Inconsistent black video

Description
Sometimes when joining calls the screen has black video. It seems to be happen more often lately. But nothing is jumping out as obvious that is causing the issue.

Which version?
5.2.1 (42037.1112)

To Reproduce(If applicable)
Not sure how to reproduce it happens intermittently

Screenshots
Our app: https://i.imgur.com/llzOwn8.png
Default Zoom App: https://i.imgur.com/Ol1H5eb.png

1 Like

Hi @timazed, thanks for the post.

In your post, you mention that this behavior occurs when joining a meeting. However, in your screenshots, the video settings UI is being displayed. Is this only happening in the settings, or is it happening with the settings open while joining a meeting?

Additionally, can you provide some information on how frequently you are observing this behavior?

Thanks!

Hi @jon.lieblich,

It happens both in joining a call and when popping a setting. Our customers are reporting it for big surr 100% of time. I think the same bug was affecting the Zoom official app. I’m seeing reports on twitter saying it was hot fixed with an update it would be great for that to be pushed to the SDK.

Additionally I personally see black video streams show up on Catalina around 30-50% of time. I think there is some weird threading issue happening. I’ve also seen deadlocking happening more recently since the latest sdk release. Sorry for all the issues but the last two releases seem like regressions.

Cheers,
Tim

Hi @timazed, thanks for the additional info.

If this is something that was recently fixed in the Zoom app, typically we will release a fix for the SDK with the next version. If I hear any additional information regarding the fix for this, I will be sure to let you know.

I’ve also seen deadlocking happening more recently since the latest sdk release

Can you clarify where in the SDK you’ve noticed deadlock? Please provide code snippets, if applicable.

Thanks!

Hi @jon.lieblich,

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

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

Hi @timazed, thanks for the additional information.

Can you also please provide the version of Xcode used with your application as well as the logs from a session where this error occurs? Preferably, the logs from sessions on both Big Sur and Catalina. :slightly_smiling_face:

Thanks!

Hi Jon,

The issue that I originally opened was to do with big sur. But I’m seeing the occasional black video stream on catalina. I’ve been building with xcode 10 as recommended in the release notes of the SDK. I’ll do my best to capture logs but its very inconsistent.

Cheers,
Tim

Hi @timazed, thanks for the info.

This wouldn’t explain the behavior being present on Catalina, but I just wanted to make sure that you are aware that if the devices on Big Sur have the new M1 chip, they would not be compatible with the SDK yet.

That being said, we have not seen this issue on Catalina at all. Your logs from a session where this is happening will be an invaluable resource in looking into why this behavior is happening sometimes.

Thanks!

Hi @jon.lieblich,

I’ve been able to reproduce the bug in my app pretty consistently. It seems to occur after starting and ending multiple zoom meetings. Here are the zoom logs Crash-Logs.zip - Google Drive that might help your developers track down the issue.

Essentially once it gets into the state where the video is black it won’t render until the video stream is stopped and restarted for that particular user. You just see the name of the user label and a pure black screen. I will try to reproduce it in the demo app.

Cheers,
Tim

Hey @timazed,

Jon is currently out, so I will be taking over this thread until he returns.

Unfortunately, we cannot view the logs you have posted here. Can you, instead, email them to developersupport@zoom.us and include your reproduction steps so that the team can investigate further? Please include a link to this post and/or mention my name.

Also, a developer using the Windows SDK experienced a similar issue, and upgrading to the latest version of the SDK resolved it for him. It might be worth trying in your case. Please note, the latest version is available on Zoom Marketplace and not github.

Thanks!
Michael

Hi @Michael_Condon,

Sorry I must of broken the link. I will upload them again and send a link. Unfortunately I can’t use the latest SDK I’m one behind because chat is broken in the latest SDK which I reported in another ticket.

Cheers,
Tim

Hi @timazed,

In the logs you are going to send over, can you please confirm that your machine is not running the M1 chip?

Thanks!