fix(ui): Play video with the previous speed after pause

When we change the video play rate via UI, and pause and play the
video, it resumes playing at 1. That's caused by 'cancelTrickPlay'.

We can set the defaultPlaybackRate when changing the play rate, and
use that value when we resume playing.

Closes shaka-project#3261

Change-Id: Ifc200697ea956e3257ae3371886bbb5c9c03338f

lib/media/play_rate_controller.js

@@ -88,6 +88,15 @@ shaka.media.PlayRateController = class {
     return this.rate_;
   }
 
+  /**
+   * Get the default play rate of the playback.
+   *
+   * @return {number}
+   */
+  getDefaultRate() {
+    return this.harness_.getDefaultRate();
+  }
+
   /**
    * Reapply the effects of |this.rate_| and |this.active_| to the media
    * element. This will only update the rate via the harness if the desired rate
@@ -161,6 +170,7 @@ shaka.media.PlayRateController = class {
 /**
  * @typedef {{
  *   getRate: function():number,
+ *   getDefaultRate: function():number,
  *   setRate: function(number),
  *   movePlayhead: function(number)
  * }}
@@ -173,6 +183,9 @@ shaka.media.PlayRateController = class {
  * @property {function():number} getRate
  *   Get the current playback rate being seen by the user.
  *
+ * @property {function():number} getDefaultRate
+ *   Get the default playback rate that the user should see.
+ *
  * @property {function(number)} setRate
  *   Set the playback rate that the user should see.
  *

lib/player.js

@@ -1802,6 +1802,7 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
 
     this.playRateController_ = new shaka.media.PlayRateController({
       getRate: () => has.mediaElement.playbackRate,
+      getDefaultRate: () => has.mediaElement.defaultPlaybackRate,
       setRate: (rate) => { has.mediaElement.playbackRate = rate; },
       movePlayhead: (delta) => { has.mediaElement.currentTime += delta; },
     });
@@ -2084,6 +2085,7 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
 
     this.playRateController_ = new shaka.media.PlayRateController({
       getRate: () => has.mediaElement.playbackRate,
+      getDefaultRate: () => has.mediaElement.defaultPlaybackRate,
       setRate: (rate) => { has.mediaElement.playbackRate = rate; },
       movePlayhead: (delta) => { has.mediaElement.currentTime += delta; },
     });
@@ -3173,13 +3175,14 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
    * @export
    */
   cancelTrickPlay() {
+    const defaultPlaybackRate = this.playRateController_.getDefaultRate();
     if (this.loadMode_ == shaka.Player.LoadMode.SRC_EQUALS) {
-      this.playRateController_.set(1);
+      this.playRateController_.set(defaultPlaybackRate);
     }
 
     if (this.loadMode_ == shaka.Player.LoadMode.MEDIA_SOURCE) {
-      this.playRateController_.set(1);
-      this.abrManager_.playbackRateChanged(1);
+      this.playRateController_.set(defaultPlaybackRate);
+      this.abrManager_.playbackRateChanged(defaultPlaybackRate);
       this.streamingEngine_.setTrickPlay(false);
     }
   }

test/media/play_rate_controller_unit.js

@@ -12,6 +12,8 @@ describe('PlayRateController', () => {
   /** @type {!jasmine.Spy} */
   let getPlayRateSpy;
   /** @type {!jasmine.Spy} */
+  let getDefaultPlayRateSpy;
+  /** @type {!jasmine.Spy} */
   let setPlayRateSpy;
   /** @type {!jasmine.Spy} */
   let movePlayheadSpy;
@@ -24,6 +26,7 @@ describe('PlayRateController', () => {
 
   beforeEach(() => {
     getPlayRateSpy = jasmine.createSpy('getPlaybackRate');
+    getDefaultPlayRateSpy = jasmine.createSpy('getDefaultPlaybackRate');
     setPlayRateSpy = jasmine.createSpy('setPlaybackRate');
     movePlayheadSpy = jasmine.createSpy('movePlayhead');
 
@@ -36,6 +39,7 @@ describe('PlayRateController', () => {
 
     const harness = {
       getRate: shaka.test.Util.spyFunc(getPlayRateSpy),
+      getDefaultRate: shaka.test.Util.spyFunc(getDefaultPlayRateSpy),
       setRate: shaka.test.Util.spyFunc(setPlayRateSpy),
       movePlayhead: shaka.test.Util.spyFunc(movePlayheadSpy),
     };

ui/playback_rate_selection.js

@@ -124,6 +124,7 @@ shaka.ui.PlaybackRateSelection = class extends shaka.ui.SettingsMenu {
 
       this.eventManager.listen(button, 'click', () => {
         this.video.playbackRate = this.playbackRates_.get(rateStr);
+        this.video.defaultPlaybackRate = this.playbackRates_.get(rateStr);
       });
 
       this.menu.appendChild(button);