rafaelcanovas/mic-check

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mic-check

A lightweight package for requesting camera and microphone permissions from the browser with better error handling.

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Note: This library does not include any UI or components and is designed to help you implement those pieces more easily through better error handling. You can, however, use the code included in the examples.

Motivation

One of the most frustrating pieces of building a video chatting website is helping the user set up camera and microphone access. Ideally, you should be able to use the Permissions API to request media device access, but it isn't yet available on Safari which accounts for a significant group of users.

navigation.mediaDevices.getUserMedia() is now available on all major browsers, but it returns different errors for the same problems across various browsers (Chrome, Firefox, Edge, Safari) and operating systems (macOS, Windows). Some problems, like the system denying permission, are more common on macOS. Whereas being unable to start the video stream due to another application using it is more Windows specific. Oh, and Firefox is the only one with any error documentation at all.

Handling these errors across browsers and OS's can be difficult, but is crucial to a great user experience. mic-check categorizes the major errors and allows you to focus on building a great experience!

Installation

npm install mic-check

or

yarn add mic-check

Usage

import {
  MediaPermissionsError
  MediaPermissionsErrorType,
  requestMediaPermissions
} from 'mic-check';

requestMediaPermissions()
	.then(() => {
		// can successfully access camera and microphone streams
		// DO SOMETHING HERE
	})
	.catch((err: MediaPermissionsError) => {
		const { type, name, message } = err;
		if (type === MediaPermissionsErrorType.SystemPermissionDenied) {
			// browser does not have permission to access camera or microphone
		} else if (type === MediaPermissionsErrorType.UserPermissionDenied) {
			// user didn't allow app to access camera or microphone
		} else if (type === MediaPermissionsErrorType.CouldNotStartVideoSource) {
			// camera is in use by another application (Zoom, Skype) or browser tab (Google Meet, Messenger Video)
			// (mostly Windows specific problem)
		} else {
			// not all error types are handled by this library
		}
	});

Seperate audio/video permission

import {
  MediaPermissionsError
  MediaPermissionsErrorType,
  requestAudioPermissions,
  requestVideoPermissions,
  requestMediaPermissions
} from 'mic-check';

// Requesting AUDIO permission only:
requestAudioPermissions()
	.then(() => {})
	.catch((err: MediaPermissionsError) => {});

// another way to request AUDIO only...
requestMediaPermissions({audio: true, video: false})
	.then(() => {})
	.catch((err: MediaPermissionsError) => {});

// Requesting VIDEO permission only:
requestVideoPermissions()
	.then(() => {})
	.catch((err: MediaPermissionsError) => {});

// another way to request VIDEO only...
requestMediaPermissions({audio: false, video: true})
	.then(() => {})
	.catch((err: MediaPermissionsError) => {});

Documentation

requestMediaPermissions() Errors

Error Type (MediaPermissionsError)	Description
SystemPermissionDenied	Browser does not have access to camera or microphone (common on macOS)
UserPermissionDenied	User did not grant camera or microphone permissions in the popup
CouldNotStartVideoSource	Another application or browser tab is using the camera (common on Windows)
Generic	Everything else

Browser Errors

These are common errors and recommended user actions to resolve them that we have discovered from testing the four major browsers on Windows and macOS.

Problem	OS (macOS, Windows)	Chrome	Safari	Edge	Firefox	Error Type (MediaPermissionsError)	Recommended User Action
Browser doesn't have System Preferences access to camera or mic	macOS	NotAllowedError: Permission denied by system	N/A (Safari always has access)	NotAllowedError: Permission denied	NotFoundError: The object can not be found here.	SystemPermissionDenied	Open Mac System Preferences and enable under Camera
Browser doesn't have System Preferences access to camera or mic	Windows	NotReadableError: Could not start video source	N/A (Safari not available)	NotReadableError: Could not start video source	NotReadableError: Failed to allocate videosource	N/A	Open Windows Settings and enable under Camera
User denied permission to access camera or mic	macOS, Windows	NotAllowedError: Permission denied	NotAllowedError: The request is not allowed by the user agent or the platform in the current context, possibly because the user denied permission.	NotAllowedError: Permission denied	NotAllowedError: The request is not allowed by the user agent or the platform in the current context.	UserPermissionDenied	Manually give permission by clicking on Camera Blocked icon (Safari needs a reprompt)
Camera in use by another application (Zoom, Webex) or tab (Google Meet, Messenger Video)	Windows	NotReadableError: Could not start video source	N/A (Safari not available)	NotReadableError: Could not start video source	AbortError: Starting videoinput failed	CouldNotStartVideoSource	Turn off other video
All Other Errors						Generic

Examples

React

We have found Google Meet to have one of the best onboarding experiences for camera and microphone permissions. They do a good job of explaining permissions, showing how to allow permissions, and deep linking into System Preferences or Settings when needed. This example, built with React and Material UI, closely copies the Google Meet experience.

You can try it out by going to examples/react-example and running:

yarn install && yarn start

Roadmap

Allow custom constraints for getUserMedia().

Handle errors for when there are no camera or microphone devices.

Provide support for mobile browsers.

Dependencies

bowser

A small, fast and rich-API browser/platform/engine detector for both browser and node.

Resources

• Common getUserMedia() Errors - A great read explaining various errors when calling getUserMedia() on Firefox vs Chrome. (slightly outdated)
• MediaDevices.getUserMedia() - Mozilla's documentation for the reason behind errors when calling getUserMedia().
• StackOverflow: reprompt for permissions with getUserMedia() after initial denial - Some good responses for ways to ask for permission to access camera and microphone.

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