feat: add an option specifying when source buffer removals happen (#6242

)

Increases the default required removal duration from `0.01` => `1.0`.

Closes #6240.

demo/config.js

@@ -420,6 +420,8 @@ shakaDemo.Config = class {
             /* canBeDecimal= */ true)
         .addNumberInput_('Buffer Behind', 'streaming.bufferBehind',
             /* canBeDecimal= */ true)
+        .addNumberInput_('Eviction Goal', 'streaming.evictionGoal',
+            /* canBeDecimal= */ true)
         .addNumberInput_('Safe Seek Offset', 'streaming.safeSeekOffset',
             /* canBeDecimal= */ true)
         .addNumberInput_('Stall Threshold', 'streaming.stallThreshold',

externs/shaka/player.js

@@ -1137,6 +1137,7 @@ shaka.extern.ManifestConfiguration;
  *   rebufferingGoal: number,
  *   bufferingGoal: number,
  *   bufferBehind: number,
+ *   evictionGoal: number,
  *   ignoreTextStreamFailures: boolean,
  *   alwaysStreamText: boolean,
  *   startAtSegmentBoundary: boolean,
@@ -1198,6 +1199,10 @@ shaka.extern.ManifestConfiguration;
  *   The maximum number of seconds of content that the StreamingEngine will keep
  *   in buffer behind the playhead when it appends a new media segment.
  *   The StreamingEngine will evict content to meet this limit.
+ * @property {number} evictionGoal
+ *   The minimum duration in seconds of buffer overflow the StreamingEngine
+ *   requires to start removing content from the buffer.
+ *   Values less than <code>1.0</code> are not recommended.
  * @property {boolean} ignoreTextStreamFailures
  *   If <code>true</code>, the player will ignore text stream failures and
  *   continue playing other streams.

lib/media/streaming_engine.js

@@ -2346,13 +2346,14 @@ shaka.media.StreamingEngine = class {
     const bufferedBehind = presentationTime - startTime;
 
     const overflow = bufferedBehind - bufferBehind;
-    // See: https://github.com/shaka-project/shaka-player/issues/2982
-    if (overflow <= 0.01) {
+    // See: https://github.com/shaka-project/shaka-player/issues/6240
+    if (overflow <= this.config_.evictionGoal) {
       shaka.log.v2(logPrefix,
           'buffer behind okay:',
           'presentationTime=' + presentationTime,
           'bufferedBehind=' + bufferedBehind,
           'bufferBehind=' + bufferBehind,
+          'evictionGoal=' + this.config_.evictionGoal,
           'underflow=' + Math.abs(overflow));
       return;
     }
@@ -2362,6 +2363,7 @@ shaka.media.StreamingEngine = class {
         'presentationTime=' + presentationTime,
         'bufferedBehind=' + bufferedBehind,
         'bufferBehind=' + bufferBehind,
+        'evictionGoal=' + this.config_.evictionGoal,
         'overflow=' + overflow);
 
     await this.playerInterface_.mediaSourceEngine.remove(mediaState.type,

lib/util/player_configuration.js

@@ -191,6 +191,7 @@ shaka.util.PlayerConfiguration = class {
       rebufferingGoal: 2,
       bufferingGoal: 10,
       bufferBehind: 30,
+      evictionGoal: 1,
       ignoreTextStreamFailures: false,
       alwaysStreamText: false,
       startAtSegmentBoundary: false,