fix(HLS): Recognize CEA subtitles when CLOSED-CAPTIONS attribute is m…

…issing (#5916) Fixes #5915
shaka-project · Nov 22, 2023 · 58d4597 · 58d4597
1 parent c898364
commit 58d4597
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Showing 2 changed files with 49 additions and 3 deletions.
diff --git a/lib/hls/hls_parser.js b/lib/hls/hls_parser.js
@@ -1672,9 +1672,15 @@ shaka.hls.HlsParser = class {
     // the value NONE. If the value is a quoted-string, it MUST match the
     // value of the GROUP-ID attribute of an EXT-X-MEDIA tag elsewhere in the
     // Playlist whose TYPE attribute is CLOSED-CAPTIONS.
-    if (type == ContentType.VIDEO && closedCaptionsAttr &&
-    closedCaptionsAttr != 'NONE') {
-      return this.groupIdToClosedCaptionsMap_.get(closedCaptionsAttr);
+    if (type == ContentType.VIDEO) {
+      if (closedCaptionsAttr && closedCaptionsAttr != 'NONE') {
+        return this.groupIdToClosedCaptionsMap_.get(closedCaptionsAttr);
+      } else if (!closedCaptionsAttr &&
+          this.groupIdToClosedCaptionsMap_.size) {
+        for (const key of this.groupIdToClosedCaptionsMap_.keys()) {
+          return this.groupIdToClosedCaptionsMap_.get(key);
+        }
+      }
     }
     return null;
   }

diff --git a/test/hls/hls_parser_unit.js b/test/hls/hls_parser_unit.js
@@ -750,6 +750,46 @@ describe('HlsParser', () => {
     await testHlsParser(master, media, manifest);
   });
 
+  it('parses audio+video variant with global closed captions', async () => {
+    const master = [
+      '#EXTM3U\n',
+      '#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="aud1",LANGUAGE="eng",CHANNELS="2",',
+      'URI="audio"\n',
+      '#EXT-X-MEDIA:TYPE=CLOSED-CAPTIONS,GROUP-ID="cap1",LANGUAGE="eng",',
+      'INSTREAM-ID="CC1"\n',
+      '#EXT-X-STREAM-INF:BANDWIDTH=200,CODECS="avc1,mp4a",',
+      'RESOLUTION=960x540,FRAME-RATE=60,AUDIO="aud1"\n',
+      'video\n',
+    ].join('');
+
+    const media = [
+      '#EXTM3U\n',
+      '#EXT-X-PLAYLIST-TYPE:VOD\n',
+      '#EXT-X-MAP:URI="init.mp4",BYTERANGE="616@0"\n',
+      '#EXTINF:5,\n',
+      '#EXT-X-BYTERANGE:121090@616\n',
+      'main.mp4',
+    ].join('');
+
+    const closedCaptions = new Map([['CC1', 'en']]);
+    const manifest = shaka.test.ManifestGenerator.generate((manifest) => {
+      manifest.anyTimeline();
+      manifest.addPartialVariant((variant) => {
+        variant.addPartialStream(ContentType.VIDEO, (stream) => {
+          stream.closedCaptions = closedCaptions;
+          stream.mime('video/mp4', 'avc1');
+        });
+        variant.addPartialStream(ContentType.AUDIO, (stream) => {
+          stream.mime('audio/mp4', 'mp4a');
+        });
+      });
+      manifest.sequenceMode = sequenceMode;
+      manifest.type = shaka.media.ManifestParser.HLS;
+    });
+
+    await testHlsParser(master, media, manifest);
+  });
+
   it('parses audio+video variant with no closed captions', async () => {
     const master = [
       '#EXTM3U\n',