[BUG] Error 3 (cancelled) on attempt to export video from iPhone 16

[mrt595]

Is there an existing issue for this?

• I have searched the issues (both open and closed)

Current Behavior

Uploading a video that was shot on an iPhone 16 fails with "Upload failed - The operation couldn't be completed. (SessionExporter.NextLevelSessionExporterError error 3.)

This seems to be an issue with an audio codec. (NextLevel/NextLevelSessionExporter#49)

It only happens in the app. Using Safari on iPhone works just fine.

Expected Behavior

The video should load and be processed by the server.

Steps To Reproduce

1. Create a post
2. Attach video that was shot with iPhone 16

Environment

- Device: iPhone 16 Pro
- OS:iOS 18.2
- Version:2024.12
- Build:22c152

Anything else?

I have only tried this on mstdn.social.