Use video contiguity as the anchor signal, drop the cross-level consecutive rule

src/demux/transmuxer-interface.ts

@@ -210,16 +210,10 @@ export default class TransmuxerInterface {
       snDiff === 0 &&
       chunkMeta.id > 1 &&
       chunkMeta.id === lastFrag?.stats.chunkCount;
-    const nextInSequence =
-      snDiff === 1 ||
-      (snDiff === 0 && (partDiff === 1 || (progressive && partDiff <= 0)));
-    const contiguous = !trackSwitch && nextInSequence;
-    const consecutive =
-      nextInSequence ||
-      (trackSwitch &&
-        lastFrag !== null &&
-        Math.abs(timeOffset - (this.part ? this.part.end : lastFrag.end)) <=
-          this.hls.config.maxFragLookUpTolerance);
+    const contiguous =
+      !trackSwitch &&
+      (snDiff === 1 ||
+        (snDiff === 0 && (partDiff === 1 || (progressive && partDiff <= 0))));
     const now = self.performance.now();
 
     if (trackSwitch || snDiff || frag.stats.parsing.start === 0) {
@@ -238,7 +232,6 @@ export default class TransmuxerInterface {
       trackSwitch,
       timeOffset,
       initSegmentChange,
-      consecutive,
     );
     if (!contiguous || discontinuity || initSegmentChange) {
       this.hls.logger
@@ -248,7 +241,6 @@ export default class TransmuxerInterface {
         discontinuity: ${discontinuity}
         trackSwitch: ${trackSwitch}
         contiguous: ${contiguous}
-        consecutive: ${consecutive}
         accurateTimeOffset: ${accurateTimeOffset}
         timeOffset: ${timeOffset}
         initSegmentChange: ${initSegmentChange}`);

src/demux/transmuxer.ts

@@ -106,7 +106,6 @@ export default class Transmuxer {
 
     const {
       contiguous,
-      consecutive,
       discontinuity,
       trackSwitch,
       accurateTimeOffset,
@@ -182,7 +181,7 @@ export default class Transmuxer {
     }
 
     if (discontinuity || initSegmentChange || resetMuxers) {
-      this.resetInitialTimestamp(defaultInitPts, consecutive);
+      this.resetInitialTimestamp(defaultInitPts);
     }
 
     if (!contiguous) {
@@ -201,7 +200,6 @@ export default class Transmuxer {
     const currentState = this.currentTransmuxState;
 
     currentState.contiguous = true;
-    currentState.consecutive = true;
     currentState.discontinuity = false;
     currentState.trackSwitch = false;
 
@@ -306,16 +304,13 @@ export default class Transmuxer {
     chunkMeta.transmuxing.executeEnd = now();
   }
 
-  resetInitialTimestamp(
-    defaultInitPts: TimestampOffset | null,
-    consecutive: boolean = false,
-  ) {
+  resetInitialTimestamp(defaultInitPts: TimestampOffset | null) {
     const { demuxer, remuxer } = this;
     if (!demuxer || !remuxer) {
       return;
     }
     demuxer.resetTimeStamp(defaultInitPts);
-    remuxer.resetTimeStamp(defaultInitPts, consecutive);
+    remuxer.resetTimeStamp(defaultInitPts);
   }
 
   resetContiguity() {
@@ -575,7 +570,6 @@ export class TransmuxState {
   public trackSwitch: boolean;
   public timeOffset: number;
   public initSegmentChange: boolean;
-  public consecutive: boolean;
 
   constructor(
     discontinuity: boolean,
@@ -584,14 +578,12 @@ export class TransmuxState {
     trackSwitch: boolean,
     timeOffset: number,
     initSegmentChange: boolean,
-    consecutive: boolean = contiguous,
   ) {
     this.discontinuity = discontinuity;
     this.contiguous = contiguous;
     this.accurateTimeOffset = accurateTimeOffset;
     this.trackSwitch = trackSwitch;
     this.timeOffset = timeOffset;
     this.initSegmentChange = initSegmentChange;
-    this.consecutive = consecutive;
   }
 }

src/remux/mp4-remuxer.ts

@@ -77,7 +77,6 @@ export default class MP4Remuxer extends Logger implements Remuxer {
   private _initDTS: TimestampOffset | null = null;
   private nextVideoTs: number | null = null;
   private nextAudioTs: number | null = null;
-  private isConsecutive: boolean = false;
   private videoSampleDuration: number | null = null;
   private isAudioContiguous: boolean = false;
   private isVideoContiguous: boolean = false;
@@ -105,10 +104,7 @@ export default class MP4Remuxer extends Logger implements Remuxer {
     this.config = this.videoTrackConfig = this._initPTS = this._initDTS = null;
   }
 
-  resetTimeStamp(
-    defaultTimeStamp: TimestampOffset | null,
-    consecutive: boolean = false,
-  ) {
+  resetTimeStamp(defaultTimeStamp: TimestampOffset | null) {
     const initPTS = this._initPTS;
     if (
       !initPTS ||
@@ -119,11 +115,10 @@ export default class MP4Remuxer extends Logger implements Remuxer {
       defaultTimeStamp.timescale !== initPTS.timescale
     ) {
       this.log(
-        `Reset initPTS: ${initPTS ? timestampToString(initPTS) : initPTS} > ${defaultTimeStamp ? timestampToString(defaultTimeStamp) : defaultTimeStamp} consecutive: ${consecutive}`,
+        `Reset initPTS: ${initPTS ? timestampToString(initPTS) : initPTS} > ${defaultTimeStamp ? timestampToString(defaultTimeStamp) : defaultTimeStamp}`,
       );
     }
 
-    this.isConsecutive = consecutive;
     this._initPTS = this._initDTS = defaultTimeStamp;
   }
 
@@ -492,7 +487,7 @@ export default class MP4Remuxer extends Logger implements Remuxer {
           initDTS = Math.min(initDTS as number, videoInitDTS);
           // Bind initPTS to the lowest DTS across tracks to prevent negative timestamps
           const videoInit =
-            !_initPTS && this.isConsecutive ? videoInitPTS : videoInitDTS;
+            !_initPTS && this.isVideoContiguous ? videoInitPTS : videoInitDTS;
           initPTS = Math.min(initPTS as number, videoInit);
         }
       }

src/types/remuxer.ts

@@ -35,10 +35,7 @@ export interface Remuxer {
     videoCodec: string | undefined,
     decryptdata: DecryptData | null,
   ): void;
-  resetTimeStamp(
-    defaultInitPTS: TimestampOffset | null,
-    consecutive?: boolean,
-  ): void;
+  resetTimeStamp(defaultInitPTS: TimestampOffset | null): void;
   resetNextTimestamp(): void;
   destroy(): void;
 }