A question came up today if I could crop a video as someone had filmed it in portrait mode creating the wrong kind of letterbox effect

Well, it is indeed possible, but rather than faff about with some GUI program, I resorted to using FFMPEG to do the work. It’s actually very easy to do, and a quick Google found the below stackexchange discussion, worked perfectly

The command is:

ffmpeg -i in.mp4 -filter:v "crop=out_w:out_h:x:y" out.mp4

So to crop an 80×60 px section starting at 200px along the x axis and 100 down along the y axis

ffmpeg -i in.mp4 -filter:v "crop=80:60:200:100" -c:a copy out.mp4

https://video.stackexchange.com/questions/4563/how-can-i-crop-a-video-with-ffmpeg

Convert MP4 to WEBM (with sound)

I frequently have issues converting videos to webm and having no sound on Mac / Safari. The one-liner below solved the issue

ffmpeg -i out.mp4 -vcodec libvpx -acodec libvorbis out.webm