[FFmpeg-user] Keeping A/V sync during telecine

Carl Eugen Hoyos ceffmpeg at gmail.com
Sat Dec 30 20:43:03 EET 2017

2017-12-30 19:14 GMT+01:00 Phil Rhodes
<phil_rhodes-at-rocketmail.com at ffmpeg.org>:
>> The film intro is not stricly 24000/1001 frames, you can see this:
>> on the "drop" count in the status line
>> on the "29.97 fps" entry in the input section
>> (and on the mplayer status output)
> I'd be interested to know how that happened.

I don't think anything happened, we have stranger samples.
(Think of the first minutes of the Titanic dvd.)

> Ordinarily, one would assume that a file marked as being 29.97fps
> should be played at 24000/1001fps.

No, why?

> It would almost certainly have been produced with that frame rate in mind

No, nothing in the dvd specification requires cfr.

> and I'd be interested to see how any player would maintain long-term
> audio sync without playing it at that rate.

In general, keeping av-sync for vfr video is something that every video
player is able to do (possibly within some constraints, vlc for example
doesn't like very low frame rates).

Please fix your quoting, Carl Eugen

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