feat: Allow playback of HLS Media Playlist with AAC by default (shaka…

…-project#4564)

Closes shaka-project#4561

lib/hls/hls_parser.js

@@ -597,7 +597,16 @@ shaka.hls.HlsParser = class {
       // Get necessary info for this stream, from the config. These are things
       // we would normally find from the master playlist (e.g. from values on
       // EXT-X-MEDIA tags).
-      const fullMimeType = this.config_.hls.mediaPlaylistFullMimeType;
+      let fullMimeType = this.config_.hls.mediaPlaylistFullMimeType;
+      // Try to infer the full mimetype better.
+      if (playlist.segments.length) {
+        const parsedUri = new goog.Uri(playlist.segments[0].absoluteUri);
+        const extension = parsedUri.getPath().split('.').pop();
+        if (extension === 'aac') {
+          fullMimeType = 'audio/aac';
+        }
+      }
+
       const mimeType = shaka.util.MimeUtils.getBasicType(fullMimeType);
       const type = mimeType.split('/')[0];
       const codecs = shaka.util.MimeUtils.getCodecs(fullMimeType);

test/hls/hls_parser_unit.js

@@ -3871,6 +3871,32 @@ describe('HlsParser', () => {
     await testHlsParser(media, '', manifest);
   });
 
+  it('honors hls.mediaPlaylistFullMimeType but detects AAC', async () => {
+    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.aac',
+    ].join('');
+
+    const config = shaka.util.PlayerConfiguration.createDefault().manifest;
+    parser.configure(config);
+
+    const manifest = shaka.test.ManifestGenerator.generate((manifest) => {
+      manifest.sequenceMode = true;
+      manifest.anyTimeline();
+      manifest.addPartialVariant((variant) => {
+        variant.addPartialStream(ContentType.AUDIO, (stream) => {
+          stream.mime('audio/aac');
+        });
+      });
+    });
+
+    await testHlsParser(media, '', manifest);
+  });
+
   it('syncs on sequence with ignoreManifestProgramDateTime', async () => {
     const config = shaka.util.PlayerConfiguration.createDefault().manifest;
     config.hls.ignoreManifestProgramDateTime = true;