Safari 16 cannot play WebM Opus from blob URL (breaks Construct 3)

• Component: Media
• Status: RESOLVED FIXED

[Ashley Gullen]

Safari 16 on macOS appears to have support for playback of WebM Opus in the HTML <audio> element. However it does not work if passed a blob: URL.

Minimal repro: https://downloads.scirra.com/labs/bugs/webmblob/

Click "Play normally" and it will play from a normal filename. Click "Play from blob URL" and it will play from fetching the same file as a blob, calling URL.createObjectURL(blob), and playing that URL.

Observed result: clicking "Play from blob URL" does not play any audio. It also logs an error event in the console.

Expected result: it should still support playing from a blob URL. It works in Chrome, and it also works in Safari 16 if playing an MP4 (AAC) audio file. It appears only WebM Opus playback is broken when using a blob URL.

Our commercial web app Construct (www.construct.net) relies on playing audio from blob URLs in several places (especially when the user previews their project). Based on feature-detection for WebM Opus it has switched over to using built-in playback in Safari 16, but playback is now broken. Please fix it ASAP.

[Ahmad Saleem]

I am able to reproduce this issue in Safari 16 and Safari Technical Preview 153 does not play audio from blob URL based on Comment 0 test case.

Although, I know there are fixes in Webkit ToT recently, will this be fixed? Appreciate if someone can look into it. Thanks!

[Alexey Proskuryakov]

The behavior on this test case appears to be identical on Safari 15.6.1, so this isn't a Safari 16 regression AFAICT.

[Radar WebKit Bug Importer]

<rdar://problem/100205028>

[Ashley Gullen]

It's not really clear to me at the moment to what extent Safari is supposed to support WebM Opus - for example support appears to be inconsistent between macOS and iOS (see issue 238546). Perhaps there are other device specific requirements? I haven't seen any documentation covering this so it's hard to know if or where WebM Opus playback is meant to work in the first place.

We have a WebAssembly WebM Opus decoder as backup if canPlayType("audio/webm;codecs=opus") returns an empty string, so the result of calling that will affect whether our code switches over to built-in support and gets affected by this bug. Perhaps this regressed in an earlier release and I didn't notice yet.

Same or similar bug: fails with caf opus files, but only on iOS. It works fine on macOS. This bit me hard.

The same file plays fine via URL.

[Ashley Gullen]

This still reproduces for me in Safari 17.

[Ashley Gullen]

This still reproduces in Safari 17.4 which is meant to now have full support for WebM, but this issue still blocks us using WebM in Safari.

[Jean-Yves Avenard [:jya]]

Pull request: https://github.com/WebKit/WebKit/pull/25820

[Jean-Yves Avenard [:jya]]

Pull request: https://github.com/WebKit/WebKit/pull/25883

[EWS]

Committed 276136@main (a7b863a49945): <https://commits.webkit.org/276136@main>

Reviewed commits have been landed. Closing PR #25820 and removing active labels.

[Jean-Yves Avenard [:jya]]

*** Bug 270772 has been marked as a duplicate of this bug. ***

[Jean-Yves Avenard [:jya]]

*** Bug 272502 has been marked as a duplicate of this bug. ***