# Inconsistent black video

**URL:** <https://devforum.zoom.us/t/inconsistent-black-video/37502>\
**Category:** macOS\
**Created:** [December 2, 2020, 11:45pm UTC](https://devforum.zoom.us/t/inconsistent-black-video/37502 "2020-12-02T23:45:39Z")\
**Posts on this page:** 1\
**Showing post:** 5

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**Author:** ![timazed](https://avatars.discourse-cdn.com/v4/letter/t/c2a13f/32.png) [@timazed](https://devforum.zoom.us/u/timazed)\
**Post date:** [December 9, 2020, 5:57am UTC](https://devforum.zoom.us/t/inconsistent-black-video/37502/5 "2020-12-09T05:57:36Z")

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Hi @jon.zoom,

I’ll try to get more concrete data. But the dead locking was previously occurring in the lock/unlock methods of the video open gl layer as reported here [App hangs when using custom UI with video](https://devforum.zoom.us/t/app-hangs-when-using-custom-ui-with-video/20353/10)

The hotfix in the ticket seemed to work until a recent update that moved to a new implementation using metal. I’m not sure if there was ever actually a fix released. I have concerned that the video layer is expected to be used in a particular way and outside of that particular usage the race condition fires more often.  
e.g. Using the view to be rendered in a collectionview rather than custom views where the refresh cycle is managed differently.

Anyway I’ll do my best to capture something and share it.

One note is that I see it happen in release mode rather than debug mode.

Cheers,  
Tim

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