+ VideoFrame const length = (double (_format_context->duration) / AV_TIME_BASE) * video_frame_rate();
+ return max (1, length);
+}
+
+string
+FFmpegExaminer::audio_stream_name (AVStream* s) const
+{
+ stringstream n;
+
+ n << stream_name (s);
+
+ if (!n.str().empty()) {
+ n << "; ";
+ }
+
+ n << s->codec->channels << " channels";
+
+ return n.str ();
+}
+
+string
+FFmpegExaminer::subtitle_stream_name (AVStream* s) const
+{
+ stringstream n;
+
+ n << stream_name (s);
+
+ if (n.str().empty()) {
+ n << _("unknown");
+ }
+
+ return n.str ();