Does not work in Firefox 79+ because SharedArrayBuffer is undefined

Describe the bug The front page says:

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

To Reproduce Steps to reproduce the behavior:

1. Go to https://ffmpegwasm.github.io/
2. Scroll down to ‘Demo’
3. See quoted error

Expected behavior As SharedArrayBuffer is available in the aforementioned versions of Firefox (on certain conditions), I think it is fair we don’t fall into the “this only works in Chrome” bane of Web applications made today, especially if the application may in fact work in Firefox and the latter only refuses to provide the object for security reasons: https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/79#JavaScript

Desktop (please complete the following information):

• OS: Windows 10 x86-64
• Browser Firefox 64-bit
• Version 81.0.1

[gzuidhof]

For those that want to host a demo/app on a domain where you can’t control the headers, with a service worker you can actually set the required COOP and COEP headers. See the coi-serviceworker repo, and this blog post that explains the approach.

It’s a bit crazy, but it’s a solution for demos hosted on Github pages.

[trybick]

I was able to fix this in Chrome for a react project on netlify by creating a netlify.toml with these headers:

[[headers]]
  for = "/*"
  [headers.values]
      Cross-Origin-Opener-Policy = "same-origin"
      Cross-Origin-Embedder-Policy = "require-corp"