[FFmpeg-user] Reversing PAL->NTSC telecining.

Carl Eugen Hoyos cehoyos at ag.or.at
Tue Jan 7 16:16:25 CET 2014

Nicholas Robbins <nickrobbins <at> yahoo.com> writes:

> ffmpeg -probesize 2G -analyzeduration 2G -i test.vob 
> -sn -an -c:v copy  /tmp/testing/out.mkv

> ffmpeg version 2.0.2

This looks old (and iirc and you reported a problem 
with fieldmatch and decimate on mplayer-users, then 
this is the reason). Please always test current git 
head before reporting a problem on this mailing list.

> Can't write packet with unknown timestamp
> av_interleaved_write_frame(): Invalid argument

This needs -fflags2 +genpts (an input option).


> So you are saying that fieldmatch doesn't label the 
> frames as interlaced if it can't fix them, so yadif 
> won't don anything in this command.

No, on the contrary, but I think you should only use 
this additional feature of fieldmatch if needed.

(And for the only source I know where it may be useful, 
it indeed does not work correctly. But it probably 
works if a necessary frame was simply removed from the 
stream before transmission, this is called "bad edit".)

> So my choices are, leave all the interlaced frames or 
> yadif the whole video. Is that correct?

Do you see any interlaced frames after using fieldmatch?
If not, please don't use yadif, if yes, consider 
providing a sample.

Carl Eugen

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