Add MediaHandler

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

src/webrtc/mediaHandler.ts

@@ -0,0 +1,115 @@
+/*
+Copyright 2015, 2016 OpenMarket Ltd
+Copyright 2017 New Vector Ltd
+Copyright 2019, 2020 The Matrix.org Foundation C.I.C.
+Copyright 2021 Šimon Brandner <simon.bra.ag@gmail.com>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { logger } from "../logger";
+
+export class MediaHandler {
+    private audioInput: string;
+    private videoInput: string;
+
+    /**
+     * Set an audio input device to use for MatrixCalls
+     * @param {string} deviceId the identifier for the device
+     * undefined treated as unset
+     */
+    public setAudioInput(deviceId: string): void {
+        this.audioInput = deviceId;
+    }
+
+    /**
+     * Set a video input device to use for MatrixCalls
+     * @param {string} deviceId the identifier for the device
+     * undefined treated as unset
+     */
+    public setVideoInput(deviceId: string): void {
+        this.videoInput = deviceId;
+    }
+
+    /**
+     * @returns {MediaStream} based on passed parameters
+     */
+    public async getUserMediaStream(audio: boolean, video: boolean): Promise<MediaStream> {
+        const constraints = this.getUserMediaContraints(audio, video);
+        logger.log("Getting user media with constraints", constraints);
+        return await navigator.mediaDevices.getUserMedia(constraints);
+    }
+
+    /**
+     * @returns {MediaStream} based on passed parameters
+     */
+    public async getScreensharingStream(desktopCapturerSourceId: string): Promise<MediaStream> {
+        const screenshareConstraints = this.getScreenshareContraints(desktopCapturerSourceId);
+        if (!screenshareConstraints) return null;
+
+        if (desktopCapturerSourceId) {
+            // We are using Electron
+            logger.debug("Getting screen stream using getUserMedia()...");
+            return await navigator.mediaDevices.getUserMedia(screenshareConstraints);
+        } else {
+            // We are not using Electron
+            logger.debug("Getting screen stream using getDisplayMedia()...");
+            return await navigator.mediaDevices.getDisplayMedia(screenshareConstraints);
+        }
+    }
+
+    private getUserMediaContraints(audio: boolean, video: boolean): MediaStreamConstraints {
+        const isWebkit = !!navigator.webkitGetUserMedia;
+
+        return {
+            audio: audio
+                ? {
+                    deviceId: this.audioInput ? { ideal: this.audioInput } : undefined,
+                }
+                : false,
+            video: video
+                ? {
+                    deviceId: this.videoInput ? { ideal: this.videoInput } : undefined,
+                    /* We want 640x360.  Chrome will give it only if we ask exactly,
+                   FF refuses entirely if we ask exactly, so have to ask for ideal
+                   instead
+                   XXX: Is this still true?
+                 */
+                    width: isWebkit ? { exact: 640 } : { ideal: 640 },
+                    height: isWebkit ? { exact: 360 } : { ideal: 360 },
+                }
+                : false,
+        };
+    }
+
+    private getScreenshareContraints(desktopCapturerSourceId?: string): DesktopCapturerConstraints {
+        if (desktopCapturerSourceId) {
+            logger.debug("Using desktop capturer source", desktopCapturerSourceId);
+            return {
+                audio: false,
+                video: {
+                    mandatory: {
+                        chromeMediaSource: "desktop",
+                        chromeMediaSourceId: desktopCapturerSourceId,
+                    },
+                },
+            };
+        } else {
+            logger.debug("Not using desktop capturer source");
+            return {
+                audio: false,
+                video: true,
+            };
+        }
+    }
+}