drawvg is very useful. Before drawvg, I was always fine using the stable FFmpeg releases such as 8.0.1 but when I saw drawvg added to the master branch[1], I didn't want to wait for the next stable release and immediately re-built ffmpeg from master to start using it.

My main use case is modifying youtube videos of tech tutorials where the speaker overlays a video of themselves in a corner of the video. drawvg is used to blackout that area of the video. I'm sure some viewers like having a visible talking head shown on the same screen as the code but I find the constant motion of someone's lips moving and eyes blinking in my peripheral vision extremely distracting. Our vision is very tuned into paying attention to faces so the brain constantly fighting that urge so it can concentrate on the code. (A low-tech solution is to just put a yellow sticky know on the monitor to cover up the speaker but that means you can't easily resize/move the window playing the video ... so ffmpeg to the rescue.)

If the overlay was a rectangle, you can use the older drawbox filter and don't need drawvg. However, some content creaters use circles and that's where drawvg works better. Instead of creating a separate .vgs file, I just use the inline syntax like this:

  ffmpeg -i input.webm -filter_complex "[0:v]drawvg='circle 3388 1670 400 setcolor black fill'[v2];[0:a]atempo=1.5[a2]" -map "[v2]" -map "[a2]" output.mp4

That puts a black filled circle on the bottom right corner of a 4k vid to cover up the speaker. Different vids from different creators will require different x,y,radius coordinates.

(The author of the drawvg code in the git log appears to be the same as the author of this thread's article.)

[1] https://git.ffmpeg.org/gitweb/ffmpeg.git/commit/016d767c8e9d...