Video filter Yadif

This is a port of Yadif (Yet Another De-Interlacing Filter) from MPlayer. The original filter was written by Michael Niedermayer. Later it was ported to Avisynth by Fizick and finally ported to Avidemux by Mean.

For telecined DVD sources specifically, Decomb Telecide is strongly recommended instead of this filter.

When compared with other deinterlacing filters available in Avidemux, some users and testers believe this is the best general purpose deinterlacing filter. Comparison test showed a consistent high quality of interlaced image blending with very little artifacting while maintain a smooth playback and individual frame picture. It also has the side benefit of being remarkably fast. It has also been found to work very well with MythTV video that has not been deinterlaced at all, producing nice finalized film.

This deinterlacing filter checks pixels of previous, current and next frames to re-create the missed field by some local adaptive method (edge-directed interpolation) and uses spatial check to prevent most artifactes. This filter is known to give pretty nice results with a wide range of sources, while being significant faster than TDeint.

• Mode: This setting controls the Deinterlacing Method to be used. You can choose between 4 modes:
  • Temporal & Spatial Check: This setting will keep the number of frames. So an interlaced video with 25 fps will be converted to a progressive video with 25 fps. You should use this setting if you want to keep the framerate of your video as-is. Unfortunately motion might not look fluid in this mode, but this applies to all deinterlacing filters that keep the framerate.
  • Bob, Temporal & Spatial Check: This setting will double the number of frames. So an interlaced video with 25 fps will be converted to a progressive video with 50 fps. You should use this mode if you want to double the framerate of your video. In this mode you can get almost perfectly fluid motion, but the video file will be harder to compress (about twice in size compared to first mode) and require more CPU power for proper playback.
  • Skip Spatial Temporal Check: This mode works exactly like the first mode, except it will skip certain calculations. So this mode will save some encoding time at the cost of some visual quality.
  • Bob, Skip Spatial Temporal Check: This mode works exactly like the second mode, except it will skip certain calculations. So this mode will save some encoding time at the cost of some visual quality.

• Order: This setting specifies the Field Order of the video and has to be set according to your input video. If you choose the wrong Field Order, you will get horrible results. So you have to make sure, it is set correctly. Every time! There is an easy way to check whether the selected Field Order is correct (or not): Use one of the “bob” modes (second or fourth mode) for preview. If you see the video jumping back and forth all the time, then the selected Field Order is wrong! Otherwise your setting should be okay.

Further information and discussion can be found at Doom9's forum.