Bug 219588 – WebRTC using H.264 on M1 Macs with a built-in camera crashes

• Component: WebRTC
• Status: RESOLVED INVALID

[Kevin Griffin]

Created attachment 415536 [details]
Safari WebRTC h.264 crash

WebRTC in Safari and Safari Technology Preview on M1 MacBooks crashes when the codec used is H.264.

Reproduction example:

https://codepen.io/brainshave/pen/qBBWEpM

This codepen allows you to select which codecs will be used to mirror you camera back you. On M1 Macs with a built-in camera,
selecting H.264 and running the example will crash the page. You can uncheck "H.264" and run the example to see that VP8 and VP9 do not exhibit this behavior. This is 100% reproducable for me on a MacBook Air with an M1 chip. This happens in both Safari 14.0.1 (16610.2.11.51.8) and Release 116 (Safari 14.1, WebKit 16611.1.5.3) of Safari Technology Preview.

This crash doesn't occur in Chrome's Apple silicon build, even with H.264 selected.

A crash report from Safari is attached.

[Radar WebKit Bug Importer]

<rdar://problem/72041616>

[youenn fablet]

Thanks for the report Kevin.
Is the crash specific to the built-in camera? Can you try using the mock devices or USB cameras?

[Szymon Witamborski]

Hi Youenn,

We did some extra testing and could confirm that it's *not* reproducible on:

- M1 Air with mock devices
- M1 Mini with external camera

Hence our guess it might be related to the built-in camera in the M1 Air when encoding WebRTC streams with H264.

[youenn fablet]

Thanks Szymon, this is helpful

[Kevin Griffin]

I updated my M1 MacBook Air to macOS 11.2 today, and I no longer see Safari crashing with the codepen that Szymon provided.

[Alexey Proskuryakov]

Thank you for following up! Yes, this is fixed in macOS 11.2. I'm marking the bug as INVALID as it was a system issue below WebKit.