[FFmpeg-user] Treating video frame-based instead of time-based

[Wolfgang Hugemann]

> I may misunderstand but FFmpeg treats all video as frame-based.

Sorry, I posed the question wrong. I meant that I would like to use a
frame-count-based scale instead of a time-based scale, in the way that a
genuine frame server like AVIsynth does.

>> * Could I (easily) extract every nth frame from a video (in order to
>> dump the result as JPEGs)?
> See the select or the fps filter or use a low output frame rate (which
> forces frame drops).

I fear that this would provoke rounding errors, especially with NTSC's
29,97 fps. To the contrast, AVIsynth's "SelectEvery(5)" is bullet-proof:
It takes every 5th frame (in presentation order), no matter what.

...

I take from your answer that this approach is just impossible with
FFmpeg at the moment.

Wolfgang Hugemann