fix(HLS): Fix external subtitles out of sync in HLS (#5491)

Fixes #5458
Fixes #5443

Backported to v4.2.x

externs/shaka/manifest.js

@@ -321,7 +321,8 @@ shaka.extern.FetchCryptoKeysFunction;
  *   tilesLayout: (string|undefined),
  *   matchedStreams:
  *      (!Array.<shaka.extern.Stream>|!Array.<shaka.extern.StreamDB>|
- *      undefined)
+ *      undefined),
+ *   external: boolean
  * }}
  *
  * @description
@@ -434,6 +435,9 @@ shaka.extern.FetchCryptoKeysFunction;
  * @property {(!Array.<shaka.extern.Stream>|!Array.<shaka.extern.StreamDB>|
  *   undefined)} matchedStreams
  *   The streams in all periods which match the stream. Used for Dash.
+ * @property {boolean} external
+ *   Indicate if the stream was added externally.
+ *   Eg: external text tracks.
  *
  * @exportDoc
  */

externs/shaka/offline.js

@@ -132,7 +132,8 @@ shaka.extern.ManifestDB;
  *   audioSamplingRate: ?number,
  *   spatialAudio: boolean,
  *   closedCaptions: Map.<string, string>,
- *   tilesLayout: (string|undefined)
+ *   tilesLayout: (string|undefined),
+ *   external: boolean
  * }}
  *
  * @property {number} id
@@ -193,6 +194,9 @@ shaka.extern.ManifestDB;
  *   The value is a grid-item-dimension consisting of two positive decimal
  *   integers in the format: column-x-row ('4x3'). It describes the arrangement
  *   of Images in a Grid. The minimum valid LAYOUT is '1x1'.
+ * @property {boolean} external
+ *   Indicate if the stream was added externally.
+ *   Eg: external text tracks.
  */
 shaka.extern.StreamDB;
 

lib/dash/dash_parser.js

@@ -1337,6 +1337,7 @@ shaka.dash.DashParser = class {
         hdr,
         tilesLayout,
         matchedStreams: [],
+        external: false,
       };
     }
 

lib/hls/hls_parser.js

@@ -1757,6 +1757,7 @@ shaka.hls.HlsParser = class {
       closedCaptions,
       hdr: undefined,
       tilesLayout: undefined,
+      external: false,
     };
 
     return {

lib/media/media_source_engine.js

@@ -354,7 +354,7 @@ shaka.media.MediaSourceEngine = class {
       let mimeType = shaka.util.MimeUtils.getFullType(
           stream.mimeType, stream.codecs);
       if (contentType == ContentType.TEXT) {
-        this.reinitText(mimeType, sequenceMode);
+        this.reinitText(mimeType, sequenceMode, stream.external);
       } else {
         if ((forceTransmuxTS || !MediaSource.isTypeSupported(mimeType)) &&
             shaka.media.Transmuxer.isSupported(mimeType, contentType)) {
@@ -383,13 +383,14 @@ shaka.media.MediaSourceEngine = class {
    * Reinitialize the TextEngine for a new text type.
    * @param {string} mimeType
    * @param {boolean} sequenceMode
+   * @param {boolean} external
    */
-  reinitText(mimeType, sequenceMode) {
+  reinitText(mimeType, sequenceMode, external) {
     if (!this.textEngine_) {
       this.textEngine_ = new shaka.text.TextEngine(this.textDisplayer_);
     }
     this.textEngine_.initParser(mimeType, sequenceMode,
-        this.segmentRelativeVttTiming_);
+        external || this.segmentRelativeVttTiming_);
   }
 
   /**
@@ -564,7 +565,7 @@ shaka.media.MediaSourceEngine = class {
       // the video stream, so textEngine may not have been initialized.
       if (!this.textEngine_) {
         this.reinitText(shaka.util.MimeUtils.CEA608_CLOSED_CAPTION_MIMETYPE,
-            this.sequenceMode_);
+            this.sequenceMode_, /* external= */ false);
       }
 
       if (transmuxedData.metadata) {
@@ -593,7 +594,7 @@ shaka.media.MediaSourceEngine = class {
     } else if (hasClosedCaptions) {
       if (!this.textEngine_) {
         this.reinitText(shaka.util.MimeUtils.CEA608_CLOSED_CAPTION_MIMETYPE,
-            this.sequenceMode_);
+            this.sequenceMode_, /* external= */ false);
       }
       // If it is the init segment for closed captions, initialize the closed
       // caption parser.

lib/media/streaming_engine.js

@@ -240,7 +240,7 @@ shaka.media.StreamingEngine = class {
     const mimeType = shaka.util.MimeUtils.getFullType(
         stream.mimeType, stream.codecs);
     this.playerInterface_.mediaSourceEngine.reinitText(
-        mimeType, this.manifest_.sequenceMode);
+        mimeType, this.manifest_.sequenceMode, stream.external);
 
     const textDisplayer =
         this.playerInterface_.mediaSourceEngine.getTextDisplayer();
@@ -447,7 +447,7 @@ shaka.media.StreamingEngine = class {
       const fullMimeType = shaka.util.MimeUtils.getFullType(
           stream.mimeType, stream.codecs);
       this.playerInterface_.mediaSourceEngine.reinitText(
-          fullMimeType, this.manifest_.sequenceMode);
+          fullMimeType, this.manifest_.sequenceMode, stream.external);
     }
 
     // Releases the segmentIndex of the old stream.

lib/offline/indexeddb/v1_storage_cell.js

@@ -176,6 +176,7 @@ shaka.offline.indexeddb.V1StorageCell = class
       spatialAudio: false,
       closedCaptions: null,
       tilesLayout: undefined,
+      external: false,
     };
   }
 

lib/offline/indexeddb/v2_storage_cell.js

@@ -125,6 +125,7 @@ shaka.offline.indexeddb.V2StorageCell = class
       spatialAudio: false,
       closedCaptions: null,
       tilesLayout: undefined,
+      external: false,
     };
   }
 

lib/offline/manifest_converter.js

@@ -202,6 +202,7 @@ shaka.offline.ManifestConverter = class {
       spatialAudio: streamDB.spatialAudio,
       closedCaptions: streamDB.closedCaptions,
       tilesLayout: streamDB.tilesLayout,
+      external: streamDB.external,
     };
 
     return stream;

lib/offline/storage.js

@@ -1324,6 +1324,7 @@ shaka.offline.Storage = class {
       spatialAudio: stream.spatialAudio,
       closedCaptions: stream.closedCaptions,
       tilesLayout: stream.tilesLayout,
+      external: stream.external,
     };
 
     const startTime =

lib/player.js

@@ -2233,6 +2233,7 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
         audioSamplingRate: null,
         spatialAudio: false,
         closedCaptions: null,
+        external: false,
       },
       bandwidth: 100,
       allowedByApplication: true,
@@ -4627,6 +4628,7 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
       audioSamplingRate: null,
       spatialAudio: false,
       closedCaptions: null,
+      external: true,
     };
 
     const fullMimeType = shaka.util.MimeUtils.getFullType(
@@ -5057,6 +5059,7 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
               audioSamplingRate: null,
               spatialAudio: false,
               closedCaptions: null,
+              external: false,
             };
             manifest.textStreams.push(textStream);
             closedCaptionsSet.add(id);

lib/util/periods.js

@@ -1491,6 +1491,7 @@ shaka.util.PeriodCombiner = class {
       audioSamplingRate: null,
       spatialAudio: false,
       closedCaptions: null,
+      external: false,
     };
   }
 
@@ -1527,6 +1528,7 @@ shaka.util.PeriodCombiner = class {
       audioSamplingRate: null,
       spatialAudio: false,
       closedCaptions: null,
+      external: false,
     };
   }
 

test/media/adaptation_set_unit.js

@@ -218,6 +218,7 @@ describe('AdaptationSet', () => {
       forced: false,
       trickModeVideo: null,
       type: '',
+      external: false,
     };
   }
 });

test/media/media_source_engine_unit.js

@@ -1258,7 +1258,7 @@ describe('MediaSourceEngine', () => {
     });
 
     it('destroys text engines', async () => {
-      mediaSourceEngine.reinitText('text/vtt', false);
+      mediaSourceEngine.reinitText('text/vtt', false, false);
 
       await mediaSourceEngine.destroy();
       expect(mockTextEngine).toBeTruthy();

test/offline/manifest_convert_unit.js

@@ -316,6 +316,7 @@ describe('ManifestConverter', () => {
       audioSamplingRate: null,
       spatialAudio: false,
       closedCaptions: null,
+      external: false,
     };
 
     return streamDB;
@@ -389,6 +390,7 @@ describe('ManifestConverter', () => {
       spatialAudio: false,
       closedCaptions: null,
       tilesLayout: undefined,
+      external: false,
     };
   }
 
@@ -438,6 +440,7 @@ describe('ManifestConverter', () => {
       spatialAudio: false,
       closedCaptions: null,
       tilesLayout: undefined,
+      external: false,
     };
   }
 
@@ -486,6 +489,7 @@ describe('ManifestConverter', () => {
       spatialAudio: false,
       closedCaptions: null,
       tilesLayout: undefined,
+      external: false,
     };
   }
 
@@ -531,6 +535,7 @@ describe('ManifestConverter', () => {
       spatialAudio: streamDb.spatialAudio,
       closedCaptions: streamDb.closedCaptions,
       tilesLayout: streamDb.tilesLayout,
+      external: streamDb.external,
     };
 
     expect(stream).toEqual(expectedStream);

test/test/util/manifest_generator.js

@@ -544,6 +544,8 @@ shaka.test.ManifestGenerator.Stream = class {
       this.hdr = undefined;
       /** @type {(string|undefined)} */
       this.tilesLayout = undefined;
+      /** @type {boolean} */
+      this.external = false;
     }
 
     /** @type {shaka.extern.Stream} */

test/test/util/offline_utils.js

@@ -56,6 +56,7 @@ shaka.test.OfflineUtils = class {
       audioSamplingRate: null,
       spatialAudio: false,
       closedCaptions: null,
+      external: false,
     };
   }
 

test/test/util/streaming_engine_util.js

@@ -410,6 +410,7 @@ shaka.test.StreamingEngineUtil = class {
       roles: [],
       forced: false,
       spatialAudio: false,
+      external: false,
     };
   }
 
@@ -447,6 +448,7 @@ shaka.test.StreamingEngineUtil = class {
       roles: [],
       forced: false,
       spatialAudio: false,
+      external: false,
     };
   }
 
@@ -482,6 +484,7 @@ shaka.test.StreamingEngineUtil = class {
       roles: [],
       forced: false,
       spatialAudio: false,
+      external: false,
     };
   }
 };