feat: Add support for ManagedMediaSource 'startstreaming' and 'endstr…

…eam' event handling (#1542)

src/playlist-controller.js

@@ -215,6 +215,7 @@ export class PlaylistController extends videojs.EventTarget {
       // Airplay source not yet implemented. Remote playback must be disabled.
       this.tech_.el_.disableRemotePlayback = true;
       this.mediaSource = new window.ManagedMediaSource();
+
       videojs.log('Using ManagedMediaSource');
     } else if (window.MediaSource) {
       this.mediaSource = new window.MediaSource();
@@ -223,12 +224,16 @@ export class PlaylistController extends videojs.EventTarget {
     this.handleDurationChange_ = this.handleDurationChange_.bind(this);
     this.handleSourceOpen_ = this.handleSourceOpen_.bind(this);
     this.handleSourceEnded_ = this.handleSourceEnded_.bind(this);
+    this.load = this.load.bind(this);
+    this.pause = this.pause.bind(this);
 
     this.mediaSource.addEventListener('durationchange', this.handleDurationChange_);
 
     // load the media source into the player
     this.mediaSource.addEventListener('sourceopen', this.handleSourceOpen_);
     this.mediaSource.addEventListener('sourceended', this.handleSourceEnded_);
+    this.mediaSource.addEventListener('startstreaming', this.load);
+    this.mediaSource.addEventListener('endstreaming', this.pause);
     // we don't have to handle sourceclose since dispose will handle termination of
     // everything, and the MediaSource should not be detached without a proper disposal
 
@@ -1056,14 +1061,31 @@ export class PlaylistController extends videojs.EventTarget {
    */
   load() {
     this.mainSegmentLoader_.load();
+
     if (this.mediaTypes_.AUDIO.activePlaylistLoader) {
       this.audioSegmentLoader_.load();
     }
+
     if (this.mediaTypes_.SUBTITLES.activePlaylistLoader) {
       this.subtitleSegmentLoader_.load();
     }
   }
 
+  /**
+   * Call pause on our SegmentLoaders
+   */
+  pause() {
+    this.mainSegmentLoader_.pause();
+
+    if (this.mediaTypes_.AUDIO.activePlaylistLoader) {
+      this.audioSegmentLoader_.pause();
+    }
+
+    if (this.mediaTypes_.SUBTITLES.activePlaylistLoader) {
+      this.subtitleSegmentLoader_.pause();
+    }
+  }
+
   /**
    * Re-tune playback quality level for the current player
    * conditions. This method will perform destructive actions like removing

test/playlist-controller.test.js

@@ -7693,3 +7693,39 @@ QUnit.test('uses ManagedMediaSource only when opted in', function(assert) {
   mmsSpy.restore();
   mms.restore();
 });
+
+QUnit.test('ManagedMediaSource startstreaming and endstreaming events start and pause segment loading respectively', function(assert) {
+  const mms = useFakeManagedMediaSource();
+  const options = {
+    src: 'test.m3u8',
+    tech: this.player.tech_,
+    player_: this.player,
+    experimentalUseMMS: true
+  };
+
+  const controller = new PlaylistController(options);
+
+  controller.mediaTypes_.AUDIO.activePlaylistLoader = {};
+  controller.mediaTypes_.SUBTITLES.activePlaylistLoader = {};
+
+  const mainLoadSpy = sinon.spy(controller.mainSegmentLoader_, 'load');
+  const audioLoadSpy = sinon.spy(controller.audioSegmentLoader_, 'load');
+  const subtitleLoadSpy = sinon.spy(controller.subtitleSegmentLoader_, 'load');
+  const mainPauseSpy = sinon.spy(controller.mainSegmentLoader_, 'pause');
+  const audioPauseSpy = sinon.spy(controller.audioSegmentLoader_, 'pause');
+  const subtitlePauseSpy = sinon.spy(controller.subtitleSegmentLoader_, 'pause');
+
+  controller.mediaSource.trigger('startstreaming');
+
+  assert.ok(mainLoadSpy.calledOnce, 'Segment loading started on startstreaming event');
+  assert.ok(audioLoadSpy.calledOnce, 'Audio segment loading started on startstreaming event');
+  assert.ok(subtitleLoadSpy.calledOnce, 'Subtitle segment loading started on startstreaming event');
+
+  controller.mediaSource.trigger('endstreaming');
+
+  assert.ok(mainPauseSpy.calledOnce, 'Main segment loading paused on endstreaming event');
+  assert.ok(audioPauseSpy.calledOnce, 'Audio segment loading paused on endstreaming event');
+  assert.ok(subtitlePauseSpy.calledOnce, 'Subtitle segment loading paused on endstreaming event');
+
+  mms.restore();
+});