Bug 286473 – MediaStreamTrack configuration change event is not triggered

• Component: WebRTC
• Status: RESOLVED FIXED

[Stefan Benicke]

The background blur API [1] is available in Safari. It tells correctly if backgroundBlur is enabled or not at the beginning of the MediaStreamTrack's lifetime.

The backgroundBlur setting is never updated, even if the system camera effect "Portrait" is changed.

Furthermore, the "onconfigurationchange" event [2] is never triggered, even if the system camera effect "Portrait" is changed.

The official demo [3] proves that it's working at the beginning, but doesn't trigger the configurationchange event.

I  could test on Safari Version 18.2 (20620.1.16.11.8) and also Safari Tech Preview Release 211 (Safari 18.2, WebKit 20621.1.9.111.1) on a MacBook Pro with Apple M2 Pro on macOS 15.2 (24C101). And also tested on an iPhone 13 mini with iOS 18.2.1.

[1] https://github.com/riju/backgroundBlur/blob/main/explainer.md#background-blur-api
[2] https://w3c.github.io/mediacapture-extensions/#exposing-change-of-mediastreamtrack-configuration
[3] https://googlechrome.github.io/samples/image-capture/background-blur.html

[Radar WebKit Bug Importer]

<rdar://problem/143568586>

[youenn fablet]

Pull request: https://github.com/WebKit/WebKit/pull/39584

[EWS]

Committed 289492@main (09a258d7bf2d): <https://commits.webkit.org/289492@main>

Reviewed commits have been landed. Closing PR #39584 and removing active labels.

[Stefan Benicke]

Thanks for the update!

I've tested in Safari Tech Preview 213 (https://developer.apple.com/documentation/safari-technology-preview-release-notes/stp-release-213), and the "configurationchange" event is triggered. Awesome.

Unfortunately, it still shows the wrong value of "backgroundBlur". It always shows the value that was set at the beginning of the VideoTrack's lifetime. If it was true, it will always be true, even if "Portrait" effect is turned off.

[Stefan Benicke]

I've created a new ticket for this issue https://bugs.webkit.org/show_bug.cgi?id=287692