Make sure to read my article on AVAssetWriter crashing when using CMAF compliant segments before exploring this sample project.

Minimal sample to demonstrate writing out CMAF compliant segments from a real source fails with an error on Intel macs on Ventura.

The error is in the AVFoundationErrorDomain with code -11800, containing an underlying error in the NSOSStatusErrorDomain with code -16364.

• The AVAssetWriter must be configured with outputFileTypeProfile set to .mpeg4CMAFCompliant.
• The AVAssetWriterInput added to the writer must have expectsMediaDataInRealTime set to true.
• Samples must be appended to the input either:
  • At an variable rate, for example because no new sample is generated when there is no change at the souce (like ScreenCaptureKit does).
  • Frames are delivered significantly faster than 60 FPS.
• The application must run on an Intel mac, Apple Silicon macs are not affected.

This repository contains a sample app demonstrating the issue:

• Open realtime-cmaf-crash-sample.xcodeproj in Xcode 14.2 or newer on an Intel mac
• Build & run the app
• Hit the "Start" button

After about 5 segments are delivered to the delegate the app will crash.

• On the AVAssetWriter change outputFileTypeProfile to mpeg4AppleHLS.
  • Note that this will either produce a different format output.
• On the AVAssetWriterInput set expectsMediaDataInRealTime to false.
  • Might have unexpected side effects dropping frames because isReadyForMoreMediaData might become inaccurate.

Nonstrict B.V., Mathijs Kadijk & Tom Lokhorst, released under MIT License.