Speed up video to restore original playback speed?

[nekrosoft13]

Not sure if this is the right place in the forum to ask.

Is it possible to speed up video playback to restore original playback speed? without screwing up video?

some TV networks i noticed speed up TV shows so they can fit more commercials, so instead of the original 44min, its now 41min.

[manono]

Is it possible to speed up video playback to restore original playback speed?

Wouldn't you want to slow it down to restore the original speed? 41 minutes back to the original 44, to use your example.

[nekrosoft13]

yes you are right, sorry bad wording

[manono]

So, you set a lower framerate than what it already has. That can be done with some videos formats, but it'll throw the audio out of synch so what's the point?

[Cornucopia]

can be done, but not without loss, as the networks either do that through editing, or through time compression which BLENDS frames, so slowing down won't get rid of the blends, and could very well add more if you don't do it correctly. And as was mentioned, the audio would need to be correspondingly time-expanded also as well to maintain sync (though audio is MUCH easier to do in that respect).

Scott

[manono]

...or through time compression which BLENDS frames...

Or time compresses by removing fields. I didn't even go into that aspect of it (that more often than not the video isn't just speeded up) because undoing time compression by someone that can't figure out how it was done in the first place is useless because more often than not he'll get it wrong.

If he wants to provide a short 10-second sample of something, we could offer more informed advice.

[manono]

I use the AVISynth AssumeFPS(24) (or 23.976 if for DVD) and slow the audio to match.