[FFmpeg-user] Detect interlaced video

[Oliver Fromme]

Carl Eugen Hoyos wrote:
 > Oliver Fromme <oliver <at> fromme.com> writes:
 > 
 > > Actually I had hoped that there is a flag somewhere 
 > > on the DVD, either in the meta data or in the MPEG2 
 > > stream itself, indicating whether a title is 
 > > interlaced or progressive.
 > 
 > The flag tells you if the stream was encoded using 
 > mpeg2video interlaced or mpeg2video progressive, but 
 > to decide whether or mot to deinterlace a video, only 
 > the actual content is relevant: Progressive content 
 > is often encoded as interlaced and it is of course 
 > possible (although unlikely) that interlaced content 
 > is encoded using progressive frames.

Ok, thanks for the explanation.  So I will just use the
idet filter to determine whether deinterlacing is required.

By the way, does it hurt to use the yadif filter on frames
that are not interlaced?

I came across an old DVD once that contained titles that
consisted of some scenes that were interlaced and some that
were not.  I ran yadif over the complete titles, and I
think it didn't hurt the non-interlaced scenes, but I'm
not 100% certain.  If it _does_ hurt, what is the best way
to handle such mixed material?

Best regards
   Oliver

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