fix: Change quality only when adding the last partial segment and it …

…is fast switching (#6114)

externs/shaka/abr_manager.js

@@ -96,6 +96,15 @@ shaka.extern.AbrManager = class {
    */
   segmentDownloaded(deltaTimeMs, numBytes, allowSwitch) {}
 
+  /**
+   * Notifies the ABR that it is a time to suggest new streams. This is used by
+   * the Player when it finishes adding the last partial segment of a fast
+   * switching stream.
+   *
+   * @exportDoc
+   */
+  trySuggestStreams() {}
+
   /**
    * Gets an estimate of the current bandwidth in bit/sec.  This is used by the
    * Player to generate stats.

lib/abr/simple_abr_manager.js

@@ -320,6 +320,17 @@ shaka.abr.SimpleAbrManager = class {
   }
 
 
+  /**
+   * @override
+   * @export
+   */
+  trySuggestStreams() {
+    if ((this.lastTimeChosenMs_ != null) && this.enabled_) {
+      this.suggestStreams_();
+    }
+  }
+
+
   /**
    * @override
    * @export

lib/media/segment_prefetch.js

@@ -97,6 +97,10 @@ shaka.media.SegmentPrefetch = class {
         this.segmentPrefetchMap_.set(reference, segmentPrefetchOperation);
       }
       this.prefetchPosTime_ = reference.startTime;
+      if (this.stream_.fastSwitching && reference.isPartial() &&
+          reference.isLastPartial()) {
+        break;
+      }
       reference = iterator.next().value;
     }
   }

lib/media/streaming_engine.js

@@ -1488,8 +1488,7 @@ shaka.media.StreamingEngine = class {
           JSON.stringify(buffered));
 
       if (!mediaState.waitingToClearBuffer) {
-        this.playerInterface_.onSegmentAppended(
-            reference.startTime, reference.endTime, mediaState.type);
+        this.playerInterface_.onSegmentAppended(reference, mediaState.stream);
       }
 
       // Update right away.
@@ -2540,8 +2539,8 @@ shaka.media.StreamingEngine = class {
  *   onError: function(!shaka.util.Error),
  *   onEvent: function(!Event),
  *   onManifestUpdate: function(),
- *   onSegmentAppended: function(number, number,
- *     !shaka.util.ManifestParserUtils.ContentType),
+ *   onSegmentAppended: function(!shaka.media.SegmentReference,
+ *     !shaka.extern.Stream),
  *   onInitSegmentAppended: function(!number,!shaka.media.InitSegmentReference),
  *   beforeAppendSegment: function(
  *     shaka.util.ManifestParserUtils.ContentType,!BufferSource):Promise,
@@ -2566,10 +2565,9 @@ shaka.media.StreamingEngine = class {
  *   Called when an event occurs that should be sent to the app.
  * @property {function()} onManifestUpdate
  *   Called when an embedded 'emsg' box should trigger a manifest update.
- * @property {function(number, number,
- *   !shaka.util.ManifestParserUtils.ContentType)} onSegmentAppended
+ * @property {function(!shaka.media.SegmentReference,
+ *     !shaka.extern.Stream)} onSegmentAppended
  *   Called after a segment is successfully appended to a MediaSource.
- *   The parameters are the start and end time.
  * @property
  *  {function(!number, !shaka.media.InitSegmentReference)} onInitSegmentAppended
  *   Called when an init segment is appended to a MediaSource.

lib/net/networking_engine.js

@@ -700,7 +700,7 @@ shaka.net.NetworkingEngine = class extends shaka.util.FakeEventTarget {
       const segment = context.segment;
       const stream = context.stream;
       if (segment && stream && stream.fastSwitching) {
-        if (segment.isPartial() && !segment.isLastPartial()) {
+        if (segment.isPartial()) {
           return false;
         }
       }

lib/player.js

@@ -1858,6 +1858,12 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
             'Please use an AbrManager with setCmsdManager function.');
         this.abrManager_.setCmsdManager = () => {};
       }
+      if (typeof this.abrManager_.trySuggestStreams != 'function') {
+        shaka.Deprecate.deprecateFeature(5,
+            'AbrManager',
+            'Please use an AbrManager with trySuggestStreams function.');
+        this.abrManager_.trySuggestStreams = () => {};
+      }
       this.abrManager_.configure(this.config_.abr);
     }
 
@@ -2915,8 +2921,13 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
       onError: (error) => this.onError_(error),
       onEvent: (event) => this.dispatchEvent(event),
       onManifestUpdate: () => this.onManifestUpdate_(),
-      onSegmentAppended: (start, end, contentType) => {
-        this.onSegmentAppended_(start, end, contentType);
+      onSegmentAppended: (reference, stream) => {
+        this.onSegmentAppended_(
+            reference.startTime, reference.endTime, stream.type);
+        if (this.abrManager_ && stream.fastSwitching &&
+            reference.isPartial() && reference.isLastPartial()) {
+          this.abrManager_.trySuggestStreams();
+        }
       },
       onInitSegmentAppended: (position, initSegment) => {
         const mediaQuality = initSegment.getMediaQuality();