media-devices-util

What is this package for? To get info about available media devices and work with them. You can:

• list available devices
• get default devices
• get audio/video/screen permissions (mac)
• request for audio/video/screen permissions (mac)

How to use it

Install

npm i -S media-devices-util

Use

Get devices list

const mediaDevicesUtil = require("media-devices-util");

const videoDevices = mediaDevicesUtil.getVideoDevices();
const audioDevices = mediaDevicesUtil.getAudioDevices();

console.log({ audioDevices, videoDevices });

// output on mac:
// {
//     audioDevices: [
//         {
//             id: 'AppleHDAEngineInput:1F,3,0,1,0:1',
//             label: 'Built-in Microphone'
//         }
//     ],
//     videoDevices: [
//         {
//             id: '0x1420000005ac8600',
//             label: 'FaceTime HD Camera (Built-in)'
//         },
//         {
//             id: '69733382',
//             label: 'Capture screen 0'
//         }
//     ]
// }
//
// output on windows:
// {
//     audioDevices: [
//         {
//             id: '0',
//             label: 'Microphone (High Definition Audio Device)',
//             alternativeName: '@device_cm_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\\wave_{B073E9D3-C0A7-4CB0-84E0-F829B281F95F}'
//         }
//     ],
//     videoDevices: [
//         {
//             id: '\\\\?\\usb#vid_203a&pid_fff9&mi_00#6&fafa70b&0&0000#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\\global',
//             label: 'FaceTime HD Camera (Built-in)'',
//             alternativeName: '@device_pnp_\\\\?\\usb#vid_203a&pid_fff9&mi_00#6&fafa70b&0&0000#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\\global'
//         }
//     ]
// }

Request for Camera permissions

const mediaDevicesUtil = require("media-devices-util");

mediaDevicesUtil.requestMediaAuthorization("camera").then((status) => {
  if ("AUTHORIZED" === status) {
    // permissions granted!
  }
});

API

media-devices-util object has the following API:

type TDevice = {
  // For mac:
  // audio/video devices are using the 'uniqueID' property - https://developer.apple.com/documentation/avfoundation/avcapturedevice/1390477-uniqueid
  // screen devices are using the 'CGDirectDisplayID' property - https://developer.apple.com/documentation/coregraphics/cgdirectdisplayid
  // For win:
  // audio devices are using the 'WaveInID' property - https://docs.microsoft.com/en-us/windows/win32/directshow/selecting-a-capture-device
  // video devices are using the 'DevicePath' property - https://docs.microsoft.com/en-us/windows/win32/directshow/selecting-a-capture-device
  id: string;

  // For mac:
  // audio/video devices are using the 'localizedName' property - https://developer.apple.com/documentation/avfoundation/avcapturedevice/1388222-localizedname
  // screen devices are using the 'Capture screen ' prefix plus device id in 'CGGetActiveDisplayList' - https://developer.apple.com/documentation/coregraphics/1454603-cggetactivedisplaylist
  // For win:
  // using the 'FriendlyName' property - https://docs.microsoft.com/en-us/windows/win32/directshow/selecting-a-capture-device
  label: string;

  // For win:
  // using the 'GetDisplayName' method's return value - https://docs.microsoft.com/en-us/windows/win32/api/objidl/nf-objidl-imoniker-getdisplayname
  alternativeName?: string;
}

// AUTHORIZED - permissions granted
// DENIED - permissions denied
// NOT_DETERMINED - permissions not set
declare type TAuthorization = "AUTHORIZED" | "DENIED" | "NOT_DETERMINED";

declare type TMediaType = "camera" | "microphone";

type TMediaDevicesUtil = {
    getDefaultVideoDevice(): TDevice;
    getDefaultAudioDevice(): TDevice;
    getVideoDevices(): TDevice[];
    getAudioDevices(): TDevice[];
    getScreenAuthorizationStatus(): TAuthorization;
    getMediaAuthorizationStatus(mediaType: TMediaType): TAuthorization;
    getMediaAuthorizationStatus(): {
        camera: TAuthorization;
        microphone: TAuthorization;
    };
    requestScreenAuthorization(): TAuthorization;
    requestMediaAuthorization(mediaType: TMediaType): Promise<TAuthorization>;
}

getDefaultVideoDevice

Return type: TDevice

Retrieve the default video input device (camera).

For win, taking the first entry of the IEnumMoniker with the CLSID_VideoInputDeviceCategory parameter.

For mac, using the defaultDeviceWithMediaType:AVMediaTypeVideo method for audio/video devices.

getDefaultAudioDevice

Return type: TDevice

Retrieve the default audio input device (microphone).

For win, using the GetDefaultAudioEndpoint method.

For mac, using the defaultDeviceWithMediaType:AVMediaTypeAudio method.

getVideoDevices

Return type: TDevice[]

Retrieve the default video input devices list (cameras, screens, etc.).

For mac, using the devicesWithMediaType:AVMediaTypeVideo method, and the CGGetActiveDisplayList method for screens.

For win, using the IEnumMoniker with the CLSID_VideoInputDeviceCategory parameter.

getAudioDevices

Return type: TDevice[]

Retrieve the default audio input devices list (microphones, virtual devices, etc.).

For mac, using the devicesWithMediaType:AVMediaTypeAudio method.

For win, using the IEnumMoniker with the CLSID_AudioInputDeviceCategory parameter.

getScreenAuthorizationStatus

Return type: TAuthorization

Retrieve current permissions for screen recording.

For mac, using the CGPreflightScreenCaptureAccess method (>=11.0), or will try to match window processes ids (>=10.15), or will return AUTHORIZED.

For win, will always return AUTHORIZED.

getMediaAuthorizationStatus

Return type: TAuthorization | { camera: TAuthorization; microphone: TAuthorization; }

Arguments: (mediaType?: TMediaType)

Retrieve current permissions for audio and/or video usage. If no args passed - will return authorization status for both audio/video.

For mac, using the authorizationStatusForMediaType method.

For win, will always return AUTHORIZED for any type of media.

requestScreenAuthorization

Return type: TAuthorization

Request for screen recording permissions. Will prompt user to modify screen recording permissions config, if possible, otherwise - will open the System Preferences window with Screen Recording tab opened.

For mac, using the CGRequestScreenCaptureAccess method (>=11.0), or will try to use CGDisplayStreamCreate method (>=10.15), or will return AUTHORIZED.

For win, will always return AUTHORIZED.

requestMediaAuthorization

Return type: Promise<TAuthorization>

Arguments: (mediaType: TMediaType)

Request for microphone or camera recording permissions. Will prompt user to modify screen recording permissions config, if possible, otherwise - will open the System Preferences window with Camera or Microphone tab opened.

For mac, using the requestAccessForMediaType method (>=10.14), or will return AUTHORIZED.

For win, will always return AUTHORIZED for any type of media.

FFMPEG

When using an ffmpeg or other libs to capture audio/video devices, you first need to obtain a list of available devices and their labels (IDs).

And when running ffmpeg to just get the devices list - it takes too long, because a lot of overhead ffmpeg lib actions are taken.

Using media-devices-util is much, much faster.

Usage example

Let's imagine, that we want to capture the default audio and default video device with ffmpeg:

const spawn = require("child_process").spawn;
const mediaDevicesUtil = require("media-devices-util");

const defaultVideoDevice = mediaDevicesUtil.getDefaultVideoDevice();
const defaultAudioDevice = mediaDevicesUtil.getDefaultAudioDevice();

// for MacOS, you can use the 'label' prop, and the item's index (if used with getVideoDevices/getAudioDevices):
const ffmpegWinProcess = spawn("ffmpeg", ["-f", "avfoundation", "-i", `${defaultVideoDevice.label}:${defaultAudioDevice.label}`, "video.mkv"]);

// for Windows, you should use the 'label' or the 'alternativeName' prop:
const ffmpegMacProcess = spawn("ffmpeg", ["-f", "dshow", "-i", `video="${defaultVideoDevice.label}":audio="${defaultAudioDevice.alternativeName}"`, "video.mkv"]);

Alternatives

You can use the ffmpeg's list_devices option (for mac or win), and parse it's output to get the list itself.

Also, you can use other ffmpeg command abstractions (like ffmpeg and fluent-ffmpeg).

In any case, the list_devices in ffmpeg lib is something like a crunch, and the lib itself doesn't provide a programmatic way to enumerate devices.

Or use other ffmpeg nodejs bindings lib.

Next Steps

• Improve Windows API (especially permissions), if possible
• Add listeners for devices and/or permissions

License

MIT License