I had previously used this ffmpeg WASM port (https://github.com/Kagami/ffmpeg.js) and hadn't seen the one you're using before (https://github.com/ffmpegjs/ffmpeg.js). Any thoughts on their pros & cons?
Also, I'm the maintainer of the awesome-ffmpeg list - mind if I add this to there?
Overall ffmpegjs/ffmpeg.js has been really nice. I would honestly prefer less API: they wrapped everything into a worker and made their own API calls, but I'd prefer the raw Emscripten filesystem and no worker/proxying. Then maybe a second library that wraps it up would be nice for ease of use.
I ran into one issue where the memory being used by ffmpeg was too great for running on an Android Pixel 3a (malloc failed). I split up the video encoding into 30 frame chunks. I don't think this was related to ffmpegjs/ffmpeg.js however.
This is wonderfully executed hack, for any feedback all I would have are nits. Well done, you have made my Friday.