speed up part of video

[TheInvoker]

how do i make a video of 20min faster from min 5 to 8?

[sark]

A combination of Change FPS, and Resample FPS can speed up video, but you cannot partialize these filters, so you can only apply the effect to the whole video.

Extracting the section you need to speed up, and applying changes before remerging with the original, is really the only option. This will require reencoding the changed section twice, due to the need of near identical parameters for concatenation without reencoding.

I would normally suggest ffmpeg for this sort of thing, but the setpts filter used by ffmpeg does not support partialising either.

[sark]

This will require reencoding the changed section twice, due to the need of near identical parameters for concatenation without reencoding.

Ignore this sentence. Wasn't at my PC when I answered. You only need a single reencode.

You just need to extract each of the three sections using the same parameters. Then append and concatenate.

[TheInvoker]

but i don't want to cut the video. i already thought about that but it's too annoying and slow

i hope i could do everything at the same times and not work on 3 different pieces (Before, After, a the one i have to speed up)

[eumagga0x2a]

Don't hope, there isn't a way, especially if you want audio to remain in sync.