demux_lavf: set keyframe flag on attached pictures

Gives really funky results with PNG attachments otherwise. The main
problem is that avcodec_flush_buffers() does not fully reset the
decoder, so passing multiple PNG packets without keyframe flags will
attempt to combine the new picture with the previously decoded
contents. (Makes no sense with proper PNG - maybe this codepath is
intended for MNG or APNG.)

1 files changed, 1 insertions, 0 deletions

diff --git a/demux/demux_lavf.c b/demux/demux_lavf.c
index e7d144eb71..350fe54b66 100644
--- a/demux/demux_lavf.c
+++ b/demux/demux_lavf.c
@@ -402,6 +402,7 @@ static void handle_stream(demuxer_t *demuxer, int i)
                                                          st->attached_pic.size);
             sh->attached_picture->pts = 0;
             talloc_steal(sh, sh->attached_picture);
+            sh->attached_picture->keyframe = true;
         }
 
         sh_video->format = codec->codec_tag;