lock);
 
     while (atomic_load(&ft->nb_scheduled_tasks) || atomic_load(&ft->nb_scheduled_listeners))
-- 
2.45.1