Bug 287809 – AudioContext.decodeAudioData throws "EncodingError: Decoding failed" when running iOS app on Apple Silicon Mac

• Status: NEW
• Component: Web Audio

In a IOS app (which is actually a web app running inside iOS WKWebView), the call to "new AudioContext.decodeAudioData()" works OK when app is running on iOS device / simulator, but fails when the app is running on Apple Silicon Mac. The error "EncodingError: Decoding failed" is thrown when trying to decode audio.

What may differ relating to Web Audio API, etc. in iOS-app-on-Mac environment comparing to iOS-app-on-iOS-device? WKWebView's user agent when running iOS app on Mac is:

"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko)"

[Alexey Proskuryakov]

Thank you for the report! This reproduces in a test app with a slightly modified version of LayoutTests/webaudio/decode-audio-data-basic.html (so that it loads over http).

Interestingly, there is no problem with UIWebView, but WKWebView fails.

[Radar WebKit Bug Importer]

<rdar://problem/145493943>

[Faks]

Hello,
Same problem here on Apple M1 Max - Mac OS Sonoma 14.6.1

We have a webapp running in iOS WKWebView.
This webapp just loads MP3 files via javascript and use decodeAudioData() to get an AudioBuffer from an ArrayBuffer after Fetch/XHR.
Works fine in every web browser (including latest Safari et Safari tech preview). No problem running in a webview on iOS and iPadOS.

PROBLEM -> running into a webview on Mac Silicon (Xcode target > My Mac > Designed for iPad)
UserAgent : "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/15E148"

The problem doesn't occurs with WAV file, only MP3.
I tried 20 different MP3 files with different byterate, frequency, etc...  Same result, decodeAudioData always fails.

Any help, tips or advises would be much appreciated, our app is already public.
Thanks for your time.