feat(DASH): Add MPD Chaining support (#6641)

Close #3926

README.md

@@ -106,6 +106,7 @@ DASH features supported:
  - WebVTT and TTML
  - CEA-608/708 captions
  - Multi-codec variants (on platforms with changeType support)
+ - MPD chaining
 
 DASH features **not** supported:
  - Xlink with actuate=onRequest

demo/common/assets.js

@@ -170,6 +170,9 @@ shakaAssets.Feature = {
 
   // Set if the asset is VR.
   VR: 'VR',
+
+  // Set if the asset has MPD Chaining.
+  MPD_CHAINING: 'MPD Chaining',
 };
 
 
@@ -303,6 +306,20 @@ shakaAssets.testAssets = [
       .addFeature(shakaAssets.Feature.SUBTITLES)
       .addFeature(shakaAssets.Feature.WEBM)
       .addFeature(shakaAssets.Feature.OFFLINE),
+  new ShakaDemoAssetInfo(
+      /* name= */ 'Angel One (multicodec, multilingual, mpd chaining)',
+      /* iconUri= */ 'https://storage.googleapis.com/shaka-asset-icons/angel_one.png',
+      /* manifestUri= */ 'https://storage.googleapis.com/shaka-demo-assets/angel-one/dash_chaining.mpd',
+      /* source= */ shakaAssets.Source.SHAKA)
+      .addDescription('A clip from a classic Star Trek TNG episode, presented in MPEG-DASH.')
+      .markAsFeatured('Angel One')
+      .addFeature(shakaAssets.Feature.DASH)
+      .addFeature(shakaAssets.Feature.MP4)
+      .addFeature(shakaAssets.Feature.MULTIPLE_LANGUAGES)
+      .addFeature(shakaAssets.Feature.SUBTITLES)
+      .addFeature(shakaAssets.Feature.WEBM)
+      .addFeature(shakaAssets.Feature.OFFLINE)
+      .addFeature(shakaAssets.Feature.MPD_CHAINING),
   new ShakaDemoAssetInfo(
       /* name= */ 'Angel One (multicodec, multilingual, Widevine)',
       /* iconUri= */ 'https://storage.googleapis.com/shaka-asset-icons/angel_one.png',
@@ -994,6 +1011,15 @@ shakaAssets.testAssets = [
       .addFeature(shakaAssets.Feature.MP4)
       .addFeature(shakaAssets.Feature.LIVE)
       .addFeature(shakaAssets.Feature.THUMBNAILS),
+  new ShakaDemoAssetInfo(
+      /* name= */ 'DASH-IF - Regular chaining, Live',
+      /* iconUri= */ '',
+      /* manifestUri= */ 'https://dash.akamaized.net/dash264/TestCasesIOP33/MPDChaining/regular_chain/1/manifest_regular_MPDChaining_live.mpd',
+      /* source= */ shakaAssets.Source.DASH_IF)
+      .addFeature(shakaAssets.Feature.DASH)
+      .addFeature(shakaAssets.Feature.MP4)
+      .addFeature(shakaAssets.Feature.LIVE)
+      .addFeature(shakaAssets.Feature.MPD_CHAINING),
   // End DASH-IF Assets }}}
 
   // bitcodin assets {{{

demo/config.js

@@ -564,7 +564,11 @@ shakaDemo.Config = class {
         .addBoolInput_('Use native HLS on Safari (Clear)',
             'streaming.useNativeHlsOnSafari')
         .addBoolInput_('Use native HLS for FairPlay',
-            'streaming.useNativeHlsForFairPlay');
+            'streaming.useNativeHlsForFairPlay')
+        .addNumberInput_('Time window at end to preload next URL',
+            'streaming.preloadNextUrlWindow',
+            /* canBeDecimal= */ true,
+            /* canBeZero= */ true);
     this.addRetrySection_('streaming', 'Streaming Retry Parameters');
   }
 

demo/search.js

@@ -399,6 +399,8 @@ shakaDemo.Search = class {
         'Filters for assets that use Content Steering.');
     this.makeBooleanInput_(specialContainer, Feature.VR, FEATURE,
         'Filters for assets that are VR.');
+    this.makeBooleanInput_(specialContainer, Feature.MPD_CHAINING, FEATURE,
+        'Filters for assets that have MPD Chaining');
 
     container.appendChild(this.resultsDiv_);
   }

externs/shaka/manifest.js

@@ -21,7 +21,8 @@
  *   sequenceMode: boolean,
  *   ignoreManifestTimestampsInSegmentsMode: boolean,
  *   type: string,
- *   serviceDescription: ?shaka.extern.ServiceDescription
+ *   serviceDescription: ?shaka.extern.ServiceDescription,
+ *   nextUrl: ?string
  * }}
  *
  * @description
@@ -93,6 +94,8 @@
  * @property {?shaka.extern.ServiceDescription} serviceDescription
  *   The service description for the manifest. Used to adapt playbackRate to
  *   decrease latency.
+ * @property {?string} nextUrl
+ *   The next url to play.
  *
  * @exportDoc
  */

externs/shaka/player.js

@@ -1252,7 +1252,8 @@ shaka.extern.ManifestConfiguration;
  *   vodDynamicPlaybackRate: boolean,
  *   vodDynamicPlaybackRateLowBufferRate: number,
  *   vodDynamicPlaybackRateBufferRatio: number,
- *   infiniteLiveStreamDuration: boolean
+ *   infiniteLiveStreamDuration: boolean,
+ *   preloadNextUrlWindow: number
  * }}
  *
  * @description
@@ -1442,6 +1443,12 @@ shaka.extern.ManifestConfiguration;
  *   If <code>true</code>, the media source live duration
  *   set as a<code>Infinity</code>
  *   Defaults to <code> false </code>.
+ * @property {number} preloadNextUrlWindow
+ *   The window of time at the end of the presentation to begin preloading the
+ *   next URL, such as one specified by a urn:mpeg:dash:chaining:2016 element
+ *   in DASH. Measured in seconds. If the value is 0, the next URL will not
+ *   be preloaded at all.
+ *   Defaults to <code> 30 </code>.
  * @exportDoc
  */
 shaka.extern.StreamingConfiguration;

lib/dash/dash_parser.js

@@ -697,6 +697,7 @@ shaka.dash.DashParser = class {
         ignoreManifestTimestampsInSegmentsMode: false,
         type: shaka.media.ManifestParser.DASH,
         serviceDescription: this.parseServiceDescription_(mpd),
+        nextUrl: this.parseMpdChaining_(mpd),
       };
 
       // We only need to do clock sync when we're using presentation start
@@ -782,6 +783,32 @@ shaka.dash.DashParser = class {
     return null;
   }
 
+  /**
+   * Reads chaining url.
+   *
+   * @param {!shaka.extern.xml.Node} mpd
+   * @return {?string}
+   * @private
+   */
+  parseMpdChaining_(mpd) {
+    const TXml = shaka.util.TXml;
+    const supplementalProperties =
+        TXml.findChildren(mpd, 'SupplementalProperty');
+
+    if (!supplementalProperties.length) {
+      return null;
+    }
+
+    for (const prop of supplementalProperties) {
+      const schemeId = prop.attributes['schemeIdUri'];
+      if (schemeId == 'urn:mpeg:dash:chaining:2016') {
+        return prop.attributes['value'];
+      }
+    }
+
+    return null;
+  }
+
   /**
    * Reads and parses the periods from the manifest.  This first does some
    * partial parsing so the start and duration is available when parsing

lib/hls/hls_parser.js

@@ -880,6 +880,7 @@ shaka.hls.HlsParser = class {
         this.config_.hls.ignoreManifestTimestampsInSegmentsMode,
       type: shaka.media.ManifestParser.HLS,
       serviceDescription: null,
+      nextUrl: null,
     };
 
     // If there is no 'CODECS' attribute in the manifest and codec guessing is

lib/mss/mss_parser.js

@@ -419,6 +419,7 @@ shaka.mss.MssParser = class {
         ignoreManifestTimestampsInSegmentsMode: false,
         type: shaka.media.ManifestParser.MSS,
         serviceDescription: null,
+        nextUrl: null,
       };
 
       // This is the first point where we have a meaningful presentation start

lib/offline/manifest_converter.js

@@ -93,6 +93,7 @@ shaka.offline.ManifestConverter = class {
       ignoreManifestTimestampsInSegmentsMode: false,
       type: manifestDB.type || shaka.media.ManifestParser.UNKNOWN,
       serviceDescription: null,
+      nextUrl: null,
     };
   }
 

lib/player.js

@@ -779,6 +779,9 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
     this.checkVariantsTimer_ =
         new shaka.util.Timer(() => this.checkVariants_());
 
+    /** @private {?shaka.media.PreloadManager} */
+    this.preloadNextUrl_ = null;
+
     // Even though |attach| will start in later interpreter cycles, it should be
     // the LAST thing we do in the constructor because conceptually it relies on
     // player having been initialized.
@@ -1337,6 +1340,14 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
         this.drmEngine_ = null;
       }
 
+      if (this.preloadNextUrl_ &&
+          this.assetUri_ != this.preloadNextUrl_.getAssetUri()) {
+        if (!this.preloadNextUrl_.isDestroyed()) {
+          this.preloadNextUrl_.destroy();
+        }
+        this.preloadNextUrl_ = null;
+      }
+
       this.assetUri_ = null;
       this.mimeType_ = null;
       this.bufferObserver_ = null;
@@ -1431,6 +1442,9 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
     }
 
     if (this.assetUri_) {
+      // Note: This is used to avoid the destruction of the nextUrl
+      // preloadManager that can be the current one.
+      this.assetUri_ = assetUri;
       await this.unload(/* initializeMediaSource= */ false);
     }
 
@@ -1632,6 +1646,7 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
         // properly destroyed or released.
         await preloadManager.destroy();
       }
+      this.preloadNextUrl_ = null;
     }
   }
 
@@ -2406,6 +2421,28 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
       this.loadEventManager_.listen(
           mediaElement, 'timeupdate', onVideoProgress);
       this.onVideoProgress_();
+      if (this.manifest_.nextUrl) {
+        if (this.config_.streaming.preloadNextUrlWindow > 0) {
+          const onTimeUpdate = async () => {
+            const timeToEnd = this.video_.duration - this.video_.currentTime;
+            if (!isNaN(timeToEnd)) {
+              if (timeToEnd <= this.config_.streaming.preloadNextUrlWindow) {
+                this.loadEventManager_.unlisten(
+                    mediaElement, 'timeupdate', onTimeUpdate);
+                goog.asserts.assert(this.manifest_.nextUrl,
+                    'this.manifest_.nextUrl should be valid.');
+                this.preloadNextUrl_ =
+                    await this.preload(this.manifest_.nextUrl);
+              }
+            }
+          };
+          this.loadEventManager_.listen(
+              mediaElement, 'timeupdate', onTimeUpdate);
+        }
+        this.loadEventManager_.listen(mediaElement, 'ended', () => {
+          this.load(this.preloadNextUrl_ || this.manifest_.nextUrl);
+        });
+      }
     }
 
     if (this.adManager_) {

lib/util/player_configuration.js

@@ -249,6 +249,7 @@ shaka.util.PlayerConfiguration = class {
       vodDynamicPlaybackRateLowBufferRate: 0.95,
       vodDynamicPlaybackRateBufferRatio: 0.5,
       infiniteLiveStreamDuration: false,
+      preloadNextUrlWindow: 30,
     };
 
     // WebOS, Tizen, Chromecast and Hisense have long hardware pipelines

roadmap.md

@@ -23,6 +23,8 @@ v5.0 - 2024 Q4
 v4.9 - 2024 Q3
  - DASH patch manifests
    https://github.com/shaka-project/shaka-player/issues/2228
+ - DASH: MPD chaining
+   https://github.com/shaka-project/shaka-player/issues/3926
 
 =====
 

test/dash/dash_parser_manifest_unit.js

@@ -2630,6 +2630,23 @@ describe('DashParser Manifest', () => {
     });
   });
 
+  it('parses urn:mpeg:dash:chaining:2016', async () => {
+    const source = [
+      '<MPD minBufferTime="PT75S" type="dynamic"',
+      '     availabilityStartTime="1970-01-01T00:00:00Z">',
+      '  <SupplementalProperty schemeIdUri="urn:mpeg:dash:chaining:2016"',
+      '    value="https://nextUrl" />',
+      '</MPD>',
+    ].join('\n');
+
+    fakeNetEngine.setResponseText('dummy://foo', source);
+
+    /** @type {shaka.extern.Manifest} */
+    const manifest = await parser.start('dummy://foo', playerInterface);
+
+    expect(manifest.nextUrl).toBe('https://nextUrl');
+  });
+
   it('parses urn:mpeg:dash:ssr:2023', async () => { // eslint-disable-line max-len
     const manifestText = [
       '<MPD minBufferTime="PT75S">',

test/media/playhead_unit.js

@@ -137,6 +137,7 @@ describe('Playhead', () => {
       ignoreManifestTimestampsInSegmentsMode: false,
       type: 'UNKNOWN',
       serviceDescription: null,
+      nextUrl: null,
     };
 
     config = shaka.util.PlayerConfiguration.createDefault().streaming;

test/media/streaming_engine_integration.js

@@ -601,6 +601,7 @@ describe('StreamingEngine', () => {
         ignoreManifestTimestampsInSegmentsMode: false,
         type: 'UNKNOWN',
         serviceDescription: null,
+        nextUrl: null,
         variants: [{
           id: 1,
           video: {

test/player_integration.js

@@ -1416,6 +1416,32 @@ describe('Player', () => {
     await waiter.waitUntilPlayheadReachesOrFailOnTimeout(video, 1, 10);
   });
 
+  describe('supports nextUrl', () => {
+    const urlWithNextUrl = 'test:sintel_next_url_compiled';
+
+    it('with preload', async () => {
+      player.configure('streaming.preloadNextUrlWindow', 30);
+      await player.load(urlWithNextUrl);
+      await video.play();
+      await waiter.timeoutAfter(30).waitForEnd(video);
+      expect(player.getAssetUri()).toBe(urlWithNextUrl);
+      // Delay needed to load the next URL.
+      await shaka.test.Util.delay(1);
+      expect(player.getAssetUri()).not.toBe(urlWithNextUrl);
+    });
+
+    it('without preload', async () => {
+      player.configure('streaming.preloadNextUrlWindow', 0);
+      await player.load(urlWithNextUrl);
+      await video.play();
+      await waiter.timeoutAfter(30).waitForEnd(video);
+      expect(player.getAssetUri()).toBe(urlWithNextUrl);
+      // Delay needed to load the next URL.
+      await shaka.test.Util.delay(1);
+      expect(player.getAssetUri()).not.toBe(urlWithNextUrl);
+    });
+  });
+
   describe('buffer gap', () => {
     // Regression test for issue #6339.
     it('skip initial buffer gap', async () => {

test/test/util/manifest_generator.js

@@ -103,6 +103,8 @@ shaka.test.ManifestGenerator.Manifest = class {
     this.type = 'UNKNOWN';
     /** @type {?shaka.extern.ServiceDescription} */
     this.serviceDescription = null;
+    /** @type {?string} */
+    this.nextUrl = null;
 
 
     /** @type {shaka.extern.Manifest} */

test/test/util/streaming_engine_util.js

@@ -320,6 +320,7 @@ shaka.test.StreamingEngineUtil = class {
       ignoreManifestTimestampsInSegmentsMode: false,
       type: 'UNKNOWN',
       serviceDescription: null,
+      nextUrl: null,
     };
 
     /** @type {shaka.extern.Variant} */

test/test/util/test_scheme.js

@@ -53,7 +53,8 @@ let ExtraMetadataType;
  *   licenseServers: (!Object.<string, string>|undefined),
  *   licenseRequestHeaders: (!Object.<string, string>|undefined),
  *   customizeStream: (function(shaka.test.ManifestGenerator.Stream)|undefined),
- *   sequenceMode: (boolean|undefined)
+ *   sequenceMode: (boolean|undefined),
+ *   nextUrl: (string|undefined)
  * }}
  */
 let MetadataType;
@@ -289,6 +290,9 @@ shaka.test.TestScheme = class {
       const manifest = shaka.test.ManifestGenerator.generate((manifest) => {
         manifest.presentationTimeline.setDuration(data.duration);
         manifest.sequenceMode = data.sequenceMode || false;
+        if (data.nextUrl) {
+          manifest.nextUrl = data.nextUrl + suffix;
+        }
 
         const videoResolutions = data.videoResolutions || [undefined];
         const audioLanguages = data.audioLanguages ||
@@ -588,6 +592,13 @@ shaka.test.TestScheme.DATA = {
     duration: 30,
   },
 
+  'sintel_next_url': {
+    video: sintelVideoSegment,
+    audio: sintelAudioSegment,
+    duration: 5,
+    nextUrl: 'test:sintel',
+  },
+
   // https://github.com/shaka-project/shaka-player/issues/2553
   'forced_subs_simulation': {
     audio: sintelAudioSegment,