Fix regressions in live playlist advancement (from #6692 and follow-up …

…#6857) (#6872)
video-dev · Nov 28, 2024 · 6e0656a · 6e0656a
1 parent 19a4c01
commit 6e0656a
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Showing 2 changed files with 20 additions and 19 deletions.
diff --git a/src/utils/level-helper.ts b/src/utils/level-helper.ts
@@ -425,15 +425,14 @@ export function adjustSliding(
   let sliding = 0;
   if (advancedOrStable && delta < oldFragments.length) {
     sliding = oldFragments[delta].start;
+  } else if (advancedOrStable && newDetails.startSN === oldDetails.endSN + 1) {
+    sliding = oldDetails.fragmentEnd;
   } else if (advancedOrStable && matchingStableVariantOrRendition) {
-    // align new start with old end (updated playlist start sequence is past end sequence of last update)
-    sliding = oldDetails.edge;
-  } else if (
-    !newDetails.skippedSegments &&
-    newDetails.fragments[0].start === 0
-  ) {
+    // align with expected position (updated playlist start sequence is past end sequence of last update)
+    sliding = oldDetails.fragmentStart + delta * newDetails.levelTargetDuration;
+  } else if (!newDetails.skippedSegments && newDetails.fragmentStart === 0) {
     // align new start with old (playlist switch has a sequence with no overlap and should not be used for alignment)
-    sliding = oldDetails.fragments[0].start;
+    sliding = oldDetails.fragmentStart;
   } else {
     // new details already has a sliding offset or has skipped segments
     return;

diff --git a/tests/unit/controller/level-helper.ts b/tests/unit/controller/level-helper.ts
@@ -41,6 +41,8 @@ const generatePlaylist = (sequenceNumbers, offset = 0, duration = 5) => {
   const playlist = new LevelDetails('');
   playlist.startSN = sequenceNumbers[0];
   playlist.endSN = sequenceNumbers[sequenceNumbers.length - 1];
+  playlist.targetduration = duration + 1;
+  playlist.averagetargetduration = duration;
   playlist.fragments = sequenceNumbers.map((n, i) => {
     const frag = new Fragment(PlaylistLevelType.MAIN, '');
     frag.sn = n;
@@ -158,12 +160,12 @@ describe('LevelHelper Tests', function () {
       expect(actual).to.deep.equal([10, 15, 20]);
     });
 
-    it('applies minimal sliding when no common segments exist', function () {
+    it('applies expected sliding when no common segments exist', function () {
       const oldPlaylist = generatePlaylist([1, 2, 3]);
       const newPlaylist = generatePlaylist([5, 6, 7]);
       adjustSliding(oldPlaylist, newPlaylist);
       const actual = newPlaylist.fragments.map((f) => f.start);
-      expect(actual).to.deep.equal([15, 20, 25]);
+      expect(actual).to.deep.equal([20, 25, 30]);
     });
 
     it('applies minimal sliding when segments meet but do not overlap', function () {
@@ -184,12 +186,12 @@ describe('LevelHelper Tests', function () {
       expect(actual).to.deep.equal([5, 10, 15, 20]);
     });
 
-    it('applies minimal sliding when there is no segment overlap', function () {
+    it('applies expected sliding when there is no segment overlap', function () {
       const oldPlaylist = generatePlaylist([1, 2, 3]);
       const newPlaylist = generatePlaylist([5, 6, 7]);
       mergeDetails(oldPlaylist, newPlaylist);
       const actual = newPlaylist.fragments.map((f) => f.start);
-      expect(actual).to.deep.equal([15, 20, 25]);
+      expect(actual).to.deep.equal([20, 25, 30]);
     });
 
     it('matches start when the new playlist starts before the old', function () {
@@ -826,8 +828,8 @@ audio_5441.m4s`;
       mergeDetails(mainDetails1, mainDetails2);
       mergeDetails(audioDetails1, audioDetails2);
       expect(audioDetails2.alignedSliding).to.be.false;
-      expect(mainDetails2.fragmentStart).to.equal(14);
-      expect(audioDetails2.fragmentStart).to.equal(15.518999999999998);
+      expect(mainDetails2.fragmentStart).to.equal(20.0825);
+      expect(audioDetails2.fragmentStart).to.equal(16.0325);
 
       expect(mainDetails2.startCC).to.equal(31);
       expect(audioDetails2.startCC).to.equal(31);
@@ -838,8 +840,8 @@ audio_5441.m4s`;
       audioTrackLoaded(audioDetails2, trackInfo);
 
       expect(audioDetails2.alignedSliding).to.be.true;
-      expect(mainDetails2.fragmentStart).to.equal(14);
-      expect(audioDetails2.fragmentStart).to.equal(14);
+      expect(mainDetails2.fragmentStart).to.equal(20.0825);
+      expect(audioDetails2.fragmentStart).to.equal(20.0825);
     });
 
     it('aligns playlist on track update', function () {
@@ -856,15 +858,15 @@ audio_5441.m4s`;
       mergeDetails(mainDetails1, mainDetails2);
       mergeDetails(audioDetails1, audioDetails2);
       expect(audioDetails2.alignedSliding).to.be.false;
-      expect(mainDetails2.fragmentStart).to.equal(14);
-      expect(audioDetails2.fragmentStart).to.equal(15.518999999999998);
+      expect(mainDetails2.fragmentStart).to.equal(20.0825);
+      expect(audioDetails2.fragmentStart).to.equal(16.0325);
 
       audioTrackLoaded(audioDetails2, trackInfo);
       levelLoaded(mainDetails2, levelInfo);
 
       expect(audioDetails2.alignedSliding).to.be.true;
-      expect(mainDetails2.fragmentStart).to.equal(14);
-      expect(audioDetails2.fragmentStart).to.equal(14);
+      expect(mainDetails2.fragmentStart).to.equal(20.0825);
+      expect(audioDetails2.fragmentStart).to.equal(20.0825);
     });
   });
 });