mpegvideoparse: do not set delta unit flag on unknown frame type

When encoding an image to mpeg2 video, with something like:
  gst-launch-1.0 encodebin name=e profile=mpegpsmux:video/mpeg,mpegversion=2,systemstream=false ! \
                 filesink location=sample.mpg filesrc num-buffers=1 blocksize=$(stat -c%s sample.png) \
                 location=sample/dts.png ! pngdec ! e.
The only frame's type is set to an invalid value 0
The consequence is that mpegvideoparse sets the delta unit flag on the buffer because
it is not an I frame, then decodebin3 drops this only frame because the delta
unit flag is set and the decoder receives eos before it was able to receive any
encoded data

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7876>

diff --git a/subprojects/gst-plugins-bad/gst/videoparsers/gstmpegvideoparse.c b/subprojects/gst-plugins-bad/gst/videoparsers/gstmpegvideoparse.c
index 5132bf756982ee9d67c877c16ac976e1d17e6de3..bb09d026b91b4ad99c7d9d397597bae74f2e5d45 100644 (file)
--- a/subprojects/gst-plugins-bad/gst/videoparsers/gstmpegvideoparse.c
+++ b/subprojects/gst-plugins-bad/gst/videoparsers/gstmpegvideoparse.c
@@ -931,7 +931,7 @@ gst_mpegv_parse_parse_frame (GstBaseParse * parse, GstBaseParseFrame * frame)
 
   if (G_UNLIKELY (mpvparse->pichdr.pic_type == GST_MPEG_VIDEO_PICTURE_TYPE_I))
     GST_BUFFER_FLAG_UNSET (buffer, GST_BUFFER_FLAG_DELTA_UNIT);
-  else
+  else if (mpvparse->pichdr.pic_type != 0)
     GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_DELTA_UNIT);
 
   /* maybe only sequence in this buffer, though not recommended,