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Edge on Ubuntu: V4L2 buffer corruption when using blur/virtual background in Teams PWA — regression in Edge 146

lakes 0 Reputation points
2026-03-19T18:15:32.32+00:00

Had Claude summarize all of the troubleshooting we did. Apologies if AI spew triggers you:

Platform:

  • OS: Ubuntu 24.04 LTS
  • Edge version: 146.0.3856.62-1 (regression from 145.0.3800.82-1)
  • GPU: Intel Iris Xe (TGL GT2), Mesa 25.2.8
  • Display server: Wayland

Description:

Camera video is corrupted in Microsoft Teams PWA when blur or virtual background is enabled. The issue affects two different cameras simultaneously — a Logitech C920 (external USB) and an integrated Dell webcam — ruling out a hardware fault. Disabling blur/virtual background restores normal camera function. The issue is not reproducible in Edge 145.

Steps to reproduce:

  1. Open Microsoft Teams PWA in Edge 146
  2. Join a meeting or open camera preview in settings
  3. Enable background blur or a virtual background
  4. Observe corrupted video output

Expected behaviour: Clean video output with blur/virtual background applied, as worked correctly in Edge 145.

Actual behaviour: Corrupted video frames delivered from the V4L2 capture pipeline.

Error log from Edge:

ERROR:media/capture/video/linux/v4l2_capture_delegate.cc:1136] Dequeued v4l2 buffer contains corrupted data (385344 bytes).
ERROR:base/memory/shared_memory_switch.cc:289] Failed global descriptor lookup: 7

Additional notes:

  • V4L2 formats available on both cameras: MJPG and YUYV 4:2:2
  • Corruption appears linked to Edge 146's changed shared memory handling for video capture buffers when background processing is active
  • Downgrading to Edge 145 resolves the issue but renders the profile incompatible on re-upgradePlatform:
    • OS: Ubuntu 24.04 LTS
      • Edge version: 146.0.3856.62-1 (regression from 145.0.3800.82-1)
        • GPU: Intel Iris Xe (TGL GT2), Mesa 25.2.8
          • Display server: Wayland
    Description: Camera video is corrupted in Microsoft Teams PWA when blur or virtual background is enabled. The issue affects two different cameras simultaneously — a Logitech C920 (external USB) and an integrated Dell webcam — ruling out a hardware fault. Disabling blur/virtual background restores normal camera function. The issue is not reproducible in Edge 145. Steps to reproduce:
    1. Open Microsoft Teams PWA in Edge 146
      1. Join a meeting or open camera preview in settings
        1. Enable background blur or a virtual background
          1. Observe corrupted video output
    Expected behaviour: Clean video output with blur/virtual background applied, as worked correctly in Edge 145. Actual behaviour: Corrupted video frames delivered from the V4L2 capture pipeline. Error log from Edge: 
      ERROR:media/capture/video/linux/v4l2_capture_delegate.cc:1136] Dequeued v4l2 buffer contains corrupted data (385344 bytes).

ERROR:base/memory/shared_memory_switch.cc:289] Failed global descriptor lookup: 7

  
  **Additional notes:**
  
  - V4L2 formats available on both cameras: MJPG and YUYV 4:2:2
  
  - Corruption appears linked  to Edge 146's changed shared memory handling for video capture buffers  when background processing is active
  
  - Downgrading to Edge 145 resolves the issue but renders the profile incompatible on re-upgrade
Microsoft Teams | Microsoft Teams for business | Meetings and calls | Audio and video
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  1. Ian-Ng 11,235 Reputation points Microsoft External Staff Moderator
    2026-03-19T20:15:45.8766667+00:00

    Hi @lakes, 

    Thank you for detailed information you posted. 

    The detailed summary related to the video corruption issue you're encountering in the Microsoft Teams PWA is very much appreciated. Having access to the specific error logs and the version comparison between Edge 145 and 146 allows for a much deeper look into the root cause. 

    The information you shared suggests a regression in the browser's Inter-Process Communication (IPC) layer, specifically regarding how shared memory is brokered between the V4L2 capture pipeline and the background processing service. The failed global descriptor lookup error typically indicates that when background blur or virtual backgrounds are enabled, the browser is unable to correctly map the video buffer into the secure sandbox. This results in the corrupted data logs because the background segmentation process is receiving incomplete or incorrectly addressed memory segments. 

    Because this is reproducible across multiple hardware devices but resolved by downgrading, it show that a software-side regression within the version 146 update. In the meantime, you can find relief by launching Edge via the terminal using specific flags to bypass certain shared memory or hardware acceleration paths: 

    • microsoft-edge --disable-features=WebRtcRemoteVideoDecoderSharedMemory 
    • microsoft-edge --ozone-platform=x11 (This tests if the issue is specific to the Wayland buffer implementation) 

    It is also helpful to use the built-in feedback tool (Alt+Shift+I) to submit these findings. Including the snippet from v4l2_capture_delegate.cc will be important for the engineering team to identify the exact change in the Chromium codebase that triggered this behavior. 

    Please let me know if any of those flags restore your camera functionality during your meetings. 

    I appreciate your contribution and understanding. 

    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

  2. Q&A Assist
    2026-03-19T18:16:01.6766667+00:00
    AI generated content. This question contains an answer created with AI from Q&A Assist. Learn more

    This behavior matches a regression scenario in the Teams/Edge Linux stack where camera processing (blur/virtual background) breaks video capture, similar to other known Linux camera issues in Teams.

    From the available information, there is no documented Linux-side configuration or V4L2 tuning that resolves this; the only confirmed pattern in context is that when Teams/Edge has a camera pipeline bug on Linux, the workaround is to avoid the affected feature or update once Microsoft ships a fix. For example, for upside‑down cameras in Teams on iPad, the resolution was delivered entirely by a service-side/client update and required only restarting the app after the fix was deployed.

    Given that:

    1. The issue is a regression between Edge 145 and 146.
    2. It only occurs when background effects are enabled in Teams PWA.
    3. It affects multiple cameras and is tied to Edge’s capture/processing path.

    The practical options based on current documented patterns are:

    1. Avoid the affected feature until a fix is released
      • Use Teams PWA in Edge 146 with background effects disabled (no blur/virtual background).
      • This aligns with the Linux known-issues guidance for Teams, where unsupported or problematic features (for example, Viva Connections on Linux) must be avoided until explicitly supported or fixed.
    2. Use an alternative client path that does not hit the regression
      • Use the Teams web experience in a different browser that does not exhibit the V4L2 corruption when background effects are enabled.
      • This is analogous to the guidance where certain Teams features are not supported or are broken on Linux desktop and require using a different client or path.
    3. Monitor for a product-side fix and restart after it is deployed
      • When Microsoft addresses similar camera/video issues, the fix is typically shipped via client/service update and requires only restarting the app to pick up the change, as with the upside‑down camera issue in Teams.
      • After Edge/Teams updates, fully quit Edge (including background processes) and relaunch, then re‑test blur/virtual background.
    4. Avoid downgrading profiles across Edge versions
      • Downgrading to Edge 145 is known to work around the issue but causes profile incompatibility on re‑upgrade. To avoid profile corruption or data loss, keep Edge on the supported/latest channel and use the workarounds above instead of repeatedly downgrading.

    There is no supported V4L2- or OS-level tweak documented in the provided material that corrects this corruption when background processing is active; resolution depends on a fix in Edge/Teams.

    References:

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