[Critical Bug] ScreenCapture shows content in Discord

J. Diego Rodríguez Royo 6

I have been trying this UWP sample and it work cool, but it has a critical bug with Discord (and maybe other streaming/video screen share apps).
I built the example and I opened it, then I shared my screen on discord. If it's the whole screen, it works by hiding all the app content with

IsScreenCaptureEnabled = false

But not so cool with

AppCapture.SetAllowedAsync(true)

(It shows all the app content, Windows doesn't even detect that it is being captured by Discord!)

But the more critical bug if I use IsScreenCaptureEnabled = false, I put the video on the app, and in Discord I select to transmit that specific app only that it is trying to block the capture, it will show the video on Discord (and only the video, it's like it focuses on the video, but that happens too without screen capture blocking).

This issue happens at UWP but it could happen too at WindowsApp SDK (I couldn't find a way to disable screen captures in WindowsApp SDK to try to reproduce the issue)

Roy Li - MSFT 31,786 Reputation points Microsoft Vendor

2022-11-07T08:44:17.863+00:00

Could you please be more specific about I put the video on the app? Does it mean playing videos in the UWP app? The Discord could capture the Video but no other parts of the app when set IsScreenCaptureEnabled to false. Is that right?
J. Diego Rodríguez Royo 6 Reputation points

2022-11-07T23:09:37.797+00:00

Bad Spanish-English translate sorry
I put the video on the app = I play a video on the app
Yes, that's it, Discord only captures the video when the video is played (always), which causes that when IsScreenCaptureEnabled to false, the video is captured too.
Roy Li - MSFT 31,786 Reputation points Microsoft Vendor

2022-11-10T06:18:55.597+00:00

@J. Diego Rodríguez Royo I've asked the team about this. There might be some time delay.
Roy Li - MSFT 31,786 Reputation points Microsoft Vendor

2022-11-18T06:47:17.427+00:00

@J. Diego Rodríguez Royo After talking with the team, we've found something. We tested the Disabling screen capture sample on our side.

1) For the AppCapture.SetAllowedAsync() method, after setting this to false, Discord and the snipping tool could still capture the content. But when using GameBar capture function, the content will be blocked. This behavior is expected. The description here - DisablingScreenCapture sample mentions that Allowing and blocking system-initiated app capture such as Xbox Game Bar. Discord and the snipping tool are not doing a system-level recording so the AppCapture.SetAllowedAsync() is not working in their scenario. Or in other words, the AppCapture.SetAllowedAsync() is not designed for scenario, it is user for apps like Xbox Game Bar.

2) For the IsScreenCaptureEnabled property. It works correctly when we test using Discord and the snipping tool. The content will be blocked no matter if it is playing the video. This result is different from the result you get. Could you please make a sample that could reproduce your issue in a blank app and share it with us?
Roy Li - MSFT 31,786 Reputation points Microsoft Vendor

2022-11-23T01:12:35.017+00:00

@J. Diego Rodríguez Royo Hope you've been well. Have you checked my comment? It will be appreciated if you could share a simple sample (not the official sample) with us.
J. Diego Rodríguez Royo 6 Reputation points

2022-11-26T11:32:35.88+00:00
@Roy Li - MSFT sorry for being late, I was busy so I couldn't do some testing to get this problem again and again so I could give you detailed steps, but here they are:

(You can jump over the first point, is just to show that it works right on under some conditions)

So first I do, with the sample app (because I didn't write an app with this api yet) is open it, then staying on "1) Enabling screen capture" page, share the app window exclusively on discord and navigate to the second page "2) Disabling screen capture". Here the API works correctly and blocks the content.

But if you start sharing the app window exclusively (recommended to stop sharing a share again if you were already sharing) when you are already at the "2) Disabling screen capture" page (so IsScreenCapturedEnabled is set to true before sharing the app on discord) it will block the content too, but then if you play the video, only the video will be shared on discord at a low framerate.
Roy Li - MSFT 31,786 Reputation points Microsoft Vendor

2022-11-28T03:14:12.27+00:00

@J. Diego Rodríguez Royo Thank you for the information. I'll talk with the team about this.
Roy Li - MSFT 31,786 Reputation points Microsoft Vendor

2022-11-29T02:56:52.003+00:00

@J. Diego Rodríguez Royo We could reproduce this behavior on our side. What we could see is that only the video is shared but not the rest of the app content. It looks to be related to something the Discord is doing. It is getting the video stream from the app directly not by capturing the app content. Please try to open an issue on the WinUI Github here: WinUI-Issues.
J. Diego Rodríguez Royo 6 Reputation points

2022-11-29T16:57:35.77+00:00

Done! https://github.com/microsoft/microsoft-ui-xaml/issues/7976