Bug 247614

Summary:	Only require a "transient" user activation for Web Audio rendering
Product:	WebKit	Reporter:	David Spura <david.spura>
Component:	Web Audio	Assignee:	Chris Dumez <cdumez>
Status:	RESOLVED FIXED
Severity:	Major	CC:	cdumez, eric.carlson, jer.noble, karlcow, webkit-bug-importer
Priority:	P2	Keywords:	BrowserCompat, InRadar
Version:	Safari 16
Hardware:	Mac (Apple Silicon)
OS:	macOS 13
See Also:	https://bugs.webkit.org/show_bug.cgi?id=248061

Description David Spura 2022-11-08 06:09:44 PST

After registering processor to AudioWorklet, its process method does not get called.

Please try here: https://1006044.playcode.io/

Source of the sample: https://playcode.io/1006044

Mentioned sample works in firefox, chrome and edge.

Comment 1 Radar WebKit Bug Importer 2022-11-15 06:10:16 PST

<rdar://problem/102364692>

Comment 2 Chris Dumez 2022-11-15 13:26:43 PST

Safari has stricter use gesture requirements than other browsers. We don't allow starting rendering without a user gesture. I see the demo asks the user to click a button to start rendering but my bet is that it actually starts the rendering asynchronously after getting the click.

Comment 3 Chris Dumez 2022-11-15 13:29:29 PST

Yes, I mean the click handler calls an async function which does a:
```
await e.audioWorklet.addModule(n),
```

Before it connects the node to the graph. By that time, the user gesture is lost in Safari. I wish we could relax the user gesture requirement a bit (e.g. only require a "recent" gesture) but I usually get push back from our media team when I suggest that.

Comment 4 Chris Dumez 2022-11-15 14:16:08 PST

Pull request: https://github.com/WebKit/WebKit/pull/6529

Comment 5 EWS 2022-11-15 22:29:15 PST

Committed 256721@main (7cc4b4216132): <https://commits.webkit.org/256721@main>

Reviewed commits have been landed. Closing PR #6529 and removing active labels.