From 0761bd753e74a0ecb3e8ef1ef7bcaf8d482a503a Mon Sep 17 00:00:00 2001
From: Alvaro Velad <alvaro.velad@mirada.tv>
Date: Tue, 28 Apr 2020 09:22:26 +0200
Subject: [PATCH] Parse HLS CHARACTERISTICS attribute

---
 lib/hls/hls_parser.js       | 16 ++++++++++----
 test/hls/hls_parser_unit.js | 43 +++++++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 4 deletions(-)

diff --git a/lib/hls/hls_parser.js b/lib/hls/hls_parser.js
index 50c85f3fed..7eb9bed52c 100644
--- a/lib/hls/hls_parser.js
+++ b/lib/hls/hls_parser.js
@@ -1046,12 +1046,13 @@ shaka.hls.HlsParser = class {
     const autoselectAttr = tag.getAttribute('AUTOSELECT');
     const primary = !!defaultAttr || !!autoselectAttr;
     const channelsCount = type == 'audio' ? this.getChannelsCount_(tag) : null;
+    const characteristics = tag.getAttributeValue('CHARACTERISTICS');
     // TODO: Should we take into account some of the currently ignored
     // attributes: FORCED, INSTREAM-ID, CHARACTERISTICS? Attribute
     // descriptions: https://bit.ly/2lpjOhj
     const streamInfo = await this.createStreamInfo_(
         verbatimMediaPlaylistUri, codecs, type, language, primary, name,
-        channelsCount, /* closedCaptions= */ null);
+        channelsCount, /* closedCaptions= */ null, characteristics);
     if (this.groupIdToStreamInfosMap_.has(groupId)) {
       this.groupIdToStreamInfosMap_.get(groupId).push(streamInfo);
     } else {
@@ -1093,7 +1094,8 @@ shaka.hls.HlsParser = class {
     const codecs = this.guessCodecs_(type, allCodecs);
     const streamInfo = await this.createStreamInfo_(verbatimMediaPlaylistUri,
         codecs, type, /* language= */ 'und', /* primary= */ false,
-        /* name= */ null, /* channelcount= */ null, closedCaptions);
+        /* name= */ null, /* channelcount= */ null, closedCaptions,
+        /* characteristics= */ null);
     if (streamInfo == null) {
       return null;
     }
@@ -1117,11 +1119,12 @@ shaka.hls.HlsParser = class {
    * @param {?string} name
    * @param {?number} channelsCount
    * @param {Map.<string, string>} closedCaptions
+   * @param {?string} characteristics
    * @return {!Promise.<?shaka.hls.HlsParser.StreamInfo>}
    * @private
    */
   async createStreamInfo_(verbatimMediaPlaylistUri, codecs, type, language,
-      primary, name, channelsCount, closedCaptions) {
+      primary, name, channelsCount, closedCaptions, characteristics) {
     // TODO: Refactor, too many parameters
     let absoluteMediaPlaylistUri = shaka.hls.Utils.constructAbsoluteUri(
         this.masterPlaylistUri_, verbatimMediaPlaylistUri);
@@ -1244,6 +1247,11 @@ shaka.hls.HlsParser = class {
     const kind = (type == shaka.util.ManifestParserUtils.ContentType.TEXT) ?
         shaka.util.ManifestParserUtils.TextStreamKind.SUBTITLE : undefined;
 
+    const roles = [];
+    if (characteristics) {
+      roles.push(characteristics);
+    }
+
     /** @type {shaka.extern.Stream} */
     const stream = {
       id: this.globalId_++,
@@ -1268,7 +1276,7 @@ shaka.hls.HlsParser = class {
       width: undefined,
       height: undefined,
       bandwidth: undefined,
-      roles: [],
+      roles: roles,
       channelsCount,
       audioSamplingRate: null,
       closedCaptions,
diff --git a/test/hls/hls_parser_unit.js b/test/hls/hls_parser_unit.js
index 768fa8ec37..58bcaae302 100644
--- a/test/hls/hls_parser_unit.js
+++ b/test/hls/hls_parser_unit.js
@@ -770,6 +770,49 @@ describe('HlsParser', () => {
     await testHlsParser(master, media, manifest);
   });
 
+  it('parses characteristics from audio tags', async () => {
+    const master = [
+      '#EXTM3U\n',
+      '#EXT-X-STREAM-INF:BANDWIDTH=200,CODECS="avc1,mp4a",',
+      'RESOLUTION=960x540,FRAME-RATE=60,AUDIO="aud1"\n',
+      'video\n',
+      '#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="aud1",LANGUAGE="en",',
+      'URI="audio"\n',
+      '#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="aud1",LANGUAGE="en",',
+      'CHARACTERISTICS="public.accessibility.describes-video",URI="audio2"\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 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';
+        });
+      });
+      manifest.addPartialVariant((variant) => {
+        variant.language = 'en';
+        variant.addPartialStream(ContentType.VIDEO);
+        variant.addPartialStream(ContentType.AUDIO, (stream) => {
+          stream.language = 'en';
+          stream.roles = ['public.accessibility.describes-video'];
+        });
+      });
+    });
+
+    await testHlsParser(master, media, manifest);
+  });
+
   it('should call filter during parsing', async () => {
     const master = [
       '#EXTM3U\n',