[thegoleffect]

I no longer see the warning on the readme, but, this relies on SharedArrayBuffer, so it is not currently supported on mobile (except Firefox for android) and some other browsers: https://caniuse.com/sharedarraybuffer

[ObsoleteNerd]

I get this when I visit the OP link:

> Your browser doesn't support SharedArrayBuffer, thus ffmpeg.wasm cannot execute. Please use latest version of Chromium or any other browser supports SharedArrayBuffer.

[pteraspidomorph]

According to caniuse some headers are necessary for it to work on Firefox. I guess the developer has to fix the demo.

[JeromeWu]

It is on the last line of the Installation section, but yes, ffmpeg.wasm still replies on SharedArrayBuffer for multi-threading.