[FFmpeg-user] How to deinterlace with simple blend or add

[Carl Eugen Hoyos]

MI <mi.lists.ffmpeg <at> alma.ch> writes:

> I have a video which was orginally shot progressive, 
> then encoded as interlaced.

Could you elaborate a little on what exactly was done?
(Sharing a sample as suggested by Paul is of course 
also sufficient.)

The reason I ask is that "encoded as interlaced" can 
mean many things:
The video could have been encoded in field-mode and 
signalled as interlaced (no action needed).
It could have been a 50fps video that was interlaced 
and encoded as 25i (only yadif or equivalent helps).
The fields of the progressive video could have been 
shifted, the phase filter fixes this.
I guess other possibilities exist.

Merry Christmas, Carl Eugen