feat(DASH): Add signalling the last segment number in Period (#6416)

Closes #2430 Test stream: http://dash.akamaized.net/dash264/TestCasesIOP41/LastSegmentNumber/1/manifest_last_segment_num.mpd
shaka-project · Apr 9, 2024 · 07a3241 · 07a3241
1 parent bca6252
commit 07a3241
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Showing 3 changed files with 46 additions and 8 deletions.
diff --git a/lib/dash/dash_parser.js b/lib/dash/dash_parser.js
@@ -1153,11 +1153,15 @@ shaka.dash.DashParser = class {
       }
     }
 
+    let lastSegmentNumber = null;
+
     const supplementalProperties =
         TXml.findChildren(elem, 'SupplementalProperty');
     for (const prop of supplementalProperties) {
       const schemeId = prop.attributes['schemeIdUri'];
-      if (schemeId == transferCharacteristicsScheme) {
+      if (schemeId == 'http://dashif.org/guidelines/last-segment-number') {
+        lastSegmentNumber = parseInt(prop.attributes['value'], 10) - 1;
+      } else if (schemeId == transferCharacteristicsScheme) {
         videoRange = getVideoRangeFromTransferCharacteristicCICP(
             parseInt(prop.attributes['value'], 10),
         );
@@ -1303,7 +1307,8 @@ shaka.dash.DashParser = class {
     const streams = representations.map((representation) => {
       const parsedRepresentation = this.parseRepresentation_(context,
           contentProtection, kind, language, label, main, roleValues,
-          closedCaptions, representation, accessibilityPurpose);
+          closedCaptions, representation, accessibilityPurpose,
+          lastSegmentNumber);
       if (parsedRepresentation) {
         parsedRepresentation.hdr = parsedRepresentation.hdr || videoRange;
         parsedRepresentation.fastSwitching = isFastSwitching;
@@ -1388,13 +1393,15 @@ shaka.dash.DashParser = class {
    * @param {!shaka.extern.xml.Node} node
    * @param {?shaka.media.ManifestParser.AccessibilityPurpose}
    *   accessibilityPurpose
+   * @param {?number} lastSegmentNumber
    *
    * @return {?shaka.extern.Stream} The Stream, or null when there is a
    *   non-critical parsing error.
    * @private
    */
   parseRepresentation_(context, contentProtection, kind, language, label,
-      isPrimary, roles, closedCaptions, node, accessibilityPurpose) {
+      isPrimary, roles, closedCaptions, node, accessibilityPurpose,
+      lastSegmentNumber) {
     const TXml = shaka.util.TXml;
     const ContentType = shaka.util.ManifestParserUtils.ContentType;
 
@@ -1483,7 +1490,7 @@ shaka.dash.DashParser = class {
         streamInfo = shaka.dash.SegmentTemplate.createStreamInfo(
             context, requestSegment, this.streamMap_, hasManifest,
             this.config_.dash.initialSegmentLimit, this.periodDurations_,
-            aesKey);
+            aesKey, lastSegmentNumber);
       } else {
         goog.asserts.assert(isText,
             'Must have Segment* with non-text streams.');

diff --git a/lib/dash/segment_template.js b/lib/dash/segment_template.js
@@ -38,11 +38,12 @@ shaka.dash.SegmentTemplate = class {
    *   a SegmentTemplate with fixed duration.
    * @param {!Object.<string, number>} periodDurationMap
    * @param {shaka.extern.aesKey|undefined} aesKey
+   * @param {?number} lastSegmentNumber
    * @return {shaka.dash.DashParser.StreamInfo}
    */
   static createStreamInfo(
       context, requestSegment, streamMap, isUpdate, segmentLimit,
-      periodDurationMap, aesKey) {
+      periodDurationMap, aesKey, lastSegmentNumber) {
     goog.asserts.assert(context.representation.segmentTemplate,
         'Should only be called with SegmentTemplate');
     const SegmentTemplate = shaka.dash.SegmentTemplate;
@@ -85,7 +86,7 @@ shaka.dash.SegmentTemplate = class {
         generateSegmentIndex: () => {
           return SegmentTemplate.generateSegmentIndexFromDuration_(
               shallowCopyOfContext, info, segmentLimit, initSegmentReference,
-              periodDurationMap, aesKey);
+              periodDurationMap, aesKey, lastSegmentNumber);
         },
       };
     } else {
@@ -307,12 +308,13 @@ shaka.dash.SegmentTemplate = class {
    * @param {shaka.media.InitSegmentReference} initSegmentReference
    * @param {!Object.<string, number>} periodDurationMap
    * @param {shaka.extern.aesKey|undefined} aesKey
+   * @param {?number} lastSegmentNumber
    * @return {!Promise.<shaka.media.SegmentIndex>}
    * @private
    */
   static generateSegmentIndexFromDuration_(
       context, info, segmentLimit, initSegmentReference, periodDurationMap,
-      aesKey) {
+      aesKey, lastSegmentNumber) {
     goog.asserts.assert(info.mediaTemplate,
         'There should be a media template with duration');
 
@@ -408,7 +410,7 @@ shaka.dash.SegmentTemplate = class {
     const minPosition = context.dynamic ?
         Math.max(range[0], range[1] - segmentLimit + 1) :
         range[0];
-    const maxPosition = range[1];
+    const maxPosition = lastSegmentNumber || range[1];
 
     const references = [];
     const createReference = (position) => {

diff --git a/test/dash/dash_parser_manifest_unit.js b/test/dash/dash_parser_manifest_unit.js
@@ -2279,6 +2279,35 @@ describe('DashParser Manifest', () => {
     }
   });
 
+  it('signaling last segment number via SupplementalProperty', async () => {
+    // (DASH-IF IOP v4.3 4.4.3.6.)
+    const scheme = 'http://dashif.org/guidelines/last-segment-number';
+    const value = 368;
+    const manifestText = [
+      '<MPD minBufferTime="PT75S" type="static">',
+      '  <Period id="1" duration="PT0H12M14.167S">',
+      '    <AdaptationSet id="2">',
+      `      <SupplementalProperty schemeIdUri="${scheme}" value="${value}" />`,
+      '      <Representation codecs="avc1.640028" mimeType="video/mp4">',
+      '        <SegmentTemplate startNumber="1" media="m-$Number$.mp4"',
+      '          initialization="i.mp4" timescale="12288" duration="24576"/>',
+      '      </Representation>',
+      '    </AdaptationSet>',
+      '  </Period>',
+      '</MPD>',
+    ].join('\n');
+
+    fakeNetEngine.setResponseText('dummy://foo', manifestText);
+
+    /** @type {shaka.extern.Manifest} */
+    const manifest = await parser.start('dummy://foo', playerInterface);
+    expect(manifest.variants.length).toBe(1);
+    const stream = manifest.variants[0].video;
+    await stream.createSegmentIndex();
+    goog.asserts.assert(stream.segmentIndex, 'Null segmentIndex!');
+    expect(Array.from(stream.segmentIndex).length).toBe(367);
+  });
+
   it('Does not error when image adaptation sets are present', async () => {
     const manifestText = [
       '<MPD minBufferTime="PT75S">',