feat(DASH): MPD Alternate support

externs/shaka/ads.js

@@ -250,6 +250,13 @@ shaka.extern.IAdManager = class extends EventTarget {
    */
   onHLSInterstitialMetadata(basePlayer, baseVideo, interstitial) {}
 
+  /**
+   * @param {!shaka.Player} basePlayer
+   * @param {!HTMLMediaElement} baseVideo
+   * @param {shaka.extern.TimelineRegionInfo} region
+   */
+  onDASHInterstitialMetadata(basePlayer, baseVideo, region) {}
+
   /**
    * @param {shaka.extern.AdInterstitial} interstitial
    */

karma.conf.js

@@ -260,6 +260,7 @@ module.exports = (config) => {
       {pattern: 'test/test/assets/6339/*', included: false},
       {pattern: 'test/test/assets/dash-aes-128/*', included: false},
       {pattern: 'test/test/assets/dash-clearkey/*', included: false},
+      {pattern: 'test/test/assets/dash-mpd-alternate/*', included: false},
       {pattern: 'test/test/assets/dash-vr/*', included: false},
       {pattern: 'test/test/assets/dv-p8-hevc/*', included: false},
       {pattern: 'test/test/assets/dv-p10-av1/*', included: false},

lib/ads/ad_manager.js

@@ -832,6 +832,22 @@ shaka.ads.AdManager = class extends shaka.util.FakeEventTarget {
     }
   }
 
+  /**
+   * @override
+   * @export
+   */
+  onDASHInterstitialMetadata(basePlayer, baseVideo, region) {
+    if (region.schemeIdUri != 'urn:mpeg:dash:event:alternativeMPD:2022') {
+      return;
+    }
+    if (!this.interstitialAdManager_) {
+      this.initInterstitial(/* adContainer= */ null, basePlayer, baseVideo);
+    }
+    if (this.interstitialAdManager_) {
+      this.interstitialAdManager_.addRegion(region);
+    }
+  }
+
   /**
    * @override
    * @export

lib/ads/interstitial_ad_manager.js

@@ -225,6 +225,51 @@ shaka.ads.InterstitialAdManager = class {
     }
   }
 
+  /**
+   * @param {shaka.extern.TimelineRegionInfo} region
+   */
+  addRegion(region) {
+    let alternativeMPDUri;
+    let alternativeMPDmode;
+    for (const node of region.eventNode.children) {
+      if (node.tagName == 'AlternativeMPD') {
+        const uri = node.attributes['uri'];
+        const mode = node.attributes['mode'];
+        if (uri) {
+          alternativeMPDUri = uri;
+          alternativeMPDmode = mode;
+          break;
+        }
+      }
+    }
+    if (!alternativeMPDUri) {
+      shaka.log.alwaysWarn('Unsupported MPD alternate', region);
+      return;
+    }
+    const isReplace = alternativeMPDmode == 'replace';
+    const isInsert = alternativeMPDmode == 'insert';
+    if (!isReplace && !isInsert) {
+      shaka.log.warning('Unsupported MPD alternate', region);
+      return;
+    }
+    const interstitial = {
+      id: null,
+      startTime: region.startTime,
+      endTime: isReplace ? region.endTime : null,
+      uri: alternativeMPDUri,
+      isSkippable: false,
+      skipOffset: null,
+      canJump: true,
+      resumeOffset: isInsert ? 0 : null,
+      playoutLimit: null,
+      once: false,
+      pre: false,
+      post: false,
+      timelineRange: isReplace && !isInsert,
+    };
+    this.addInterstitials([interstitial]);
+  }
+
   /**
    * @param {string} url
    * @return {!Promise}

lib/player.js

@@ -2156,6 +2156,9 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
       preloadManager.addQueuedOperation(false, () => {
         if (this.adManager_) {
           this.adManager_.onDashTimedMetadata(region);
+          goog.asserts.assert(this.video_, 'Must have video');
+          this.adManager_.onDASHInterstitialMetadata(
+              this, this.video_, region);
         }
       });
     });

test/ads_integration.js

@@ -367,4 +367,31 @@ describe('Ads', () => {
       await player.unload();
     });
   });
+
+  describe('support MPD Alternate', () => {
+    /** @type {string} */
+    const streamUri = '/base/test/test/assets/dash-mpd-alternate/dash.mpd';
+
+    it('without support for multiple media elements', async () => {
+      player.configure('ads.supportsMultipleMediaElements', false);
+
+      adManager.initInterstitial(adContainer, player, video);
+
+      await player.load(streamUri);
+      await video.play();
+      expect(player.isLive()).toBe(false);
+
+      // Wait a maximum of 10 seconds before the ad starts playing.
+      await waiter.timeoutAfter(10)
+          .waitForEvent(adManager, shaka.ads.Utils.AD_STARTED);
+      await waiter.timeoutAfter(20)
+          .waitForEvent(adManager, shaka.ads.Utils.AD_STOPPED);
+
+      // Play for 5 seconds, but stop early if the video ends.  If it takes
+      // longer than 30 seconds, fail the test.
+      await waiter.waitUntilPlayheadReachesOrFailOnTimeout(video, 5, 30);
+
+      await player.unload();
+    });
+  });
 });

test/test/assets/dash-mpd-alternate/dash.mpd

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+Version information:
+Axinom.MediaProcessing v3.0.0 targeting General Purpose Media Format specification v7
+ffmpeg version N-81423-g61fac0e Copyright (c) 2000-2016 the FFmpeg developers
+x265 [info]: HEVC encoder version 2.0+12-49a0d1176aef5bc6
+x264 0.148.2705 3f5ed56
+MP4Box - GPAC version 0.6.2-DEV-rev683-g7b29fbe-master
+MediaInfoLib - v0.7.87
+
+For more info about this video, see https://github.com/Axinom/dash-test-vectors
+-->
+<MPD xmlns="urn:mpeg:dash:schema:mpd:2011" type="static" mediaPresentationDuration="PT0H12M14.000S" maxSegmentDuration="PT0H0M4.000S" profiles="urn:mpeg:dash:profile:isoff-live:2011,http://dashif.org/guidelines/dash264" >
+  <Period duration="PT0H00M04.000S">
+    <AdaptationSet segmentAlignment="true" group="1" maxWidth="1920" maxHeight="1080" maxFrameRate="24" par="16:9" lang="und">
+      <SegmentTemplate timescale="24" media="$Number%04d$.m4s" startNumber="1" duration="96" initialization="init.mp4" />
+      <Representation id="1" mimeType="video/mp4" codecs="avc1.64001f" width="512" height="288" frameRate="24" sar="1:1" startWithSAP="1" bandwidth="389802"></Representation>
+    </AdaptationSet>
+  </Period>
+  <Period duration="PT0H00M16.000S">
+    <EventStream schemeIdUri="urn:mpeg:dash:event:alternativeMPD:2022" timescale="10000000">
+      <Event presentationTime="0" duration="40000000" id="1">
+        <AlternativeMPD uri="/base/test/test/assets/dash-aes-128/dash.mpd" mode="replace" />
+      </Event>
+    </EventStream>
+    <AdaptationSet segmentAlignment="true" group="1" maxWidth="1920" maxHeight="1080" maxFrameRate="24" par="16:9" lang="und">
+      <SegmentTemplate timescale="24" media="$Number%04d$.m4s" startNumber="1" duration="96" initialization="init.mp4" />
+      <Representation id="1" mimeType="video/mp4" codecs="avc1.64001f" width="512" height="288" frameRate="24" sar="1:1" startWithSAP="1" bandwidth="389802"></Representation>
+    </AdaptationSet>
+  </Period>
+</MPD>

test/test/util/fake_ad_manager.js

@@ -94,6 +94,9 @@ shaka.test.FakeAdManager = class extends shaka.util.FakeEventTarget {
   /** @override */
   onHLSInterstitialMetadata(basePlayer, baseVideo, interstitial) {}
 
+  /** @override */
+  onDASHInterstitialMetadata(basePlayer, baseVideo, region) {}
+
   /** @override */
   addCustomInterstitial(interstitial) {}