[FFmpeg-user] Assumefps() equivalent in FFMPEG

[Reuben Martin]

On Tuesday, July 29, 2014 03:43:57 PM Eugene Gekhter wrote:
> Thanks for the tip. If there is audio in the file as well (super-8 sound),
> what is the recommendation for keeping that in sync with the frame rate
> change of the video?

I've never tried stretching audio with ffmpeg. I'm not really certain it's 
tooled to deal with that type of extreme re-sampling.

You might try splitting the audio off to a separate file, slow it down with 
something like rubberband (http://breakfastquay.com/), and then mux it back in 
with the video.

Also 18 fps is quite slow. If you are expecting something smooth from slowing 
it down, you're not going to get that. For that you need to use something like 
slowmovideo. (http://slowmovideo.granjow.net/)

-Reuben