[FFmpeg-cvslog] lavc/vvc: Skip enhancement layer NAL units

[Frank Plowman]

ffmpeg | branch: release/7.0 | Frank Plowman <post at frankplowman.com> | Thu Apr 18 21:26:20 2024 +0100| [cbd98447bcfd83bff98c18e144f50a603bebaf90] | committer: James Almer

lavc/vvc: Skip enhancement layer NAL units

The native VVC decoder does not yet support quality/spatial/multiview
scalability.  Bitstreams requiring this feature could cause crashes.
Patch fixes this by skipping NAL units which are not in the base layer,
warning the user while doing so.

Signed-off-by: Frank Plowman <post at frankplowman.com>
Signed-off-by: James Almer <jamrial at gmail.com>
(cherry picked from commit bb9e4ff355684b0325d1632b89baab96cc24dc51)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=cbd98447bcfd83bff98c18e144f50a603bebaf90
---

 libavcodec/vvc/vvcdec.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libavcodec/vvc/vvcdec.c b/libavcodec/vvc/vvcdec.c
index e72bb48a50..2f8b84f63b 100644
--- a/libavcodec/vvc/vvcdec.c
+++ b/libavcodec/vvc/vvcdec.c
@@ -782,6 +782,12 @@ static int decode_nal_unit(VVCContext *s, VVCFrameContext *fc, const H2645NAL *n
 
     s->temporal_id = nal->temporal_id;
 
+    if (nal->nuh_layer_id > 0) {
+        avpriv_report_missing_feature(fc->log_ctx,
+                "Decoding of multilayer bitstreams");
+        return AVERROR_PATCHWELCOME;
+    }
+
     switch (unit->type) {
     case VVC_VPS_NUT:
     case VVC_SPS_NUT: