[Libav-user] Encoding with variable frame rate
Carl Eugen Hoyos
cehoyos at ag.or.at
Mon May 20 16:27:55 CEST 2013
Robert Krüger <krueger at ...> writes:
> >> > FFmpeg's mov muxer does not support vfr.
> >> Do you know what exactly is missing?
> > No, but it was discussed recently on irc.
(Maybe not recently or not on irc, sorry.)
> OK, I am asking because in the code there is neither
> a comment regarding that nor is it obvious that a
> frame rate is used anywhere with the exception of
> timecode tracks where it is needed for obvious
> reasons and in mov_write_uuidprof_tag, which is
> only used in PSP mode and the Quicktime spec AFAIK
> offers no means of specifying a constant frame
> rate explicitly.
The point is that it will not try to write vfr files
because the relevant flag is not set.
> It will just result in a time-to-sample table that
> looks differently if it is constant. But, of course,
> there may be not so obvious places in the code,
> where constant frame rate is assumed and for people
> considering working on the mov muxer, this would be
> valuable information. That's why I am asking. Is
> IRC traffic archived publicly somewhere?
But I searched hard and couldn't find the (short)
discussion I thought to remember ;-(
This might help you:
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