Open Radar

 
28-Aug-2013 11:25 PM Erik Price:
Summary:
Adding a periodic time observer to an AVPlayer playing an HLS asset using a serial dispatch queue results in a crash in -[AVPlayerPeriodicCaller _effectiveRateChange] .

Steps to Reproduce:
1. Create an AVPlayer for a HLS URL and add its AVPlayerLayer to the view hierarchy.
2. Call -play on the AVPlayer.
3. Create a dispatch_queue_t using dispatch_queue_create("myQueue", DISPATCH_QUEUE_SERIAL).
4. Add a periodic time observer to the AVPlayer on the created dispatch queue using an interval of CMTimeMake(120.0f, 600) and an empty block (or just put a call to NSLog in the block).

Expected Results:
I expected the periodic time observer to execute the block with no problems.

Actual Results:
Nearly every time I can get this to EXC_BAD_ACCESS in -[AVPlayerPeriodicCaller _effectiveRateChange]. If I can't, then I just have to add another periodic observer or two and it will crash reliably.

Regression:

Notes:
I'm attaching a zipped Xcode project that demonstrates the bug. Run the app in the iOS simulator and then click the "BOOM" button to add the periodic time observer(s).

28-Aug-2013 11:25 PM Erik Price:
'AVPlayerPeriodicCallerCrash.zip' was successfully uploaded

29-Aug-2013 11:17 AM Erik Price:
I do not experience the crash if I insert a call to -pause immediately before adding the periodic observer and then insert a call to -play immediately afterward. This is a sufficient workaround for my needs, but it should be documented that periodic observers should not be added to an already-playing AVPlayer when using private serial dispatch queues.