Stuttering audio on Chrome 89.0+ (upstream Chrome regression in ScriptProcessorNode)

[akien-mga]

Godot version:
3.2.3 stable, 3.3 RC 6
Not a Godot regression, it's a Chrome update that triggered the issue for pre-existing builds which worked fine.

OS/device including version:
Windows 10 Home Build 19042
Mageia 9 x86_64 as of March 29

Affected browser versions:

• Chrome Stable 89.0.4389.90 (both Windows and Linux)
• Chrome Canary 91.0.4462.0 (Windows, not tested on Linux)
• Strangely enough, I couldn't reproduce it with any Chromium version.

Issue description:
Since Chrome 89.0.4389.90 (possibly older 89.0.x builds too), there's severe audio stuttering in most Godot web exports when playing music.
This appears to be a Chrome regression as the same exports were working fine prior to a recent update.

This is likely this upstream bug report: https://bugs.chromium.org/p/chromium/issues/detail?id=1187016
Which is the consequence of security fixes in ScriptProcessorNode.

The upstream bug report is supposed to have been fixed a few days ago in Chrome Canary, but I could still reproduce it with @3p0ch-NG's reproduction project. I'll report it upstream. Edit: Done: https://bugs.chromium.org/p/chromium/issues/detail?id=1187016#c66

Edit 2: New upstream issue: https://bugs.chromium.org/p/chromium/issues/detail?id=1193494

(Moved this report from #43210 (comment) which is a different issue from what #43210 initially handled.
CC @rcbotCheeseh @CedLec @3p0ch-NG who initially commented on that other issue.)

Steps to reproduce:

• This test project can be used to reproduce the issue: https://www.newgrounds.com/portal/view/project/1594770
  There should be significant stuttering at the start and possibly throughout the whole playback (though I've also had times where it didn't stutter reliably).
• Make sure to click the game window to start the audio playback, as per browser policy.

Minimal reproduction project:
https://www.newgrounds.com/portal/view/project/1594770

[akien-mga]

Might be useful for Godot users who can reproduce this issue to test Chrome Canary to see if https://bugs.chromium.org/p/chromium/issues/detail?id=1187016 is fixed for your test cases. It doesn't seem fixed for @3p0ch-NG's in my tests, but it might be for simpler test cases.

To help upstream with debugging, it could also be useful to make a minimal reproduction project that they could run from Godot 3.2.3 or 3.3 RC 6 directly with one-click deploy, and/or provide a zipped export that they could self-host to reproduce the bug locally.

[3p0ch-NG]

I've uploaded the minimal project source here

[ljvmiranda921]

I also experience the same issue. To add, I found some leads in this reddit thread:

It seems that even if we export by Threads, the new versions of Chrome and Firefox don't allow this due to some CORS headers. It will work fine if you're running locally, but if you're running it in a server (itch.io, etc.), it will require some headers to be present.

I saw a workaround that involves updating the actual javascript file and manually adding-in the music. I haven't tried it yet but may be a good lead.