+ content->set_scale (VideoContentScale (Ratio::from_id ("185")));
+
+ /* Work out the first video frame index that we will be given, taking into account
+ * the difference between first video and first audio.
+ */
+ ContentTime video_delay = content->first_video().get() - content->ffmpeg_audio_streams().front()->first_audio.get();
+ if (video_delay < ContentTime ()) {
+ video_delay = ContentTime ();
+ }
+
+ Frame const first_frame = video_delay.round_up (content->video_frame_rate ()).frames_round (content->video_frame_rate ());