Slowing down video with Avidemux?

[AshleyQuick]

I've tried both the change FPS and Resample FPS filters (also changed the Video Output from Copy) and it's still the same length. I want the video to be slower so that the length increases by a few seconds.

Can Avidemux handle this or should I look to something else?

[manono]

I don't use AviDemux and I'm sure someone that does will come along to answer your question.

But it's a simple matter to slow a video by changing the framerate using AviSynth. For example, if the video is 23.976fps, by adding the line:

AssumeFPS(20)

to the script, the video is slowed to 20fps. And depending on the type of video, you can do it in other ways without even reencoding the video (AviSynth requires reencoding).

[AshleyQuick]

I don't use AviDemux and I'm sure someone that does will come along to answer your question.

But it's a simple matter to slow a video by changing the framerate using AviSynth. For example, if the video is 23.976fps, by adding the line:

AssumeFPS(20)

to the script, the video is slowed to 20fps. And depending on the type of video, you can do it in other ways without even reencoding the video (AviSynth requires reencoding).

I downloaded AviSynth but I don't know how to open it or how to add that line.

[davexnet]

Avisynth is not an application you open. It runs in the background as a frameserver and it's actions are controlled
by a script which can be opened by any app that accepts these scripts, such as ripbot264, virtualdub filtermod and many more

I tried avidemux and it slows down the video just fine. I loaded a short PAL clip (25 fps) and set "copy" to mpeg4 AVC,
set video/configure to general tab/basic/very fast, and added the filter Change FPS and set destination frame rate to 23.96

For audio I chose aac, and under filter I chose frame rate change Pal To Film

Successfully created an NTSC frame rate (film) conversion

[AshleyQuick]

Those settings in avidemux worked, thanks!