fix(HLS): Fix audio detection when there is no audio data but it appears in PMT (#7838)

Author: avelad

lib/media/segment_utils.js

@@ -64,24 +64,34 @@ shaka.media.SegmentUtils = class {
       switch (tsCodecs.audio) {
         case 'aac':
         case 'aac-loas':
-          codecs.push('mp4a.40.2');
-          hasAudio = true;
+          if (tsParser.getAudioData().length) {
+            codecs.push('mp4a.40.2');
+            hasAudio = true;
+          }
           break;
         case 'mp3':
-          codecs.push('mp4a.40.34');
-          hasAudio = true;
+          if (tsParser.getAudioData().length) {
+            codecs.push('mp4a.40.34');
+            hasAudio = true;
+          }
           break;
         case 'ac3':
-          codecs.push('ac-3');
-          hasAudio = true;
+          if (tsParser.getAudioData().length) {
+            codecs.push('ac-3');
+            hasAudio = true;
+          }
           break;
         case 'ec3':
-          codecs.push('ec-3');
-          hasAudio = true;
+          if (tsParser.getAudioData().length) {
+            codecs.push('ec-3');
+            hasAudio = true;
+          }
           break;
         case 'opus':
-          codecs.push('opus');
-          hasAudio = true;
+          if (tsParser.getAudioData().length) {
+            codecs.push('opus');
+            hasAudio = true;
+          }
           break;
       }
     }