Sequence of frames causes VTDecompressionSession to hang on iPhone XS

Originator:matt
Number:rdar://45593345 Date Originated:2018-10-26
Status:Open Resolved:
Product: Product Version:
Classification: Reproducible:every time
 
Area:
VideoToolbox

Summary:
The decompression session will freeze irrecoverably while playing a video that includes a certain sequence dropped frames. 

Steps to Reproduce:
Play the attached video on an iPhone XS in Safari
(here's a link to my site http://mattdonahoe.com/dropbox/decoder-freeze.mp4 )

Expected Results: 
Video is playable, and after playback you can scrub back to the beginning and replay.

Actual Results:
It will reach the middle and freeze. You will not be able to play it again. The session will go black.

Version/Build:
12.0.1

Configuration:
iPhone XS (and XS Max)


Note that I found this why investigating a freeze bug in my video streaming app. When this happens in my app, I am forced to kill the app. Upon rebooting, the very first VTDecompressionSession I create will hang for 10 seconds before failing, and then things will work again. It surprises me that problems persist between app launches!

Comments


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