Fix regression where subtitle options with AUTOSELECT and FORCED are …

…enabled at start (#6094)

* Do not enable subtitle options with AUTOSELECT=YES attribute
* Update and add initial selection tests for subtitle-controller
* Only pick forced subtitle option if it is the only one
Add default field to audio and subtitle selection options and forced field to subtitle selection option
* Address TextTrack change event overriding subtitle preference
Fix _TRACKS_UPDATED and _TRACK_SWITCH event order when preference is selected
* Do not auto select subtitle options with FORCED=YES attribute

api-extractor/report/hls.js.api.md

@@ -129,6 +129,7 @@ export type AudioSelectionOption = {
     name?: string;
     audioCodec?: string;
     groupId?: string;
+    default?: boolean;
 };
 
 // Warning: (ae-missing-release-tag) "AudioStreamController" is part of the package's API, but it is missing a release tag (@alpha, @beta, @public, or @internal)
@@ -3164,6 +3165,8 @@ export type SubtitleSelectionOption = {
     characteristics?: string;
     name?: string;
     groupId?: string;
+    default?: boolean;
+    forced?: boolean;
 };
 
 // Warning: (ae-missing-release-tag) "SubtitleStreamController" is part of the package's API, but it is missing a release tag (@alpha, @beta, @public, or @internal)

src/controller/audio-track-controller.ts

@@ -157,17 +157,31 @@ class AudioTrackController extends BasePlaylistController {
         // Do not dispatch AUDIO_TRACKS_UPDATED when there were and are no tracks
         return;
       }
+      this.tracksInGroup = audioTracks;
 
-      if (!currentTrack) {
-        currentTrack = this.setAudioOption(this.hls.config.audioPreference);
+      // Find preferred track
+      const audioPreference = this.hls.config.audioPreference;
+      if (!currentTrack && audioPreference) {
+        const groupIndex = findMatchingOption(
+          audioPreference,
+          audioTracks,
+          audioMatchPredicate,
+        );
+        if (groupIndex > -1) {
+          currentTrack = audioTracks[groupIndex];
+        } else {
+          const allIndex = findMatchingOption(audioPreference, this.tracks);
+          currentTrack = this.tracks[allIndex];
+        }
       }
 
-      this.tracksInGroup = audioTracks;
+      // Select initial track
       let trackId = this.findTrackId(currentTrack);
       if (trackId === -1 && currentTrack) {
         trackId = this.findTrackId(null);
       }
 
+      // Dispatch events and load track if needed
       const audioTracksUpdated: AudioTracksUpdatedData = { audioTracks };
       this.log(
         `Updating audio tracks, ${

src/controller/subtitle-track-controller.ts

@@ -35,7 +35,6 @@ class SubtitleTrackController extends BasePlaylistController {
   private currentTrack: MediaPlaylist | null = null;
   private selectDefaultTrack: boolean = true;
   private queuedDefaultTrack: number = -1;
-  private trackChangeListener: () => void = () => this.onTextTracksChanged();
   private asyncPollTrackChange: () => void = () => this.pollTrackChange(0);
   private useTextTrackPolling: boolean = false;
   private subtitlePollingInterval: number = -1;
@@ -51,7 +50,7 @@ class SubtitleTrackController extends BasePlaylistController {
     this.tracks.length = 0;
     this.tracksInGroup.length = 0;
     this.currentTrack = null;
-    this.trackChangeListener = this.asyncPollTrackChange = null as any;
+    this.onTextTracksChanged = this.asyncPollTrackChange = null as any;
     super.destroy();
   }
 
@@ -121,7 +120,7 @@ class SubtitleTrackController extends BasePlaylistController {
   private pollTrackChange(timeout: number) {
     self.clearInterval(this.subtitlePollingInterval);
     this.subtitlePollingInterval = self.setInterval(
-      this.trackChangeListener,
+      this.onTextTracksChanged,
       timeout,
     );
   }
@@ -231,12 +230,10 @@ class SubtitleTrackController extends BasePlaylistController {
           !subtitleGroups || subtitleGroups.indexOf(track.groupId) !== -1,
       );
       if (subtitleTracks.length) {
-        // Disable selectDefaultTrack if there are no default or forced tracks
+        // Disable selectDefaultTrack if there are no default tracks
         if (
           this.selectDefaultTrack &&
-          !subtitleTracks.some(
-            (track) => track.default || track.forced || track.autoselect,
-          )
+          !subtitleTracks.some((track) => track.default)
         ) {
           this.selectDefaultTrack = false;
         }
@@ -248,19 +245,31 @@ class SubtitleTrackController extends BasePlaylistController {
         // Do not dispatch SUBTITLE_TRACKS_UPDATED when there were and are no tracks
         return;
       }
+      this.tracksInGroup = subtitleTracks;
 
-      if (!currentTrack) {
-        currentTrack = this.setSubtitleOption(
-          this.hls.config.subtitlePreference,
+      // Find preferred track
+      const subtitlePreference = this.hls.config.subtitlePreference;
+      if (!currentTrack && subtitlePreference) {
+        this.selectDefaultTrack = false;
+        const groupIndex = findMatchingOption(
+          subtitlePreference,
+          subtitleTracks,
         );
+        if (groupIndex > -1) {
+          currentTrack = subtitleTracks[groupIndex];
+        } else {
+          const allIndex = findMatchingOption(subtitlePreference, this.tracks);
+          currentTrack = this.tracks[allIndex];
+        }
       }
 
-      this.tracksInGroup = subtitleTracks;
+      // Select initial track
       let trackId = this.findTrackId(currentTrack);
       if (trackId === -1 && currentTrack) {
         trackId = this.findTrackId(null);
       }
 
+      // Dispatch events and load track if needed
       const subtitleTracksUpdated: SubtitleTracksUpdatedData = {
         subtitleTracks,
       };
@@ -286,10 +295,7 @@ class SubtitleTrackController extends BasePlaylistController {
     for (let i = 0; i < tracks.length; i++) {
       const track = tracks[i];
       if (
-        (selectDefault &&
-          !track.default &&
-          !track.forced &&
-          !track.autoselect) ||
+        (selectDefault && !track.default) ||
         (!selectDefault && !currentTrack)
       ) {
         continue;
@@ -492,7 +498,7 @@ class SubtitleTrackController extends BasePlaylistController {
     }
 
     // exit if track id as already set or invalid
-    if (newId < -1 || newId >= tracks.length) {
+    if (newId < -1 || newId >= tracks.length || !Number.isFinite(newId)) {
       this.warn(`Invalid subtitle track id: ${newId}`);
       return;
     }
@@ -511,7 +517,7 @@ class SubtitleTrackController extends BasePlaylistController {
       this.hls.trigger(Events.SUBTITLE_TRACK_SWITCH, { id: newId });
       return;
     }
-    const trackLoaded = track.details && !track.details.live;
+    const trackLoaded = !!track.details && !track.details.live;
     if (newId === this.trackId && track === lastTrack && trackLoaded) {
       return;
     }
@@ -533,7 +539,7 @@ class SubtitleTrackController extends BasePlaylistController {
     this.loadPlaylist(hlsUrlParameters);
   }
 
-  private onTextTracksChanged(): void {
+  private onTextTracksChanged = () => {
     if (!this.useTextTrackPolling) {
       self.clearInterval(this.subtitlePollingInterval);
     }
@@ -559,7 +565,7 @@ class SubtitleTrackController extends BasePlaylistController {
     if (this.subtitleTrack !== trackId) {
       this.setSubtitleTrack(trackId);
     }
-  }
+  };
 }
 
 export default SubtitleTrackController;

src/types/media-playlist.ts

@@ -23,6 +23,7 @@ export type AudioSelectionOption = {
   name?: string;
   audioCodec?: string;
   groupId?: string;
+  default?: boolean;
 };
 
 export type SubtitleSelectionOption = {
@@ -31,6 +32,8 @@ export type SubtitleSelectionOption = {
   characteristics?: string;
   name?: string;
   groupId?: string;
+  default?: boolean;
+  forced?: boolean;
 };
 
 // audioTracks, captions and subtitles returned by `M3U8Parser.parseMasterPlaylistMedia`

src/utils/rendition-helper.ts

@@ -323,12 +323,22 @@ export function matchesOption(
     track: MediaPlaylist,
   ) => boolean,
 ): boolean {
-  const { groupId, name, lang, assocLang, characteristics } = option;
+  const {
+    groupId,
+    name,
+    lang,
+    assocLang,
+    characteristics,
+    default: isDefault,
+  } = option;
+  const forced = (option as SubtitleSelectionOption).forced;
   return (
     (groupId === undefined || track.groupId === groupId) &&
     (name === undefined || track.name === name) &&
     (lang === undefined || track.lang === lang) &&
     (lang === undefined || track.assocLang === assocLang) &&
+    (isDefault === undefined || track.default === isDefault) &&
+    (forced === undefined || track.forced === forced) &&
     (characteristics === undefined ||
       characteristicsMatch(characteristics, track.characteristics)) &&
     (matchPredicate === undefined || matchPredicate(option, track))