ability to specify webrtc audio/video inputs for the lib to request

src/matrix.js

@@ -73,6 +73,23 @@ module.exports.InteractiveAuth = require("./interactive-auth");
  */
 module.exports.createNewMatrixCall = require("./webrtc/call").createNewMatrixCall;
 
+
+/**
+ * Set an audio input device to use for MatrixCalls
+ * @function
+ * @param {string=} deviceId the identifier for the device
+ * undefined treated as unset
+ */
+module.exports.setMatrixCallAudioInput = require('./webrtc/call').setAudioInput;
+/**
+ * Set a video input device to use for MatrixCalls
+ * @function
+ * @param {string=} deviceId the identifier for the device
+ * undefined treated as unset
+ */
+module.exports.setMatrixCallVideoInput = require('./webrtc/call').setVideoInput;
+
+
 // expose the underlying request object so different environments can use
 // different request libs (e.g. request or browser-request)
 let request;

src/webrtc/call.js

@@ -1187,16 +1187,25 @@ const _getChromeScreenSharingConstraints = function(call) {
 const _getUserMediaVideoContraints = function(callType) {
     switch (callType) {
         case 'voice':
-            return ({audio: true, video: false});
+            return {
+                audio: {
+                    deviceId: audioInput ? {exact: audioInput} : undefined,
+                }, video: false,
+            };
         case 'video':
-            return ({audio: true, video: {
+            return {
+                audio: {
+                    deviceId: audioInput ? {exact: audioInput} : undefined,
+                }, video: {
+                    deviceId: videoInput ? {exact: videoInput} : undefined,
                     mandatory: {
                         minWidth: 640,
                         maxWidth: 640,
                         minHeight: 360,
                         maxHeight: 360,
                     },
-            }});
+                },
+            };
     }
 };
 
@@ -1228,6 +1237,22 @@ const forAllTracksOnStream = function(s, f) {
 /** The MatrixCall class. */
 module.exports.MatrixCall = MatrixCall;
 
+let audioInput;
+let videoInput;
+/**
+ * Set an audio input device to use for MatrixCalls
+ * @function
+ * @param {string=} deviceId the identifier for the device
+ * undefined treated as unset
+ */
+module.exports.setAudioInput = function(deviceId) { audioInput = deviceId; };
+/**
+ * Set a video input device to use for MatrixCalls
+ * @function
+ * @param {string=} deviceId the identifier for the device
+ * undefined treated as unset
+ */
+module.exports.setVideoInput = function(deviceId) { videoInput = deviceId; };
 
 /**
  * Create a new Matrix call for the browser.