Here is the attachment of logs: teams.txt
Video Resolution Drops in ACS App When Teams UI is Resized
Problem Summary
Our application, built using Azure Communication Services (ACS), joins Microsoft Teams meetings and sends high-resolution video (3840x2160 @ 30fps). However, we are experiencing a consistent issue where the video resolution sent from our ACS app drops significantly when a Teams user resizes their Teams window or changes the layout.
Detailed Description
The ACS app captures video at 4K resolution.
When a Teams participant resizes their window or switches layout (e.g., gallery view), the resolution of the video stream sent from the ACS app drops to 960x540 or lower.
This occurs despite sufficient bandwidth and system resources.
The issue appears to be triggered by Teams dynamically adjusting the requested video resolution based on UI layout.
What We’ve Tried
Verified that the ACS app continues to capture high-resolution video.
Monitored bitrate and resolution changes using logs (attached).
Observed that Teams appears to downscale the stream based on layout changes.
Questions
Is there a way to prevent Teams from downscaling the ACS video stream based on UI layout?
Can we enforce a minimum resolution for ACS video streams in Teams meetings?
Would spotlighting or pinning the ACS participant help maintain higher resolution? Can this be done programmatically?
Are there any configuration options or roadmap features to address this?
Impact
This issue affects the quality of our video experience and is critical for our application's use case, which requires consistent high-resolution video delivery.
Azure Communication Services
2 answers
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Shree Hima Bindu Maganti 4,615 Reputation points Microsoft External Staff Moderator
2025-06-02T14:56:53.9+00:00 Hi @dev
The issue with video resolution dropping in your ACS app when the Teams UI is resized is likely due to Microsoft Teams dynamically adjusting video quality based on available resources and UI layout changes. When a Teams participant resizes their window or changes the layout, Teams may request a lower resolution for the video stream to optimize performance, even if your ACS app is capturing high-resolution video.Unfortunately, there is no direct way to prevent Teams from downscaling the ACS video stream based on UI layout changes. The browser and Teams application manage video quality and resolution adjustments automatically, influenced by factors such as CPU load and network conditions.
To maintain a higher resolution, spotlighting or pinning the ACS participant may help, as it can prioritize the video stream from your application. However, whether this can be done programmatically depends on the specific APIs and capabilities provided by Microsoft Teams.
Currently, there are no specific configuration options mentioned to enforce a minimum resolution for ACS video streams in Teams meetings.
References:
- Overview of video issues
- Best practices for subscribing to video feeds
Let me know if you have any further assistances needed.