feat: Stop setting playbackRate to 0 to control buffering state when …

…streaming.rebufferingGoal = 0 (#7617)

Close #7602

demo/config.js

@@ -460,7 +460,8 @@ shakaDemo.Config = class {
         .addNumberInput_('Duration Backoff', 'streaming.durationBackoff',
             /* canBeDecimal= */ true)
         .addNumberInput_('Rebuffering Goal', 'streaming.rebufferingGoal',
-            /* canBeDecimal= */ true)
+            /* canBeDecimal= */ true,
+            /* canBeZero= */ true)
         .addNumberInput_('Buffer Behind', 'streaming.bufferBehind',
             /* canBeDecimal= */ true)
         .addNumberInput_('Eviction Goal', 'streaming.evictionGoal',

docs/tutorials/config.md

@@ -75,7 +75,7 @@ player.getConfiguration();
        failureCallback: Function
        ignoreTextStreamFailures: false
        alwaysStreamText: false
-       rebufferingGoal: 2
+       rebufferingGoal: 0
        retryParameters: Object
        startAtSegmentBoundary: false
        safeSeekOffset: 5
@@ -103,7 +103,7 @@ player.getConfiguration().preferredAudioLanguage
 // check buffering goal, which is 2 minutes:
 player.getConfiguration().streaming.bufferingGoal
 
-// check rebuffering goal, which is still the default of 2 seconds:
+// check rebuffering goal, which is still the default of 0 seconds:
 player.getConfiguration().streaming.rebufferingGoal
 
 // set the rebuffering goal to 15 seconds and revert buffering goal to default:
@@ -124,7 +124,6 @@ buffering settings) while some will not have any effect until the next call to
 
 With `.streaming.lowLatencyMode` set to true,
 `.streaming.inaccurateManifestTolerance` is set to 0 by default,
-`.streaming.rebufferingGoal` is set to 0.01 by default,
 `.streaming.segmentPrefetchLimit` is set to 2 by default,
 `.streaming.updateIntervalSeconds` is set to 0.1 by default,
 `.streaming.maxDisabledTime` is set to 1 by default,
@@ -141,7 +140,6 @@ player.configure({
   streaming: {
     lowLatencyMode: true,
     inaccurateManifestTolerance: 0,
-    rebufferingGoal: 0.01,
     segmentPrefetchLimit: 2,
     updateIntervalSeconds: 0.1,
     maxDisabledTime: 1,

externs/shaka/player.js

@@ -1590,8 +1590,9 @@ shaka.extern.LiveSyncConfiguration;
  *   buffer before it can begin playback or can continue playback after it has
  *   entered into a buffering state (i.e., after it has depleted one more
  *   more of its buffers).
+ *   When the value is 0, the playback rate is not used to control the buffer.
  *   <br>
- *   Defaults to <code>2</code>.
+ *   Defaults to <code>0</code>.
  * @property {number} bufferingGoal
  *   The number of seconds of content that the StreamingEngine will attempt to
  *   buffer ahead of the playhead. This value must be greater than or equal to

lib/media/buffering_observer.js

@@ -67,9 +67,10 @@ shaka.media.BufferingObserver = class {
     const threshold = this.thresholds_.get(this.previousState_);
 
     const oldState = this.previousState_;
-    const newState = (bufferedToEnd || bufferLead >= threshold) ?
-                     (State.SATISFIED) :
-                     (State.STARVING);
+    const newState =
+        (bufferedToEnd || (bufferLead >= threshold && bufferLead > 0)) ?
+        (State.SATISFIED) :
+        (State.STARVING);
 
     // Save the new state now so that calls to |getState| from any callbacks
     // will be accurate.

lib/player.js

@@ -3634,7 +3634,10 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
 
     this.bufferPoller_ = new shaka.util.Timer(() => {
       this.pollBufferState_();
-    }).tickEvery(/* seconds= */ 0.25);
+    });
+    if (this.config_.streaming.rebufferingGoal) {
+      this.bufferPoller_.tickEvery(/* seconds= */ 0.25);
+    }
     this.loadEventManager_.listen(mediaElement, 'waiting',
         (e) => this.pollBufferState_());
     this.loadEventManager_.listen(mediaElement, 'stalled',
@@ -3643,6 +3646,8 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
         (e) => this.pollBufferState_());
     this.loadEventManager_.listen(mediaElement, 'progress',
         (e) => this.pollBufferState_());
+    this.loadEventManager_.listen(mediaElement, 'seeked',
+        (e) => this.pollBufferState_());
   }
 
   /**
@@ -4030,19 +4035,16 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
     }
 
     // If lowLatencyMode is enabled, and inaccurateManifestTolerance and
-    // rebufferingGoal and segmentPrefetchLimit and baseDelay and
+    // segmentPrefetchLimit and baseDelay and
     // autoCorrectDrift and maxDisabledTime are not specified, set
-    // inaccurateManifestTolerance to 0 and rebufferingGoal to 0.01 and
+    // inaccurateManifestTolerance to 0 and and
     // segmentPrefetchLimit to 2 and updateIntervalSeconds to 0.1 and and
     // baseDelay to 100 and autoCorrectDrift to false and maxDisabledTime
     // to 1 by default for low latency streaming.
     if (config['streaming'] && config['streaming']['lowLatencyMode']) {
       if (config['streaming']['inaccurateManifestTolerance'] == undefined) {
         config['streaming']['inaccurateManifestTolerance'] = 0;
       }
-      if (config['streaming']['rebufferingGoal'] == undefined) {
-        config['streaming']['rebufferingGoal'] = 0.01;
-      }
       if (config['streaming']['segmentPrefetchLimit'] == undefined) {
         config['streaming']['segmentPrefetchLimit'] = 2;
       }
@@ -4204,6 +4206,13 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
     if (this.bufferObserver_) {
       this.updateBufferingSettings_(this.config_.streaming.rebufferingGoal);
     }
+    if (this.bufferPoller_) {
+      if (!this.config_.streaming.rebufferingGoal) {
+        this.bufferPoller_.stop();
+      } else {
+        this.bufferPoller_.tickEvery(/* seconds= */ 0.25);
+      }
+    }
 
     if (this.manifest_) {
       shaka.Player.applyPlayRange_(this.manifest_.presentationTimeline,
@@ -6721,7 +6730,12 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
     const loaded = this.stats_ && this.bufferObserver_ && this.playhead_;
 
     if (loaded) {
-      this.playRateController_.setBuffering(isBuffering);
+      if (this.config_.streaming.rebufferingGoal == 0) {
+        // Disable buffer control with playback rate
+        this.playRateController_.setBuffering(/* isBuffering= */ false);
+      } else {
+        this.playRateController_.setBuffering(isBuffering);
+      }
       if (this.cmcdManager_) {
         this.cmcdManager_.setBuffering(isBuffering);
       }

lib/util/player_configuration.js

@@ -201,9 +201,7 @@ shaka.util.PlayerConfiguration = class {
             [error],
             undefined);
       },
-      // When low latency streaming is enabled, rebufferingGoal will default to
-      // 0.01 if not specified.
-      rebufferingGoal: 2,
+      rebufferingGoal: 0,
       bufferingGoal: 10,
       bufferBehind: 30,
       evictionGoal: 1,

test/player_unit.js

@@ -1291,7 +1291,6 @@ describe('Player', () => {
       player.configure({
         streaming: {
           lowLatencyMode: true,
-          rebufferingGoal: 1,
           inaccurateManifestTolerance: 1,
           segmentPrefetchLimit: 1,
           updateIntervalSeconds: 10,
@@ -1314,7 +1313,6 @@ describe('Player', () => {
           },
         },
       });
-      expect(player.getConfiguration().streaming.rebufferingGoal).toBe(1);
       expect(player.getConfiguration().streaming.inaccurateManifestTolerance)
           .toBe(1);
       expect(player.getConfiguration().streaming.segmentPrefetchLimit).toBe(1);
@@ -1330,12 +1328,10 @@ describe('Player', () => {
       expect(player.getConfiguration().drm.retryParameters.baseDelay)
           .toBe(2000);
 
-      // When low latency streaming gets enabled, rebufferingGoal will default
-      // to 0.01 if unless specified, inaccurateManifestTolerance will
-      // default to 0 unless specified, and segmentPrefetchLimit will
+      // When low latency streaming gets enabled, inaccurateManifestTolerance
+      // will default to 0 unless specified, and segmentPrefetchLimit will
       // default to 2 unless specified.
       player.configure('streaming.lowLatencyMode', true);
-      expect(player.getConfiguration().streaming.rebufferingGoal).toBe(0.01);
       expect(player.getConfiguration().streaming.inaccurateManifestTolerance)
           .toBe(0);
       expect(player.getConfiguration().streaming.segmentPrefetchLimit).toBe(2);