[FFmpeg-user] How to drop every Nth frame?

[Andrey Aleksandrovich]

On 9/29/13, Pavel Koshevoy <pkoshevoy at gmail.com> wrote:
> On 9/28/13 4:16 AM, Andrey Aleksandrovich wrote:
>>>>> How old is your build of ffmpeg?  There was an atempo sync bug
>>>>> (http://trac.ffmpeg.org/ticket/2484), but that was fixed 5 months ago.
>>>>> If you are able to reproduce a sync issue with current ffmpeg please
>>>>> open a trac ticket.
>> Yes, I think this is it.
>> Version '1.2.3' - stable version at repositories of my system (Gentoo)
>> 0.99667 = +7.3 sec desync
>> 0.997 = +7.3
>> 0.99834 = -3.3
>> 0.99824 = -3.3
>>
>> And with latest 'N-56704-g3e0c78b' version I have:
>> 0.99667 = +4.0
>> 0.997 = +2.4
>> 0.99834 = -4.9
>> 0.99824 = -4.5
>>
>> So, seem like it is more accurate to decimals.Thanks for advise.
>>
>
> After the bug fix 5 months ago, you should expect atempo to stay in sync
> +/- 1 frame duration throughout.  An error of magnitude of 2..4 seconds
> is gigantic.  How did you arrive at the tempo scale factors that you've
> tried?  Do you know how long the track duration is and how long it
> should be?
>
>      Pavel.
> _______________________________________________
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>

No. After all experiments I've got synced a-v at the start and at the
end, but not at the middle. Maybe the origin of that video has
variable frame rate or is damaged.
Duration 01:33:21