[FFmpeg-user] Questions about w3fdif deinterlacing

[Carl Eugen Hoyos]

Christian Ebert <blacktrash <at> gmx.net> writes:

> * Carl Eugen Hoyos on Saturday, January 18, 2014
> > Seth Parker <csparker247 <at> gmail.com> writes:
> >> So idet DOES report frame info to w3fdif?
> > 
> > Yes (and to yadif and any other interested 
> > filter.)
> 
> Doesn't yadif have its own detection:
> yadif=deint=interlaced
> ?

No, it does not have detection.

MPEG-2 streams contain information about interlaced / 
non-interlaced which is used by yadif if you set it so.
The problem is that (where I live, and - I suspect - 
where you live) *all* dvb streams are marked as 
"interlaced" (because they are encoded with the 
hardware encoder set to "interlaced"), no matter if 
they are progressive (imagine a movie or soap) or 
interlaced (sports, news).

> and parity=auto is its default?

The situation is similar although it should usually 
be correct, real (dvd) streams with incorrect 
parity information exist though.

> Why would I want to run idet before yadif?

I always trust my eyes, if you have to automate, 
idet is the best / only possibility you have.
Don't forget that it does not work well with 
telecined streams.

Carl Eugen