---title: WebRTC---The WebRTC namespace includes functions that give you access to the input and output media devices available on the users machine. For example, you can use these functions to request permission and get access to the media stream from a webcam, from a microphone, or from a screen sharing.## Functions### checkCameraPermissions▸ Const **checkCameraPermissions**(): PromiseAsynchronously returns whether we have permissions to access the camera.#### ReturnsPromise#### Examplejavascriptawait SignalWire.WebRTC.checkCameraPermissions();// true---### checkMicrophonePermissions▸ Const **checkMicrophonePermissions**(): PromiseAsynchronously returns whether we have permissions to access the microphone.#### ReturnsPromise#### Examplejavascriptawait SignalWire.WebRTC.checkMicrophonePermissions();// true---### checkPermissions▸ Const **checkPermissions**(name?): PromiseAsynchronously returns whether we have permissions to access the specified resource. Some common parameter values for name are camera,microphone, and speaker. In those cases, prefer the dedicated methods[checkCameraPermissions](#checkcamerapermissions), [checkMicrophonePermissions](#checkmicrophonepermissions), and [checkSpeakerPermissions](#checkspeakerpermissions).#### Parameters| Name | Type | Description || :------ | :--------------------- | :-------------------- || name? | DevicePermissionName | Name of the resource. |#### ReturnsPromise#### Examplejavascriptawait SignalWire.WebRTC.checkPermissions(camera);// true: we have permission for using the camera---### checkSpeakerPermissions▸ Const **checkSpeakerPermissions**(): PromiseAsynchronously returns whether we have permissions to access the speakers.#### ReturnsPromise#### Examplejavascriptawait SignalWire.WebRTC.checkSpeakerPermissions();// true---### createCameraDeviceWatcher▸ Const **createCameraDeviceWatcher**(): Promise\>Asynchronously returns an event emitter that notifies changes in all camera devices. This is equivalent to callingcreateDeviceWatcher({ targets: [camera] }), so refer to[createDeviceWatcher](#createdevicewatcher) for additional information about the returned event emitter.#### ReturnsPromise\>---### createDeviceWatcher▸ Const **createDeviceWatcher**(options?): Promise\>Asynchronously returns an event emitter that notifies changes in the devices. The possible events are:- added: A device has been added.- removed: A device has been removed.- updated: A device has been updated.- changed: Any of the previous events occurred.In all cases, your event handler gets as parameter an object e with the following keys:- e.changes: The changed devices. For added, removed, and updated event handlers, you only get the object associated to the respective event (i.e., only a list of added devices, removed devices, or updated devices). For changed event handlers, you get all three lists.- e.devices: The new list of devices.For device-specific helpers, see [createCameraDeviceWatcher](#createcameradevicewatcher), [createMicrophoneDeviceWatcher](#createmicrophonedevicewatcher), and [createSpeakerDeviceWatcher](#createspeakerdevicewatcher).#### Parameters| Name | Type | Description || :-------- | :--------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ || options | CreateDeviceWatcherOptions | If null, the event emitter is associated to all devices for which we have permission. Otherwise, you can pass an object {targets: string}, where the value for key targets is a list of categories. Allowed categories are camera, microphone, and speaker. |#### ReturnsPromise\>#### ExamplesCreating an event listener on the changed event and printing the received parameter after both connecting and disconnecting external headphones:javascriptawait SignalWire.WebRTC.getUserMedia({ audio: true, video: false });h = await SignalWire.WebRTC.createDeviceWatcher();h.on(changed, (c) => console.log(c));Getting notified just for changes about audio input and output devices, ignoring the camera:javascripth = await SignalWire.WebRTC.createDeviceWatcher({ targets: [microphone, speaker],});h.on(changed, (c) => console.log(c));---### createMicrophoneAnalyzer▸ Const **createMicrophoneAnalyzer**(options): PromiseInitializes a microphone analyzer. You can use a MicrophoneAnalyzer to track the input audio volume.To stop the analyzer, please call the destroy() method on the object returned by this method.The returned object emits the following events:- volumeChanged: Instantaneous volume from 0 to 100.- destroyed: The object has been destroyed. You get a parameter describing the reason, which can be null (if you called destroy()), error (in case of errors), or disconnected (if the device was disconnected).#### Parameters| Name | Type | Description || :-------- | :--------------------------------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ || options | string \| MediaStream \| MediaTrackConstraints | Either the id of the device to analyze, or [MediaStreamConstraints](https://developer.mozilla.org/en-US/docs/Web/API/MediaStreamConstraints), or a [MediaStream](https://developer.mozilla.org/en-US/docs/Web/API/MediaStream). |#### ReturnsPromiseAsynchronously returns a MicrophoneAnalyzer.#### Examplejsconst micAnalyzer = await createMicrophoneAnalyzer(device-id);micAnalyzer.on(volumeChanged, (vol) => { console.log(Volume: , vol);});micAnalyzer.on(destroyed, (reason) => { console.log(Microphone analyzer destroyed, reason);});micAnalyzer.destroy();---### createMicrophoneDeviceWatcher▸ Const **createMicrophoneDeviceWatcher**(): Promise\>Asynchronously returns an event emitter that notifies changes in all microphone devices. This is equivalent to callingcreateDeviceWatcher({ targets: [microphone] }), so refer to[createDeviceWatcher](#createdevicewatcher) for additional information about the returned event emitter.#### ReturnsPromise\>---### createSpeakerDeviceWatcher▸ Const **createSpeakerDeviceWatcher**(): Promise\>Asynchronously returns an event emitter that notifies changes in all speaker devices. This is equivalent to callingcreateDeviceWatcher({ targets: [speaker] }), so refer to[createDeviceWatcher](#createdevicewatcher) for additional information about the returned event emitter.#### ReturnsPromise\>---### enumerateDevices▸ Const **enumerateDevices**(): Promise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>Enumerates the media input and output devices available on this device.> 📘> Depending on the browser, some information (such as the label and> deviceId attributes) could be hidden until permission is granted, for> example by calling [getUserMedia](#getusermedia).#### ReturnsPromise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>#### Examplejavascriptawait SignalWire.WebRTC.enumerateDevices();// [// {// deviceId: Rug5Bk...4TMhY=,// kind: videoinput,// label: HD FaceTime Camera,// groupId: EEX/N2...AjrOs=// },// ...// ]---### getCameraDevices▸ Const **getCameraDevices**(): Promise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>Returns an array of camera devices that can be accessed on this device (for which we have permissions).#### ReturnsPromise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>#### Examplejavascriptawait SignalWire.WebRTC.getCameraDevices();// [// {// deviceId: Rug5Bk...4TMhY=,// kind: videoinput,// label: HD FaceTime Camera,// groupId: Su/dzw...ccfnY=// }// ]---### getCameraDevicesWithPermissions▸ Const **getCameraDevicesWithPermissions**(): Promise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>> ⚠️ Deprecated.> Use [getCameraDevices](#getcameradevices) for better cross browser compatibility.After prompting the user for permission, returns an array of camera devices.#### ReturnsPromise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>#### Examplejavascriptawait SignalWire.WebRTC.getCameraDevicesWithPermissions();// [// {// deviceId: Rug5Bk...4TMhY=,// kind: videoinput,// label: HD FaceTime Camera,// groupId: Su/dzw...ccfnY=// }// ]---### getDevices▸ Const **getDevices**(name?, fullList?): Promise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>Enumerates the media input and output devices available on this machine. Ifname is provided, only the devices of the specified kind are returned.Possible values of the name parameters are camera, microphone, andspeaker, which respectively correspond to functions[getCameraDevices](#getcameradevices), [getMicrophoneDevices](#getmicrophonedevices), and [getSpeakerDevices](#getspeakerdevices).#### Parameters| Name | Type | Default value | Description || :--------- | :--------------------- | :------------ | :------------------------------------------------------------------------------------------------------------------------------------------------------- || name? | DevicePermissionName | undefined | Filter for this device category. || fullList | boolean | false | Default to false. Set to true to retrieve the raw list as returned by the browser, which might include multiple, duplicate deviceIds for the same group. |#### ReturnsPromise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>#### Examplejavascriptawait SignalWire.WebRTC.getDevices(camera, true);// [// {// deviceId: 3c4f97...,// kind: videoinput,// label: HD Camera,// groupId: 828fec...// }// ]---### getDevicesWithPermissions▸ Const **getDevicesWithPermissions**(kind?, fullList?): Promise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>> ⚠️ Deprecated.> Use [getDevices](#getdevices) for better cross browser compatibility.After prompting the user for permission, returns an array of media input and output devices available on this machine. If kind is not null, only the devices of the specified kind are returned. Possible values of the kind parameters are camera, microphone, and speaker, which respectively correspond to functions [getCameraDevicesWithPermissions](#getcameradeviceswithpermissions), [getMicrophoneDevicesWithPermissions](#getmicrophonedeviceswithpermissions), and [getSpeakerDevicesWithPermissions](#getspeakerdeviceswithpermissions).#### Parameters| Name | Type | Default value | Description || :--------- | :--------------------- | :------------ | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- || kind? | DevicePermissionName | undefined | Filter for this device category. || fullList | boolean | false | By default, only devices for which we have been granted permissions are returned. To obtain a list of devices regardless of the permissions, pass fullList=true. Note however that some values such as name and deviceId could be omitted. |#### ReturnsPromise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>#### Examplejavascriptawait SignalWire.WebRTC.getDevicesWithPermissions(camera);// [// {// deviceId: Rug5Bk...4TMhY=,// kind: videoinput,// label: HD FaceTime Camera,// groupId: Su/dzw...ccfnY=// }// ]---### getDisplayMedia▸ Const **getDisplayMedia**(constraints?): PromisePrompts the user to share the screen and asynchronously returns a [MediaStream](https://developer.mozilla.org/en-US/docs/Web/API/MediaStream) object associated with a display or part of it.#### Parameters| Name | Type | Description || :------------- | :----------------------- | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- || constraints? | MediaStreamConstraints | An optional [MediaStreamConstraints](https://developer.mozilla.org/en-US/docs/Web/API/MediaStreamConstraints) object specifying requirements for the returned [MediaStream](https://developer.mozilla.org/en-US/docs/Web/API/MediaStream). |#### ReturnsPromise#### Examplejavascriptawait SignalWire.WebRTC.getDisplayMedia(); // MediaStream {id: HCXy..., active: true, ...}---### getMicrophoneDevices▸ Const **getMicrophoneDevices**(): Promise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>Returns an array of microphone devices that can be accessed on this device (for which we have permissions).#### ReturnsPromise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>#### Examplejavascriptawait SignalWire.WebRTC.getMicrophoneDevices();// [// {// deviceId: ADciLf...NYgF8=,// kind: audioinput,// label: Internal Microphone,// groupId: rgZgKM...NW1hU=// }// ]---### getMicrophoneDevicesWithPermissions▸ Const **getMicrophoneDevicesWithPermissions**(): Promise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>> ⚠️ Deprecated.> Use [getMicrophoneDevices](#getmicrophonedevices) for better cross browser compatibility.After prompting the user for permission, returns an array of microphone devices.#### ReturnsPromise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>#### Examplejavascriptawait SignalWire.WebRTC.getMicrophoneDevicesWithPermissions();// [// {// deviceId: ADciLf...NYgF8=,// kind: audioinput,// label: Internal Microphone,// groupId: rgZgKM...NW1hU=// }// ]---### getSpeakerDevices▸ Const **getSpeakerDevices**(): Promise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>Returns an array of speaker devices that can be accessed on this device (for which we have permissions).#### ReturnsPromise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>#### Examplejavascriptawait SignalWire.WebRTC.getSpeakerDevices();// [// {// deviceId: ADciLf...NYgF8=,// kind: audiooutput,// label: External Speaker,// groupId: rgZgKM...NW1hU=// }// ]---### getSpeakerDevicesWithPermissions▸ Const **getSpeakerDevicesWithPermissions**(): Promise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>> ⚠️ Deprecated.> Use [getSpeakerDevices](#getspeakerdevices) for better cross browser compatibility.After prompting the user for permission, returns an array of speaker devices.#### ReturnsPromise<[MediaDeviceInfo](https://developer.mozilla.org/en-US/docs/Web/API/mediadeviceinfo) []\>#### Examplejavascriptawait SignalWire.WebRTC.getSpeakerDevicesWithPermissions();// [// {// deviceId: ADciLf...NYgF8=,// kind: audiooutput,// label: External Speaker,// groupId: rgZgKM...NW1hU=// }// ]---### getSupportedConstraints▸ Const **getSupportedConstraints**(): MediaTrackSupportedConstraintsReturns a dictionary whose fields specify the constrainable properties the user agent understands.#### ReturnsMediaTrackSupportedConstraints#### ExamplejavascriptSignalWire.WebRTC.getSupportedConstraints();// {// aspectRatio: true,// autoGainControl: true,// brightness: true,// channelCount: true,// colorTemperature: true,// ...// }---### getUserMedia▸ Const **getUserMedia**(constraints?): PromisePrompts the user to share one or more media devices and asynchronously returns an associated [MediaStream](https://developer.mozilla.org/en-US/docs/Web/API/MediaStream) object.For more information, see [MediaDevices.getUserMedia()](https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/getUserMedia).#### Parameters| Name | Type | Description || :------------ | :----------------------- | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- || constraints | MediaStreamConstraints | An optional [MediaStreamConstraints](https://developer.mozilla.org/en-US/docs/Web/API/MediaStreamConstraints) object specifying requirements for the returned [MediaStream](https://developer.mozilla.org/en-US/docs/Web/API/MediaStream). |#### ReturnsPromise#### ExamplesTo only request audio media:javascriptawait SignalWire.WebRTC.getUserMedia({ audio: true, video: false });// MediaStream {id: HCXy..., active: true, ...}To request both audio and video, specifying constraints for the video:javascriptconst constraints = { audio: true, video: { width: { min: 1024, ideal: 1280, max: 1920 }, height: { min: 576, ideal: 720, max: 1080 }, },};await SignalWire.WebRTC.getUserMedia(constraints);// MediaStream {id: EDVk..., active: true, ...}---### requestPermissions▸ Const **requestPermissions**(constraints): PromisePrompts the user to grant permissions for the devices matching the specified set of constraints.#### Parameters| Name | Type | Description || :------------ | :----------------------- | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- || constraints | MediaStreamConstraints | An optional [MediaStreamConstraints](https://developer.mozilla.org/en-US/docs/Web/API/MediaStreamConstraints) object specifying requirements for the returned [MediaStream](https://developer.mozilla.org/en-US/docs/Web/API/MediaStream). |#### ReturnsPromise#### ExamplesTo only request audio permissions:javascriptawait SignalWire.WebRTC.requestPermissions({ audio: true, video: false });To request permissions for both audio and video, specifying constraints for the video:javascriptconst constraints = { audio: true, video: { width: { min: 1024, ideal: 1280, max: 1920 }, height: { min: 576, ideal: 720, max: 1080 }, },};await SignalWire.WebRTC.requestPermissions(constraints);---### setMediaElementSinkId▸ Const **setMediaElementSinkId**(el, deviceId): PromiseAssigns the specified audio output device to the specified HTMLMediaElement. The device with id deviceId must be an audio output device. Asynchronously returns whether the operation had success.> 📘> Some browsers do not support output device selection. You can check by> calling [supportsMediaOutput](#supportsmediaoutput).#### Parameters| Name | Type | Description || :--------- | :--------------------------- | :----------------------------- || el | null \| HTMLMediaElement | Target element. || deviceId | string | Id of the audio output device. |#### ReturnsPromise#### Examplejavascriptconst el = document.querySelector(video);const outDevices = await SignalWire.WebRTC.getSpeakerDevicesWithPermissions();await SignalWire.WebRTC.setMediaElementSinkId(el, outDevices[0].deviceId);// true---### stopStream▸ Const **stopStream**(stream?): voidStops all tracks in a specified stream and fires the ended event for each.#### Parameters| Name | Type || :-------- | :---------------------------------------------------------------------------- || stream? | [MediaStream](https://developer.mozilla.org/en-US/docs/Web/API/MediaStream) |#### Returnsvoid---### stopTrack▸ Const **stopTrack**(track): voidStops a specified track. This method is similar to [MediaStreamTrack.stop()](https://developer.mozilla.org/en-US/docs/Web/API/MediaStreamTrack/stop) but this method also fires the ended event.#### Parameters| Name | Type || :------ | :-------------------------------------------------------------------------------------- || track | [MediaStreamTrack](https://developer.mozilla.org/en-US/docs/Web/API/MediaStreamTrack) |#### Returnsvoid---### supportsGetDisplayMedia▸ Const **supportsGetDisplayMedia**(): booleanReturns whether the current environment supports [getDisplayMedia](https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/getDisplayMedia).#### Returnsboolean---### supportsGetUserMedia▸ Const **supportsGetUserMedia**(): booleanReturns whether the current environment supports [getUserMedia](https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/getUserMedia).#### Returnsboolean---### supportsMediaDevices▸ Const **supportsMediaDevices**(): booleanReturns whether the current environment supports the media devices API.#### Returnsboolean---### supportsMediaOutput▸ Const **supportsMediaOutput**(): booleanReturns whether the current environment supports the selection of a media output device.#### Returnsboolean
