Fix last segment in live removed "context changed" error

src/controller/base-playlist-controller.ts

@@ -1,7 +1,7 @@
 import type Hls from '../hls';
 import type { NetworkComponentAPI } from '../types/component-api';
 import { getSkipValue, HlsSkip, HlsUrlParameters } from '../types/level';
-import { computeReloadInterval } from './level-helper';
+import { computeReloadInterval, mergeDetails } from './level-helper';
 import { logger } from '../utils/logger';
 import type { LevelDetails } from '../loader/level-details';
 import type { MediaPlaylist } from '../types/media-playlist';
@@ -11,7 +11,6 @@ import type {
   TrackLoadedData,
 } from '../types/events';
 import { ErrorData } from '../types/events';
-import * as LevelHelper from './level-helper';
 import { Events } from '../events';
 import { ErrorTypes } from '../errors';
 
@@ -128,7 +127,7 @@ export default class BasePlaylistController implements NetworkComponentAPI {
       }
       // Merge live playlists to adjust fragment starts and fill in delta playlist skipped segments
       if (previousDetails && details.fragments.length > 0) {
-        LevelHelper.mergeDetails(previousDetails, details);
+        mergeDetails(previousDetails, details);
       }
       if (!this.canLoad || !details.live) {
         return;

src/controller/base-stream-controller.ts

@@ -4,7 +4,6 @@ import { Bufferable, BufferHelper } from '../utils/buffer-helper';
 import { logger } from '../utils/logger';
 import { Events } from '../events';
 import { ErrorDetails } from '../errors';
-import * as LevelHelper from './level-helper';
 import { ChunkMetadata } from '../types/transmuxer';
 import { appendUint8Array } from '../utils/mp4-tools';
 import { alignStream } from '../utils/discontinuities';
@@ -13,6 +12,11 @@ import {
   findFragmentByPTS,
   findFragWithCC,
 } from './fragment-finders';
+import {
+  getFragmentWithSN,
+  getPartWith,
+  updateFragPTSDTS,
+} from './level-helper';
 import TransmuxerInterface from '../demux/transmuxer-interface';
 import { Fragment, Part } from '../loader/fragment';
 import FragmentLoader, {
@@ -654,11 +658,10 @@ export default class BaseStreamController
       return null;
     }
     const level = levels[levelIndex];
-    const part =
-      partIndex > -1 ? LevelHelper.getPartWith(level, sn, partIndex) : null;
+    const part = partIndex > -1 ? getPartWith(level, sn, partIndex) : null;
     const frag = part
       ? part.fragment
-      : LevelHelper.getFragmentWithSN(level, sn);
+      : getFragmentWithSN(level, sn, this.fragCurrent);
     if (!frag) {
       return null;
     }
@@ -1088,7 +1091,7 @@ export default class BaseStreamController
       levelLastLoaded !== null ? levels![levelLastLoaded] : null;
 
     // FIXME: If not for `shouldAlignOnDiscontinuities` requiring fragPrevious.cc,
-    //  this could all go in LevelHelper.mergeDetails
+    //  this could all go in level-helper mergeDetails()
     let sliding = 0;
     if (previousDetails && details.fragments.length > 0) {
       sliding = details.fragments[0].start;
@@ -1310,7 +1313,7 @@ export default class BaseStreamController
           }
           const drift = partial
             ? 0
-            : LevelHelper.updateFragPTSDTS(
+            : updateFragPTSDTS(
                 details,
                 frag,
                 info.startPTS,

src/controller/level-helper.ts

@@ -446,7 +446,11 @@ export function computeReloadInterval(
   return Math.round(estimatedTimeUntilUpdate);
 }
 
-export function getFragmentWithSN(level: Level, sn: number): Fragment | null {
+export function getFragmentWithSN(
+  level: Level,
+  sn: number,
+  fragCurrent: Fragment | null
+): Fragment | null {
   if (!level || !level.details) {
     return null;
   }
@@ -460,6 +464,9 @@ export function getFragmentWithSN(level: Level, sn: number): Fragment | null {
   if (fragment && fragment.sn === sn) {
     return fragment;
   }
+  if (sn < levelDetails.startSN && fragCurrent && fragCurrent.sn === sn) {
+    return fragCurrent;
+  }
   return null;
 }