[FFmpeg-user] (de)-interlacing question

[Toerless Eckert]

1. When i use ffmpeg's "-deinterlace" CLI option, which deinterlacer
   is used ? Eg: in ffmpeg's documentation i can only find info about
   a bunch of deinterlacers that are not called "deinterlace" on the CLI
   and i think all of these have to be parameters to -vf (video filter).

2. The 50i material i get from TV nowadays seems to be 720 at 25p material
   that was motion interpolated to 50p, scaled down and then sent interlaced.
   Aka: every second field is probably just invented by motion interpolation.
   Which is quite annoying because IMHO this makes 50% of the bits mostly
   fabrication instead of actual source bits.

   What's logically the best deinterlacing option before encoding for
   this type of material. Eg: Am am lucky, all bottom fields are interlaced,
   i throw them away, and interpolate the missing lines. Wats the ffmpeg
   CLI options to best do this ? Anything better ? Eg: Any encoding value i
   can get out of those motion interpolated fields ?

Thanks