ffmpeg: Don't add sink pad template to the muxers when not needed.

If the set of caps for either audio or video is completely empty, skip
adding that pad template to the class. Some muxers only support audio-only
or video-only and otherwise end up with EMPTY caps in the pad template.

diff --git a/ext/ffmpeg/gstffmpegmux.c b/ext/ffmpeg/gstffmpegmux.c
index 55369a8..15cbaf4 100644 (file)
--- a/ext/ffmpeg/gstffmpegmux.c
+++ b/ext/ffmpeg/gstffmpegmux.c
@@ -719,6 +719,10 @@ gst_ffmpegmux_get_id_caps (enum CodecID * id_list)
     if ((t = gst_ffmpeg_codecid_to_caps (id_list[i], NULL, TRUE)))
       gst_caps_append (caps, t);
   }
+  if (gst_caps_is_empty (caps)) {
+    gst_caps_unref (caps);
+    return NULL;
+  }
 
   return caps;
 }