Microphone and Audio Capture Configuration

Instructions for configuring microphone and tab audio capture permissions

By default, the browser will prompt the first time PixieBrix requests to use the microphone.

Manually Allowing/Blocking Microphone Capture

Navigate to Settings > Privacy & Security > Site Settings > Microphone > PixieBrix.

For the Microphone permission, select "Allow" from the dropdown.

Setting the Microphone Permission

Allowlisting PixieBrix Audio Capture via Policy

If you are an Enterprise customer with a custom extension build, provide the extension ID of your extension

To automatically allow audio capture using PixieBrix, use the following Chrome policies:

Microphone Capture

• AudioCaptureAllowedUrls

Screen/Window/Tab Audio Capture

Provide at most one of the following screen/window/tab capture policies. For example, setting the TabCaptureAllowedByOrigins policy causes the browser to not consider the ScreenCaptureAllowed policy

• ScreenCaptureAllowedByOrigins

  • Allows Desktop, Window, and Tab capture

  • Enabling Screen capture is useful for recording audio from other applications, e.g., desktop telephony applications

  • Operating System Compatability: desktop audio capture is not available on MacOS due to OS limitations

• WindowCaptureAllowedByOrigins

  • Allows Window and Tab capture

• TabCaptureAllowedByOrigins

  • Allows Tab capture only

For more information on URL patterns, see Chrome's documentation for Enterprise policy URL pattern format.

Microsoft Configuration

If you have a custom extension build, replace the entry with your extension ID

Registry Path	Type	Entries
Software\Policies\Google\Chrome\AudioCaptureAllowedUrls	List of strings	PixieBrix: [*.]mpjjildhmpddojocokjkgmlkkkfjnepo PixieBrix BETA: [*.]mpapkmgkphbggmlekkfnoilmafnbfile
Software\Policies\Google\Chrome\TabCaptureAllowedByOrigins	List of strings	PixieBrix: [*.]mpjjildhmpddojocokjkgmlkkkfjnepo PixieBrix BETA: [*.]mpapkmgkphbggmlekkfnoilmafnbfile

Example: Setting the AudioCaptureAllowedUrls policy via Windows Registry

To set the AudioCaptureAllowedUrls policy via Windows Registry, create a key for Software\Policies\Google\Chrome\AudioCaptureAllowedUrls and add a REG_SZ value for each allowlist entry (entries for list keys should be 1, 2, 3, ...):

Setting the AudioCaptureAllowedUrls policy via the Windows Registry

Configuring the default Audio Capture Policy

To configure the default allow/deny audio capture policies across all extensions/websites, use the following policies:

• AudioCaptureAllowed: microphone

• ScreenCaptureAllowed: tab audio

If set to false, only allowlisted extensions/origins will be able to capture audio. See the previous section:Microphone and Audio Capture Configuration

Registry Path	Type	Value
Software\Policies\Google\Chrome\AudioCaptureAllowed	REG_DWORD	1
Software\Policies\Google\Chrome\ScreenCaptureAllowed	REG_DWORD	1

Frequently Asked Questions

How do I determine my browser's default microphone?

To view your browser's default microphone, visit Settings > Privacy & Security > Site Settings > Microphone. The microphones available to your browser will be listed in a drop-down:

chrome://settings/content/microphone

Why does PixieBrix show the tab picker to capture system audio?

Chrome's permissions model currently only allows automatic tab media capture if the user has invoked the extension on the tab by:

• Clicking the icon in the toolbar

• Clicking a native context menu action

• Invoking a registered Chrome keyboard shortcut associated with the extension

Unfortunately, Chrome does not detect clicking an embedded extension element (e.g., the floating action button, text selection menu) as invoking the extension. Therefore, for UI/UX consistency, PixieBrix always shows the media source picker.

We're working with the browser vendors to adjust the requirements

What audio codec does PixieBrix capture/stream in?

PixieBrix uses the state-of-the-art Opus codec in WebM audio format (MIME type: audio/webm;codecs="opus" ). For more details, see Mozilla's Audio Codecs Guide

Can PixieBrix capture audio from desktop applications?

ScreenCapture must be allowed.

Due to operating system restrictions, system audio capture is only available on Windows.

To capture system audio, select "Entire Screen" and toggle on "Also share system audio".