Fallback to target SN if PDT is missing in live start frag look up

Do not set previous segment to "initSegment" as a sequence number is expected Fix demo timeline setup and updates of LL-HLS streams with query params video-dev#3473
moshior · Feb 22, 2021 · 8687cf1 · 8687cf1
1 parent 874fc7a
commit 8687cf1
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Showing 6 changed files with 38 additions and 13 deletions.
diff --git a/demo/chart/timeline-chart.ts b/demo/chart/timeline-chart.ts
@@ -283,13 +283,11 @@ export class TimelineChart {
   updateLevelOrTrack(details: LevelDetails) {
     const { targetduration, totalduration, url } = details;
     const { datasets } = this.chart.data;
-    // eslint-disable-next-line no-restricted-properties
-    const deliveryDirectivePattern = /[?&]_HLS_(?:msn|part|skip)=[^?&]+/g;
     const levelDataSet = arrayFind(
       datasets,
       (dataset) =>
-        dataset.url?.toString().replace(deliveryDirectivePattern, '') ===
-        url.replace(deliveryDirectivePattern, '')
+        stripDeliveryDirectives(url) ===
+        stripDeliveryDirectives(dataset.url || '')
     );
     if (!levelDataSet) {
       return;
@@ -659,6 +657,19 @@ export class TimelineChart {
   }
 }
 
+function stripDeliveryDirectives(url: string): string {
+  try {
+    const webUrl: URL = new self.URL(url);
+    webUrl.searchParams.delete('_HLS_msn');
+    webUrl.searchParams.delete('_HLS_part');
+    webUrl.searchParams.delete('_HLS_skip');
+    webUrl.searchParams.sort();
+    return webUrl.href;
+  } catch (e) {
+    return url.replace(/[?&]_HLS_(?:msn|part|skip)=[^?&]+/g, '');
+  }
+}
+
 function datasetWithDefaults(options) {
   return Object.assign(
     {

diff --git a/demo/main.js b/demo/main.js
@@ -1583,7 +1583,7 @@ function addChartEventListeners(hls) {
     chart
   );
   hls.on(
-    Hls.Events.MANIFEST_LOADED,
+    Hls.Events.MANIFEST_PARSED,
     (eventName, data) => {
       const { levels } = data;
       chart.removeType('level');

diff --git a/src/controller/audio-stream-controller.ts b/src/controller/audio-stream-controller.ts
@@ -590,10 +590,12 @@ class AudioStreamController
       );
       return;
     }
-    this.fragPrevious = frag;
-    if (this.audioSwitch && frag.sn !== 'initSegment') {
-      this.audioSwitch = false;
-      this.hls.trigger(Events.AUDIO_TRACK_SWITCHED, { id: this.trackId });
+    if (frag.sn !== 'initSegment') {
+      this.fragPrevious = frag;
+      if (this.audioSwitch) {
+        this.audioSwitch = false;
+        this.hls.trigger(Events.AUDIO_TRACK_SWITCHED, { id: this.trackId });
+      }
     }
     this.fragBufferedComplete(frag, part);
   }

diff --git a/src/controller/base-stream-controller.ts b/src/controller/base-stream-controller.ts
@@ -792,7 +792,8 @@ export default class BaseStreamController
           fragPrevious.endProgramDateTime,
           config.maxFragLookUpTolerance
         );
-      } else {
+      }
+      if (!frag) {
         // SN does not need to be accurate between renditions, but depending on the packaging it may be so.
         const targetSN = (fragPrevious.sn as number) + 1;
         if (

diff --git a/src/controller/stream-controller.ts b/src/controller/stream-controller.ts
@@ -842,7 +842,9 @@ export default class StreamController
     this.fragLastKbps = Math.round(
       (8 * stats.total) / (stats.buffering.end - stats.loading.first)
     );
-    this.fragPrevious = frag;
+    if (frag.sn !== 'initSegment') {
+      this.fragPrevious = frag;
+    }
     this.fragBufferedComplete(frag, part);
   }
 
@@ -876,15 +878,23 @@ export default class StreamController
             );
             // @ts-ignore - frag is potentially null according to TS here
             this.warn(
-              `Fragment ${frag?.sn} of level ${frag?.level} failed to load, retrying in ${delay}ms`
+              `Fragment ${frag.sn} of level ${frag.level} failed to load, retrying in ${delay}ms`
             );
             this.retryDate = self.performance.now() + delay;
             // retry loading state
             // if loadedmetadata is not set, it means that we are emergency switch down on first frag
             // in that case, reset startFragRequested flag
             if (!this.loadedmetadata) {
               this.startFragRequested = false;
-              this.nextLoadPosition = this.startPosition;
+              const details = this.levels
+                ? this.levels[frag.level].details
+                : null;
+              if (details?.live) {
+                this.startPosition = -1;
+                this.setStartPosition(details, 0);
+              } else {
+                this.nextLoadPosition = this.startPosition;
+              }
             }
             this.fragLoadError++;
             this.state = State.FRAG_LOADING_WAITING_RETRY;

diff --git a/src/loader/m3u8-parser.ts b/src/loader/m3u8-parser.ts
@@ -490,6 +490,7 @@ export default class M3U8Parser {
       totalduration -= prevFrag.duration;
       level.fragmentHint = prevFrag;
     } else {
+      assignProgramDateTime(frag, prevFrag);
       level.fragmentHint = frag;
     }
     const fragmentLength = fragments.length;