Apply a filter to specific section of video

[eumagga0x2a]

Is CRF 0 not lossless on x264?

Yes, but the performance is an order of magnitude worse than with Ut. In any case, disable B-frames for all intermediate steps.

The audio track is being replaced with music, I will edit the video to sync it with the music.
Is that a scenario that gets complicated?

IMHO yes, this is quite a challenge.

[Gew]

Thread necromancy, check! ✅

Anyways, any plans on adding a filter-only-on-part-of-project button/function/feature? It could come in much handy, like me right now for instance, trying to put crop on only a small part of the video, running latest Avidemux under Windows 10. Of course there are work-arounds, running stream-copy-and-save on parts of the project and then outputting using same (e.g. x264) parameters and then pulling a an append/merge on parts, but not having to do all these steps would be awesome.

[Geo_log]

trying to put crop on only a small part of the video

Crop filter cannot be partitionized because it changes the dimensions of the video.
Use Zoom instead.

[sark]

Anyways, any plans on adding a filter-only-on-part-of-project button/function/feature?

This function/feature already exists, just not for all filters.
The Zoom filter Geo_log suggests is basically a Crop and Rescale filter combined, with the option to partialize.