ffmpeg wasm implementations were slow and ugly

but i found this webm-wasm tool

it processes images input, so what i did, i extract images from video file first. this is quite fast. then encode it to webm

image extraction + encoding speed can be less than a second per frame, and this is running single threaded in web browser

ffmpeg would have taken 10 times longer

https://github.com/GoogleChromeLabs/webm-wasm

nostr:note1g6jtfv598nd8h82yu9jtze20f2jqpvkwgysev8he2pyyk4x7d9gq8awvyz