+ p.push_back (UserProperty (_("Video"), _("Bits per pixel"), raw_convert<string> (_bits_per_pixel.get ())));
+ }
+}
+
+/** Our subtitle streams have colour maps, which can be changed, but
+ * they have no way of signalling that change. As a hack, we have this
+ * method which callers can use when they've modified one of our subtitle
+ * streams.
+ */
+void
+FFmpegContent::signal_subtitle_stream_changed ()
+{
+ signal_changed (FFmpegContentProperty::SUBTITLE_STREAM);
+}
+
+vector<shared_ptr<FFmpegAudioStream> >
+FFmpegContent::ffmpeg_audio_streams () const
+{
+ vector<shared_ptr<FFmpegAudioStream> > fa;
+ BOOST_FOREACH (AudioStreamPtr i, audio->streams()) {
+ fa.push_back (dynamic_pointer_cast<FFmpegAudioStream> (i));