This is a port of Tritical TDeint deinterlacing filter. The original file can be found at http://www.missouri.edu/~kes25c/. Discussion at http://forum.doom9.org/showthread.php?t=82264. Original filter documents at http://avisynth.org.ru/docs/english/externalfilters/tdeint.htm.
TDeint is a bi-directionally, motion adaptive, sharp deinterlacer. It can adaptively choose between using per-field and per-pixel motion adaptivity, and can use cubic interpolation, kernel interpolation (with temporal direction switching), or one of two forms of modified ELA interpolation which help to reduce “jaggy” edges in moving areas where interpolation must be used.
This port is somehow limited compared to its upstream, but has very interesting results.