From 246f7c5684c79b62ef61e956b6231c8b8b664e87 Mon Sep 17 00:00:00 2001
From: Bidisha Das <officialbidisha1@gmail.com>
Date: Thu, 20 Jul 2023 03:00:20 +0530
Subject: [PATCH] fix(HLS): Add subtitle role when there are no roles (#5357)

Fixes #5355

Co-authored-by: Joey Parrish <joeyparrish@users.noreply.github.com>
---
 lib/hls/hls_parser.js       | 18 +++++++++-
 test/hls/hls_parser_unit.js | 69 +++++++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+), 1 deletion(-)

diff --git a/lib/hls/hls_parser.js b/lib/hls/hls_parser.js
index e50c459271..85bf68fadf 100644
--- a/lib/hls/hls_parser.js
+++ b/lib/hls/hls_parser.js
@@ -2436,6 +2436,22 @@ shaka.hls.HlsParser = class {
     // stream is lazy-loaded.
     const mimeType = this.guessMimeTypeBeforeLoading_(type, codecs) ||
         this.guessMimeTypeFallback_(type);
+    const roles = [];
+    if (characteristics) {
+      for (const characteristic of characteristics.split(',')) {
+        roles.push(characteristic);
+      }
+    }
+
+    const kind = (type == shaka.util.ManifestParserUtils.ContentType.TEXT) ?
+        shaka.util.ManifestParserUtils.TextStreamKind.SUBTITLE : undefined;
+
+    // If there are no roles, and we have defaulted to the subtitle "kind" for
+    // this track, add the implied subtitle role.
+    if (!roles.length &&
+        kind === shaka.util.ManifestParserUtils.TextStreamKind.SUBTITLE) {
+      roles.push(shaka.util.ManifestParserUtils.TextStreamKind.SUBTITLE);
+    }
 
     return {
       id: this.globalId_++,
@@ -2462,7 +2478,7 @@ shaka.hls.HlsParser = class {
       width: undefined,
       height: undefined,
       bandwidth: undefined,
-      roles: characteristics ? characteristics.split(',') : [],
+      roles,
       forced,
       channelsCount,
       audioSamplingRate: sampleRate,
diff --git a/test/hls/hls_parser_unit.js b/test/hls/hls_parser_unit.js
index 2e95381ca6..c987e99347 100644
--- a/test/hls/hls_parser_unit.js
+++ b/test/hls/hls_parser_unit.js
@@ -1173,6 +1173,75 @@ describe('HlsParser', () => {
     await testHlsParser(master, media, manifest);
   });
 
+  it('adds subtitle role when characteristics are empty', async () => {
+    const master = [
+      '#EXTM3U\n',
+      '#EXT-X-STREAM-INF:BANDWIDTH=200,CODECS="avc1",',
+      'RESOLUTION=960x540,FRAME-RATE=60,AUDIO="aud1",SUBTITLES="sub1"\n',
+      'video\n',
+
+      '#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="aud1",LANGUAGE="en",',
+      'NAME="English",URI="audio"\n',
+
+      '#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="aud1",LANGUAGE="en",',
+      'CHARACTERISTICS="public.accessibility.describes-video,',
+      'public.accessibility.describes-music-and-sound",',
+      'NAME="English (describes-video)",URI="audio2"\n',
+
+      '#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="sub1",LANGUAGE="en",',
+      'NAME="English (subtitle)",DEFAULT=YES,AUTOSELECT=YES,',
+      'URI="text"\n',
+
+      '#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="sub1",LANGUAGE="en",',
+      'NAME="English (caption)",DEFAULT=YES,AUTOSELECT=YES,',
+      'CHARACTERISTICS="public.accessibility.describes-music-and-sound",',
+      'URI="text2"\n',
+    ].join('');
+    const manifest = shaka.test.ManifestGenerator.generate((manifest) => {
+      manifest.anyTimeline();
+      manifest.addPartialVariant((variant) => {
+        variant.language = 'en';
+        variant.addPartialStream(ContentType.VIDEO);
+        variant.addPartialStream(ContentType.AUDIO, (stream) => {
+          stream.language = 'en';
+          stream.roles = [];
+        });
+      });
+      manifest.addPartialVariant((variant) => {
+        variant.language = 'en';
+        variant.addPartialStream(ContentType.VIDEO);
+        variant.addPartialStream(ContentType.AUDIO, (stream) => {
+          stream.language = 'en';
+          stream.roles = [
+            'public.accessibility.describes-video',
+            'public.accessibility.describes-music-and-sound',
+          ];
+        });
+      });
+      manifest.addPartialTextStream((stream) => {
+        stream.language = 'en';
+        stream.kind = TextStreamKind.SUBTITLE;
+        stream.roles = [
+          'subtitle',
+        ];
+      });
+      manifest.addPartialTextStream((stream) => {
+        stream.language = 'en';
+        stream.kind = TextStreamKind.SUBTITLE;
+        stream.roles = [
+          'public.accessibility.describes-music-and-sound',
+        ];
+      });
+      manifest.sequenceMode = sequenceMode;
+      manifest.type = shaka.media.ManifestParser.HLS;
+    });
+
+    fakeNetEngine.setResponseText('test:/master', master);
+
+    const actual = await parser.start('test:/master', playerInterface);
+    expect(actual).toEqual(manifest);
+  });
+
   it('parses characteristics from text tags', async () => {
     const master = [
       '#EXTM3U\n',