Merge pull request video-dev#3852 from video-dev/bugfix/async-frag-lo…

…ad-abort-loop

Prevent async abort handler from causing current fragment to be reloaded

src/controller/base-stream-controller.ts

@@ -205,9 +205,10 @@ export default class BaseStreamController
       const fragStartOffset = fragCurrent.start - tolerance;
       const fragEndOffset =
         fragCurrent.start + fragCurrent.duration + tolerance;
-      // check if the seek position will be out of currently loaded frag range : if out cancel frag load, if in, don't do anything
-      if (currentTime < fragStartOffset || currentTime > fragEndOffset) {
-        if (fragCurrent.loader) {
+      const pastFragment = currentTime > fragEndOffset;
+      // check if the seek position is past current fragment, and if so abort loading
+      if (currentTime < fragStartOffset || pastFragment) {
+        if (pastFragment && fragCurrent.loader) {
           this.log(
             'seeking outside of buffer while fragment load in progress, cancel fragment load'
           );
@@ -226,8 +227,8 @@ export default class BaseStreamController
       this.nextLoadPosition = this.startPosition = currentTime;
     }
 
-    // tick to speed up processing
-    this.tick();
+    // Async tick to speed up processing
+    this.tickImmediate();
   }
 
   protected onMediaEnded() {
@@ -356,6 +357,9 @@ export default class BaseStreamController
     endOffset: number,
     type: SourceBufferName | null = null
   ) {
+    if (!(startOffset - endOffset)) {
+      return;
+    }
     // When alternate audio is playing, the audio-stream-controller is responsible for the audio buffer. Otherwise,
     // passing a null type flushes both buffers
     const flushScope: BufferFlushingData = { startOffset, endOffset, type };
@@ -1111,7 +1115,7 @@ export default class BaseStreamController
   }
 
   private handleFragLoadAborted(frag: Fragment, part: Part | undefined) {
-    if (this.transmuxer && frag.sn !== 'initSegment') {
+    if (this.transmuxer && frag.sn !== 'initSegment' && frag.stats.aborted) {
       this.warn(
         `Fragment ${frag.sn}${part ? ' part' + part.index : ''} of level ${
           frag.level

src/task-loop.ts

@@ -112,13 +112,17 @@ export default class TaskLoop {
       // -> schedule a call on the next main loop iteration to process this task processing request
       if (this._tickCallCount > 1) {
         // make sure only one timer exists at any time at max
-        this.clearNextTick();
-        this._tickTimer = self.setTimeout(this._boundTick, 0);
+        this.tickImmediate();
       }
       this._tickCallCount = 0;
     }
   }
 
+  public tickImmediate(): void {
+    this.clearNextTick();
+    this._tickTimer = self.setTimeout(this._boundTick, 0);
+  }
+
   /**
    * For subclass to implement task logic
    * @abstract

tests/unit/controller/subtitle-stream-controller.js

@@ -20,6 +20,7 @@ describe('SubtitleStreamController', function () {
 
   beforeEach(function () {
     hls = new Hls({});
+    mediaMock.currentTime = 0;
     fragmentTracker = new FragmentTracker(hls);
     subtitleStreamController = new SubtitleStreamController(
       hls,
@@ -126,7 +127,18 @@ describe('SubtitleStreamController', function () {
 
   describe('onMediaSeeking', function () {
     it('nulls fragPrevious when seeking away from fragCurrent', function () {
-      subtitleStreamController.fragCurrent = { start: 1000, duration: 10 };
+      subtitleStreamController.fragCurrent = {
+        start: 1000,
+        duration: 10,
+        loader: {
+          abort: () => {
+            this.state.aborted = true;
+          },
+          stats: {
+            aborted: false,
+          },
+        },
+      };
       subtitleStreamController.fragPrevious = {};
       subtitleStreamController.onMediaSeeking();
       expect(subtitleStreamController.fragPrevious).to.not.exist;