feat(dash): Add support for mpegB:cicp:ChannelConfiguration (shaka-pr…

…oject#3057) Closes: shaka-project#2873
NoriginMedia · Dec 23, 2020 · 607deb7 · 607deb7
1 parent e68ac92
commit 607deb7
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diff --git a/lib/dash/dash_parser.js b/lib/dash/dash_parser.js
@@ -1357,6 +1357,26 @@ shaka.dash.DashParser = class {
           return numBits;
         }
 
+        // Defined by https://dashif.org/identifiers/audio_source_metadata/ and clause 8.2, in ISO/IEC 23001-8.
+        case 'urn:mpeg:mpegB:cicp:ChannelConfiguration': {
+          const noValue = 0;
+          const channelCountMapping = [
+            noValue, 1, 2, 3, 4, 5, 6, 8, 2, 3, /* 0--9 */
+            4, 7, 8, 24, 8, 12, 10, 12, 14, 12, /* 10--19 */
+            14, /* 20 */
+          ];
+          const intValue = parseInt(value, 10);
+          if (!intValue) {  // 0 or NaN
+            shaka.log.warning('Channel parsing failure! ' +
+                          'Ignoring scheme and value', scheme, value);
+            continue;
+          }
+          if (intValue > noValue && intValue < channelCountMapping.length) {
+            return channelCountMapping[intValue];
+          }
+          continue;
+        }
+
         default:
           shaka.log.warning(
               'Unrecognized audio channel scheme:', scheme, value);

diff --git a/test/dash/dash_parser_manifest_unit.js b/test/dash/dash_parser_manifest_unit.js
@@ -1366,6 +1366,24 @@ describe('DashParser Manifest', () => {
           {'urn:dolby:dash:audio_channel_configuration:2011': 'x'});
     });
 
+    it('parses MPEG channel configuration scheme', async () => {
+      // Parses a simple channel count.
+      await testAudioChannelConfiguration(2,
+          {'urn:mpeg:mpegB:cicp:ChannelConfiguration': '2'});
+
+      // Parses a high channel count.
+      await testAudioChannelConfiguration(24,
+          {'urn:mpeg:mpegB:cicp:ChannelConfiguration': '13'});
+
+      // Results in null if the value is not an integer.
+      await testAudioChannelConfiguration(null,
+          {'urn:mpeg:mpegB:cicp:ChannelConfiguration': 'foo'});
+
+      // Results in null if the value is not in a spec range.
+      await testAudioChannelConfiguration(null,
+          {'urn:mpeg:mpegB:cicp:ChannelConfiguration': '100'});
+    });
+
     it('ignores unrecognized schemes', async () => {
       await testAudioChannelConfiguration(null, {'foo': 'bar'});