Many video files have used interlaced codecs, and a filter for deinterlacing them would be useful for quality.

This is already supported by GStreamer:
http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-good-plugins/html/gst-plugins-good-plugins-deinterlace.html

Il would be useful to add simple access to this GStreamer feature in MediaPlayer class in JavaFX.