-Butler::Butler (shared_ptr<Player> player, shared_ptr<Log> log, AudioMapping audio_mapping, int audio_channels)
+/** @param pixel_format Pixel format functor that will be used when calling ::image on PlayerVideos coming out of this
+ * butler. This will be used (where possible) to prepare the PlayerVideos so that calling image() on them is quick().
+ * @param aligned Same as above for the `aligned' flag.
+ * @param fast Same as above for the `fast' flag.
+ */
+Butler::Butler (
+ shared_ptr<Player> player,
+ shared_ptr<Log> log,
+ AudioMapping audio_mapping,
+ int audio_channels,
+ function<AVPixelFormat (AVPixelFormat)> pixel_format,
+ bool aligned,
+ bool fast
+ )