Hello,
When I convert a video's frame rate, will the audio automaticall be adjusted, or do I need to make adjustments to the audio?
Will the runtime of the video shorten?
Thank you
There are two different video filters which alter frame rate – "Change FPS" and "Resample FPS". The former alters the duration, the latter does not. Therefore, you need to take care of audio only if you use "Change FPS". If you do, you need to actively modify all audio tracks, there is no "automatic geabox" here.
Unless you convert between "Film" (24000/1001 ~ 23.976 fps) and "PAL" (25000/1000 = 25 fps), which is covered by the "frame rate change" option in audio filters which needs to be explicitely enabled by the user, audio needs to be exported (preferably as PCM), edited with an external application like Audacity wave editor and subsequently re-imported (also preferably as PCM, to be re-compressed in Avidemux) as an external audio track.