core: allow disabling display of "album art" in audio files

ffmpeg pretends that image attachments (such as contained in ID3v2
metadata) are video streams. It injects the attached pictures as packets
into the packet stream received with av_read_frame().

Add the --audio-display option to allow configuring whether attached
pictures should be displayed. The default behavior doesn't change
(images are displayed).

Identify video streams, that are actually image attachments, with "[P]"
in the terminal output.

Modify the default stream selection such that real video streams are
preferred over attached pictures. (This is just for robustness; I do not
know of any samples where images are added before actual video streams
and could lead to bad default stream selection with the old code.)

2 files changed, 4 insertions, 1 deletions

diff --git a/demux/demux_lavf.c b/demux/demux_lavf.c
index b3ae1d6315..7c73ac6085 100644
--- a/demux/demux_lavf.c
+++ b/demux/demux_lavf.c
@@ -438,6 +438,8 @@ static void handle_stream(demuxer_t *demuxer, AVFormatContext *avfc, int i)
         priv->vstreams[priv->video_streams] = i;
         sh_video->libav_codec_id = codec->codec_id;
         sh_video->gsh->lavf_codec_tag = lavf_codec_tag;
+        if (st->disposition & AV_DISPOSITION_ATTACHED_PIC)
+            sh_video->gsh->attached_picture = true;
         bih = calloc(sizeof(*bih) + codec->extradata_size, 1);
 
         if (codec->codec_id == CODEC_ID_RAWVIDEO) {
diff --git a/demux/stheader.h b/demux/stheader.h
index b5f11c0ecc..efcec02d7b 100644
--- a/demux/stheader.h
+++ b/demux/stheader.h
@@ -58,7 +58,8 @@ struct sh_stream {
     int lavf_codec_tag;
 
     char *title;
-    bool default_track;
+    bool default_track;         // container default track flag
+    bool attached_picture;      // stream is a picture (such as album art)
 
     // shouldn't exist type of stuff
     struct MPOpts *opts;