Hello everyone!

I'm from Brazil, and I'm experiencing a strange audio issue with the Web Browser Input in vMix 29. After several tests, I've managed to identify the specific conditions that trigger the problem.

System specifications:

- Software: vMix 29.0.0.49 x64
- Operating system: Windows 11
- Laptop: Acer Predator Helios 16 AI
- GPU: NVIDIA GeForce RTX 5070 Laptop GPU (8 GB)
- RAM: 32 GB
- Graphics adapter: NVIDIA RTX 5070 correctly detected and used by vMix

Problem description:

I initially noticed the issue while watching a live TV broadcast through Globoplay, a Brazilian streaming platform.

When playing a video with audio through the Web Browser Input, everything works normally as long as the vMix window remains visible.

However, when I open another application, such as Brave Browser or even Windows Notepad, and completely cover the vMix window, the audio becomes robotic and distorted. Voices change in pitch, and occasional crackling or popping sounds can be heard.

As soon as any part of the vMix window becomes visible again, the audio immediately returns to normal.

I also tested another HTML5 video source, with the same result. Therefore, the issue does not appear to be exclusive to Globoplay.

Important findings:

1. When vMix and Brave are displayed on separate monitors (using an HDMI-connected display), the audio remains normal.
2. When Brave or Windows Notepad covers only part of the vMix window, the audio remains normal.
3. When either application completely covers the vMix window, the audio becomes robotic and distorted.
4. When any part of the vMix window becomes visible again, the audio returns to normal.
5. Playing a local MP4 file directly in vMix works normally, even when the vMix window is completely covered.
6. The issue occurs with different video sources inside the Web Browser Input, suggesting that it is not related to a specific website.
7. This appears to be related specifically to the Web Browser Input rather than vMix's general audio processing.

Troubleshooting already performed:

- Tested Web Browser versions V103 and V115 — same issue.
- Disabled GPU acceleration in the Web Browser Input — no improvement.
- Changed the vMix application priority from Normal to AboveNormal — no improvement.
- Disabled Windows audio enhancements and spatial audio.
- Changed Windows power mode from Balanced to Best Performance — no improvement.
- Confirmed that vMix is using the dedicated NVIDIA RTX 5070 GPU.
- Tested with Brave and Windows Notepad, confirming that the issue is not exclusive to a particular application.
- Confirmed that the audio works correctly when the vMix window is partially visible or displayed on another monitor.
- Tested local MP4 playback in vMix, which works normally even when another application covers the vMix window.

Additional issue: Display Method setting reverting to Auto

During troubleshooting, I also noticed an unusual behavior with the Display Method setting.

I tried changing the Display Method from `Auto` to `Legacy` under the vMix performance settings.

However, after clicking OK, closing vMix, and reopening it, the setting always reverts to `Auto`.

I repeated this procedure several times, with the same result.

To verify whether vMix was saving settings correctly, I changed the interface theme, restarted the software, and confirmed that the new theme was successfully saved.

Therefore, the problem appears to affect the Display Method setting specifically, rather than all vMix settings.

I don't know whether this behavior is related to the Web Browser Input audio issue, but I thought it was worth reporting.

Additional technical observations:

While investigating the issue through Windows Task Manager, I noticed that the Web Browser Input uses multiple `CefSharp.BrowserSubprocess.exe` processes, along with a `CefBrowserInstance.exe` process.

The dedicated NVIDIA GPU is correctly detected, and there were no obvious signs of excessive GPU or CPU usage during the tests.

Possible cause (not confirmed):

Based on the behavior observed, I suspect the issue might be related to how Windows or Chromium Embedded Framework (CEF) handles background rendering, audio processing, or window occlusion when the main vMix window becomes completely hidden behind another application.

However, I have not confirmed the actual cause.

Questions for the vMix team and community:

1. Has anyone experienced similar robotic or distorted audio from the Web Browser Input when the vMix window is fully covered by another application?
2. Could this be related to Chromium/CEF background throttling or window occlusion detection?
3. Is there any known workaround to keep the Web Browser Input processing audio normally when the vMix window is not visible?
4. Could this be a bug in vMix 29 or its embedded browser implementation?
5. Is it expected behavior for the Display Method setting to revert from Legacy to Auto after restarting vMix?

I can provide screen recordings demonstrating the issue and the exact conditions under which it occurs, if needed.

Any assistance or suggestions would be greatly appreciated.

Thank you!

Hi Greg!

Thank you for your quick response and for clarifying the issue!

I understand that this is related to Windows power management and that running vMix behind another application is not recommended.

However, I would like to mention that I also tested Windows 11 with the power mode set to "Best Performance", while keeping my laptop connected to AC power, and the issue still occurred.

Is there any specific Windows setting or officially recommended workaround that could prevent this behavior without requiring the vMix window to remain visible at all times?

I understand this may be outside vMix's direct control, but I would appreciate any additional guidance.

Thanks again for your help!