Running single threaded FFMPEG in a web worker

I know we all cried for a long time to have ffmpeg.wasm without the shared array buffer. It's now possible by forking the core and using github actions to generate the single threaded artifact.

The problem is this new core does not run in any workers at all, which is CPU blocking and freezes the UI (and sometimes the browser crashes).

I am not an expert with WASM and I am not sure if we can use web workers without having to use the sharedArrayBuffers at all?

Right now when try to use createFfmepg function in a worker (using Comlink), it says `document is not defined`, a clear sign and ffmpeg.js is not written to work in any thread other than the main one.

If this is possible at all (in the JS files), I would love to work on it too, given the right directions.

Thanks in advance.