Crackle audio noise on old or low-end iOS devices

• Component: Media
• Status: NEW ---

[Takahiro Aoyagi]

I hear crackle noise from video element (and maybe other media) on iOS 15 Safari if I get user media with echo cancellation option.


How to reproduce

1. Go to https://takahirox.github.io/ios-webaudio-test/video_user_media.html on your iOS device with Safari (and other browsers)
2. Every item is checked and press run button
3. You hear crackle noise from video audio
4. Reload the page, uncheck "echoCancellation", and press run button
5. You hear less noise

We tested on several iOS/iPad devices and found that this problem seems to happen only on old (or low-end) models.

The models on which the audio noise problem is reproducible

- iPhone 8+ (released in 2017)
- iPhoneX (released in 2017)

The models on which the audio noise problem isn't reproducible

- iPhone XS Max (released in 2018)
- iPhone11 (released in 2019)
- iPhone SE2 (released in 2020)
- iPad 5th generation (released in 2017)

I guess the noise problem sounds like being caused by lack of resources (CPU, memory, or audio buffers)?

[Takahiro Aoyagi]

Might be related: https://bugs.webkit.org/show_bug.cgi?id=227199

[Radar WebKit Bug Importer]

<rdar://problem/84113756>