diff --git a/demo/chart/timeline-chart.ts b/demo/chart/timeline-chart.ts
index c9517802ff0..0f06269614b 100644
--- a/demo/chart/timeline-chart.ts
+++ b/demo/chart/timeline-chart.ts
@@ -107,7 +107,7 @@ export class TimelineChart {
       if (pos.x > chartArea.left - 11) {
         const scale = this.chartScales[X_AXIS_SECONDS];
         if (event.deltaY) {
-          const direction = event.deltaY / Math.abs(event.deltaY);
+          const direction = -event.deltaY / Math.abs(event.deltaY);
           const normal = Math.min(333, Math.abs(event.deltaY)) / 1000;
           const ease = 1 - (1 - normal) * (1 - normal);
           this.zoom(scale, pos, ease * direction);
diff --git a/src/demux/transmuxer-interface.ts b/src/demux/transmuxer-interface.ts
index b30ec0cfcfe..27eee915f54 100644
--- a/src/demux/transmuxer-interface.ts
+++ b/src/demux/transmuxer-interface.ts
@@ -14,6 +14,7 @@ import type { ChunkMetadata, TransmuxerResult } from '../types/transmuxer';
 import type Hls from '../hls';
 import type { HlsEventEmitter } from '../events';
 import type { PlaylistLevelType } from '../types/loader';
+import type { TypeSupported } from './tsdemuxer';
 
 const MediaSource = getMediaSource() || { isTypeSupported: () => false };
 
@@ -54,7 +55,7 @@ export default class TransmuxerInterface {
     this.observer.on(Events.FRAG_DECRYPTED, forwardMessage);
     this.observer.on(Events.ERROR, forwardMessage);
 
-    const typeSupported = {
+    const typeSupported: TypeSupported = {
       mp4: MediaSource.isTypeSupported('video/mp4'),
       mpeg: MediaSource.isTypeSupported('audio/mpeg'),
       mp3: MediaSource.isTypeSupported('audio/mp4; codecs="mp3"'),
@@ -102,7 +103,8 @@ export default class TransmuxerInterface {
           this.observer,
           typeSupported,
           config,
-          vendor
+          vendor,
+          id
         );
         this.worker = null;
       }
@@ -111,7 +113,8 @@ export default class TransmuxerInterface {
         this.observer,
         typeSupported,
         config,
-        vendor
+        vendor,
+        id
       );
     }
   }
diff --git a/src/demux/transmuxer-worker.ts b/src/demux/transmuxer-worker.ts
index e7ae8442f97..f69145e3a6c 100644
--- a/src/demux/transmuxer-worker.ts
+++ b/src/demux/transmuxer-worker.ts
@@ -24,7 +24,8 @@ export default function TransmuxerWorker(self) {
           observer,
           data.typeSupported,
           config,
-          data.vendor
+          data.vendor,
+          data.id
         );
         enableLogs(config.debug);
         forwardMessage('init', null);
diff --git a/src/demux/transmuxer.ts b/src/demux/transmuxer.ts
index 767a48fcfdc..330646cf154 100644
--- a/src/demux/transmuxer.ts
+++ b/src/demux/transmuxer.ts
@@ -4,19 +4,19 @@ import { ErrorTypes, ErrorDetails } from '../errors';
 import Decrypter from '../crypt/decrypter';
 import AACDemuxer from '../demux/aacdemuxer';
 import MP4Demuxer from '../demux/mp4demuxer';
-import TSDemuxer from '../demux/tsdemuxer';
+import TSDemuxer, { TypeSupported } from '../demux/tsdemuxer';
 import MP3Demuxer from '../demux/mp3demuxer';
 import MP4Remuxer from '../remux/mp4-remuxer';
 import PassThroughRemuxer from '../remux/passthrough-remuxer';
-import type { Demuxer, KeyData } from '../types/demuxer';
-import type { Remuxer } from '../types/remuxer';
-import type { TransmuxerResult, ChunkMetadata } from '../types/transmuxer';
 import ChunkCache from './chunk-cache';
 import { appendUint8Array } from '../utils/mp4-tools';
-
 import { logger } from '../utils/logger';
+import type { Demuxer, KeyData } from '../types/demuxer';
+import type { Remuxer } from '../types/remuxer';
+import type { TransmuxerResult, ChunkMetadata } from '../types/transmuxer';
 import type { HlsConfig } from '../config';
-import { LevelKey } from '../loader/level-key';
+import type { LevelKey } from '../loader/level-key';
+import type { PlaylistLevelType } from '../types/loader';
 
 let now;
 // performance.now() not available on WebWorker, at least on Safari Desktop
@@ -47,9 +47,10 @@ muxConfig.forEach(({ demux }) => {
 
 export default class Transmuxer {
   private observer: HlsEventEmitter;
-  private typeSupported: any;
+  private typeSupported: TypeSupported;
   private config: HlsConfig;
-  private vendor: any;
+  private vendor: string;
+  private id: PlaylistLevelType;
   private demuxer?: Demuxer;
   private remuxer?: Remuxer;
   private decrypter?: Decrypter;
@@ -61,14 +62,16 @@ export default class Transmuxer {
 
   constructor(
     observer: HlsEventEmitter,
-    typeSupported,
+    typeSupported: TypeSupported,
     config: HlsConfig,
-    vendor
+    vendor: string,
+    id: PlaylistLevelType
   ) {
     this.observer = observer;
     this.typeSupported = typeSupported;
     this.config = config;
     this.vendor = vendor;
+    this.id = id;
   }
 
   configure(transmuxConfig: TransmuxConfig) {
@@ -258,7 +261,8 @@ export default class Transmuxer {
       textTrack,
       timeOffset,
       accurateTimeOffset,
-      true
+      true,
+      this.id
     );
     transmuxResults.push({
       remuxResult,
@@ -354,7 +358,8 @@ export default class Transmuxer {
       textTrack,
       timeOffset,
       accurateTimeOffset,
-      false
+      false,
+      this.id
     );
     return {
       remuxResult,
@@ -379,7 +384,8 @@ export default class Transmuxer {
           demuxResult.textTrack,
           timeOffset,
           accurateTimeOffset,
-          false
+          false,
+          this.id
         );
         return {
           remuxResult,
diff --git a/src/remux/mp4-remuxer.ts b/src/remux/mp4-remuxer.ts
index 3607d59a204..49b83dc17cc 100644
--- a/src/remux/mp4-remuxer.ts
+++ b/src/remux/mp4-remuxer.ts
@@ -12,6 +12,8 @@ import {
   RemuxedTrack,
   RemuxedUserdata,
 } from '../types/remuxer';
+import { PlaylistLevelType } from '../types/loader';
+import { toMsFromMpegTsClock } from '../utils/timescale-conversion';
 import type {
   AudioSample,
   AvcSample,
@@ -24,7 +26,6 @@ import type { TrackSet } from '../types/track';
 import type { SourceBufferName } from '../types/buffer';
 import type { Fragment } from '../loader/fragment';
 import type { HlsConfig } from '../config';
-import { toMsFromMpegTsClock } from '../utils/timescale-conversion';
 
 const MAX_SILENT_FRAME_DURATION = 10 * 1000; // 10 seconds
 const AAC_SAMPLES_PER_FRAME = 1024;
@@ -116,7 +117,8 @@ export default class MP4Remuxer implements Remuxer {
     textTrack: DemuxedUserdataTrack,
     timeOffset: number,
     accurateTimeOffset: boolean,
-    flush: boolean
+    flush: boolean,
+    playlistType: PlaylistLevelType
   ): RemuxerResult {
     let video: RemuxedTrack | undefined;
     let audio: RemuxedTrack | undefined;
@@ -202,7 +204,11 @@ export default class MP4Remuxer implements Remuxer {
             audioTimeOffset,
             this.isAudioContiguous,
             accurateTimeOffset,
-            enoughVideoSamples ? videoTimeOffset : undefined
+            hasVideo ||
+              enoughVideoSamples ||
+              playlistType === PlaylistLevelType.AUDIO
+              ? videoTimeOffset
+              : undefined
           );
           if (enoughVideoSamples) {
             const audioTrackLength = audio ? audio.endPTS - audio.startPTS : 0;
diff --git a/src/types/remuxer.ts b/src/types/remuxer.ts
index a8870a34530..0fbc89d080e 100644
--- a/src/types/remuxer.ts
+++ b/src/types/remuxer.ts
@@ -8,6 +8,7 @@ import {
   UserdataSample,
 } from './demuxer';
 import type { SourceBufferName } from './buffer';
+import type { PlaylistLevelType } from './loader';
 
 export interface Remuxer {
   remux(
@@ -17,7 +18,8 @@ export interface Remuxer {
     textTrack: DemuxedUserdataTrack,
     timeOffset: number,
     accurateTimeOffset: boolean,
-    flush: boolean
+    flush: boolean,
+    playlistType: PlaylistLevelType
   ): RemuxerResult;
   resetInitSegment(
     initSegment: Uint8Array | undefined,