feat: do fast rendition changes on fullscreen changes and user actions (#1074)

Deprecate smoothQualityChange_ on the MPC, but otherwise, always do fast quality change whenever a user requests a rendition change and on fullscreen change

README.md

@@ -402,20 +402,16 @@ If true, this will take the device pixel ratio into account when doing rendition
 This setting is `false` by default.
 
 ##### smoothQualityChange
+* NOTE: DEPRECATED
 * Type: `boolean`
 * can be used as a source option
 * can be used as an initialization option
 
-When the `smoothQualityChange` property is set to `true`, a manual quality
-change triggered via the [representations API](#vhsrepresentations) will use
-smooth quality switching rather than the default fast (buffer-ejecting)
-quality switching. Using smooth quality switching will mean no loading spinner
-will appear during quality switches, but will cause quality switches to only
-be visible after a few seconds.
+smoothQualityChange is deprecated and will be removed in the next major version of VHS.
 
-Note that this _only_ affects quality changes triggered via the representations
-API; automatic quality switches based on available bandwidth will always be
-smooth switches.
+Instead of its prior behavior, smoothQualityChange will now call fastQualityChange, which
+clears the buffer, chooses a new rendition, and starts loading content from the current
+playhead position.
 
 ##### allowSeeksWithinUnsafeLiveWindow
 * Type: `boolean`

scripts/index-demo-page.js

@@ -21,7 +21,7 @@
       rep.playlist.disabled = rep.id !== id;
     });
 
-    window.mpc.smoothQualityChange_();
+    window.mpc.fastQualityChange_();
   });
   var hlsOptGroup = document.querySelector('[label="hls"]');
   var dashOptGroup = document.querySelector('[label="dash"]');

src/master-playlist-controller.js

@@ -848,16 +848,10 @@ export class MasterPlaylistController extends videojs.EventTarget {
    * removing already buffered content
    *
    * @private
+   * @deprecated
    */
   smoothQualityChange_(media = this.selectPlaylist()) {
-    if (media === this.masterPlaylistLoader_.media()) {
-      return;
-    }
-
-    this.switchMedia_(media, 'smooth-quality');
-
-    this.mainSegmentLoader_.resetLoader();
-    // don't need to reset audio as it is reset when media changes
+    this.fastQualityChange_(media);
   }
 
   /**

src/videojs-http-streaming.js

@@ -590,7 +590,12 @@ class VhsHandler extends Component {
         document.msFullscreenElement;
 
       if (fullscreenElement && fullscreenElement.contains(this.tech_.el())) {
-        this.masterPlaylistController_.smoothQualityChange_();
+        this.masterPlaylistController_.fastQualityChange_();
+      } else {
+        // When leaving fullscreen, since the in page pixel dimensions should be smaller
+        // than full screen, see if there should be a rendition switch down to preserve
+        // bandwidth.
+        this.masterPlaylistController_.checkABR_();
       }
     });
 
@@ -708,6 +713,10 @@ class VhsHandler extends Component {
       this.tech_.setCurrentTime(time);
     };
 
+    if (this.options_.smoothQualityChange) {
+      videojs.log.warn('smoothQualityChange is deprecated and will be removed in the next major version');
+    }
+
     this.masterPlaylistController_ = new MasterPlaylistController(this.options_);
 
     const playbackWatcherOptions = videojs.mergeOptions(

test/configuration.test.js

@@ -36,11 +36,6 @@ const options = [{
   default: 4194304,
   test: 5,
   alt: 555
-}, {
-  name: 'smoothQualityChange',
-  default: false,
-  test: true,
-  alt: false
 }, {
   name: 'useBandwidthFromLocalStorage',
   default: false,

test/master-playlist-controller.test.js

@@ -430,8 +430,10 @@ QUnit.test(
   }
 );
 
-QUnit.test('resyncs SegmentLoader for a smooth quality change', function(assert) {
-  let resyncs = 0;
+// Since smoothQualityChange is deprecated, calls to smoothQualityChange_ should call
+// fastQualityChange_.
+QUnit.test('smoothQualityChange_ calls fastQualityChange_', function(assert) {
+  let fastQualityChangeCalls = 0;
 
   this.masterPlaylistController.mediaSource.trigger('sourceopen');
   // master
@@ -439,135 +441,15 @@ QUnit.test('resyncs SegmentLoader for a smooth quality change', function(assert)
   // media
   this.standardXHRResponse(this.requests.shift());
 
-  const segmentLoader = this.masterPlaylistController.mainSegmentLoader_;
-  const originalResync = segmentLoader.resyncLoader;
-
-  segmentLoader.resyncLoader = function() {
-    resyncs++;
-    originalResync.call(segmentLoader);
-  };
-
   this.masterPlaylistController.selectPlaylist = () => {
     return this.masterPlaylistController.master().playlists[0];
   };
 
-  this.masterPlaylistController.smoothQualityChange_();
-
-  assert.equal(resyncs, 1, 'resynced the segmentLoader');
-
-  // verify stats
-  assert.equal(this.player.tech_.vhs.stats.bandwidth, 4194304, 'default bandwidth');
-});
-
-QUnit.test(
-  'does not resync the segmentLoader when no smooth quality change occurs',
-  function(assert) {
-    let resyncs = 0;
-
-    // master
-    this.standardXHRResponse(this.requests.shift());
-    // media
-    this.standardXHRResponse(this.requests.shift());
-    this.masterPlaylistController.mediaSource.trigger('sourceopen');
-
-    const segmentLoader = this.masterPlaylistController.mainSegmentLoader_;
-    const originalResync = segmentLoader.resyncLoader;
-
-    segmentLoader.resyncLoader = function() {
-      resyncs++;
-      originalResync.call(segmentLoader);
-    };
+  this.masterPlaylistController.fastQualityChange_ = () => fastQualityChangeCalls++;
 
-    this.masterPlaylistController.smoothQualityChange_();
-
-    assert.equal(resyncs, 0, 'did not resync the segmentLoader');
-    // verify stats
-    assert.equal(this.player.tech_.vhs.stats.bandwidth, 4194304, 'default bandwidth');
-  }
-);
-
-QUnit.test('smooth quality change resyncs audio segment loader', function(assert) {
-  this.requests.length = 0;
-  this.player.dispose();
-  this.player = createPlayer();
-  this.player.src({
-    src: 'alternate-audio-multiple-groups.m3u8',
-    type: 'application/vnd.apple.mpegurl'
-  });
-
-  this.clock.tick(1);
-
-  const masterPlaylistController = this.player.tech_.vhs.masterPlaylistController_;
-
-  masterPlaylistController.selectPlaylist = () => {
-    return masterPlaylistController.master().playlists[0];
-  };
-
-  // master
-  this.standardXHRResponse(this.requests.shift());
-  // media
-  this.standardXHRResponse(this.requests.shift());
-
-  masterPlaylistController.mediaSource.trigger('sourceopen');
-
-  this.clock.tick(1);
-
-  this.player.audioTracks()[0].enabled = true;
-
-  let resyncs = 0;
-  let resets = 0;
-  const realReset = masterPlaylistController.audioSegmentLoader_.resetLoader;
-
-  masterPlaylistController.audioSegmentLoader_.resetLoader = function() {
-    resets++;
-    realReset.call(this);
-  };
-
-  const originalResync = masterPlaylistController.audioSegmentLoader_.resyncLoader;
-
-  masterPlaylistController.audioSegmentLoader_.resyncLoader = function() {
-    resyncs++;
-    originalResync.call(masterPlaylistController.audioSegmentLoader_);
-  };
-
-  masterPlaylistController.smoothQualityChange_();
-  assert.equal(resyncs, 0, 'does not resync the audio segment loader when media same');
-
-  // force different media
-  masterPlaylistController.selectPlaylist = () => {
-    return masterPlaylistController.master().playlists[1];
-  };
+  this.masterPlaylistController.smoothQualityChange_();
 
-  assert.equal(this.requests.length, 3, 'three requests');
-  assert.ok(
-    this.requests[0].url.endsWith('eng/prog_index.m3u8'),
-    'requests eng playlist'
-  );
-  assert.ok(this.requests[1].url.endsWith('lo/main.mp4'), 'correct segment url');
-  assert.equal(
-    this.requests[1].requestHeaders.Range,
-    'bytes=0-603',
-    'requests init segment byte range'
-  );
-  assert.ok(this.requests[2].url.endsWith('lo/main.mp4'), 'correct segment url');
-  assert.equal(
-    this.requests[2].requestHeaders.Range,
-    'bytes=604-118754',
-    'requests segment byte range'
-  );
-  assert.notOk(this.requests[0].aborted, 'did not abort alt audio playlist request');
-  assert.notOk(this.requests[1].aborted, 'did not abort init request');
-  assert.notOk(this.requests[2].aborted, 'did not abort segment request');
-  masterPlaylistController.smoothQualityChange_();
-  assert.equal(this.requests.length, 4, 'added a request for new media');
-  assert.notOk(this.requests[0].aborted, 'did not abort alt audio playlist request');
-  assert.ok(this.requests[1].aborted, 'aborted init segment request');
-  assert.ok(this.requests[2].aborted, 'aborted segment request');
-  assert.equal(resyncs, 0, 'does not resync the audio segment loader yet');
-  // new media request
-  this.standardXHRResponse(this.requests[3]);
-  assert.equal(resyncs, 1, 'resyncs the audio segment loader when media changes');
-  assert.equal(resets, 0, 'does not reset the audio segment loader when media changes');
+  assert.equal(fastQualityChangeCalls, 1, 'called fastQualityChange_');
 });
 
 QUnit.test('resets everything for a fast quality change', function(assert) {
@@ -995,11 +877,11 @@ QUnit.test('audio segment loader is reset on audio track change', function(asser
 
   let resyncs = 0;
   let resets = 0;
-  const realReset = masterPlaylistController.audioSegmentLoader_.resetLoader;
+  const realReset = masterPlaylistController.audioSegmentLoader_.resetEverything;
 
-  masterPlaylistController.audioSegmentLoader_.resetLoader = function() {
+  masterPlaylistController.audioSegmentLoader_.resetEverything = function(done) {
     resets++;
-    realReset.call(this);
+    realReset.call(this, done);
   };
 
   const originalResync = masterPlaylistController.audioSegmentLoader_.resyncLoader;
@@ -1032,6 +914,7 @@ QUnit.test('audio segment loader is reset on audio track change', function(asser
   assert.equal(resyncs, 0, 'does not resync the audio segment loader yet');
 
   this.player.audioTracks()[1].enabled = true;
+  this.clock.tick(1);
 
   assert.equal(this.requests.length, 4, 'added a request for new media');
   assert.ok(this.requests[0].aborted, 'aborted old alt audio playlist request');
@@ -4801,18 +4684,19 @@ QUnit.test('can pass or select a playlist for smoothQualityChange_', function(as
 
   mpc.smoothQualityChange_(mpc.master().playlists[1]);
   assert.deepEqual(calls, {
-    resetEverything: 0,
+    // should reset everything since smoothQualityChange_ calls fastQualityChange_
+    resetEverything: 1,
     media: 1,
     selectPlaylist: 0,
-    resyncLoader: 1
+    resyncLoader: 0
   }, 'calls expected function when passed a playlist');
 
   mpc.smoothQualityChange_();
   assert.deepEqual(calls, {
-    resetEverything: 0,
+    resetEverything: 2,
     media: 2,
     selectPlaylist: 1,
-    resyncLoader: 2
+    resyncLoader: 0
   }, 'calls expected function when not passed a playlist');
 });
 

test/segment-loader.test.js

@@ -4344,6 +4344,9 @@ QUnit.module('SegmentLoader', function(hooks) {
         // smoothQualityChange will reset loader after changing renditions, so need to
         // mimic that behavior here in order for content to be overlayed over already
         // buffered content.
+        //
+        // Now that smoothQualityChange is removed, this behavior can be mimicked by
+        // calling resetLoader.
         loader.resetLoader();
         this.clock.tick(1);
 

test/videojs-http-streaming.test.js

@@ -5389,7 +5389,7 @@ QUnit.test('stats are reset on dispose', function(assert) {
 
 // mocking the fullscreenElement no longer works, find another way to mock
 // fullscreen behavior(without user gesture)
-QUnit.skip('detects fullscreen and triggers a smooth quality change', function(assert) {
+QUnit.skip('detects fullscreen and triggers a fast quality change', function(assert) {
   const vhs = VhsSourceHandler.handleSource({
     src: 'manifest/master.m3u8',
     type: 'application/vnd.apple.mpegurl'
@@ -5405,7 +5405,7 @@ QUnit.skip('detects fullscreen and triggers a smooth quality change', function(a
     }
   });
 
-  vhs.masterPlaylistController_.smoothQualityChange_ = function() {
+  vhs.masterPlaylistController_.fastQualityChange_ = function() {
     qualityChanges++;
   };
 
@@ -5415,12 +5415,19 @@ QUnit.skip('detects fullscreen and triggers a smooth quality change', function(a
 
   assert.equal(qualityChanges, 1, 'made a fast quality change');
 
+  let checkABRCalls = 0;
+
+  vhs.masterPlaylistController_.checkABR_ = () => checkABRCalls++;
+
   // don't do a fast quality change when returning from fullscreen;
-  // allow the video element to rescale the already buffered video
+  //
+  // do check the current rendition to see if it should be changed for the next
+  // segment loaded
   document[fullscreenElementName] = null;
   Events.trigger(document, 'fullscreenchange');
 
   assert.equal(qualityChanges, 1, 'did not make another quality change');
+  assert.equal(checkABRCalls, 1, 'called to check the ABR');
   vhs.dispose();
 });