fix(DASH): decrease memory preasure on manifest with SegmentReference…

… by updating old initSegmentReference (shaka-project#6499)

Helps on shaka-project#6070

Backported to v4.7.x

AUTHORS

@@ -28,6 +28,7 @@ Bonnier Broadcasting <*@bonnierbroadcasting.com>
 Bryan Huh <[email protected]>
 Charter Communications Inc <*@charter.com>
 Code It <*@code-it.fr>
+Cristian Atehortua <[email protected]>
 Damien Deis <[email protected]>
 Dany L'Hébreux <[email protected]>
 Dave Nicholas <[email protected]>

CONTRIBUTORS

@@ -44,6 +44,7 @@ Casey Occhialini <[email protected]>
 Chad Assareh <[email protected]>
 Chris Fillmore <[email protected]>
 Costel Madalin Grecu <[email protected]>
+Cristian Atehortua <[email protected]>
 Damien Deis <[email protected]>
 Dany L'Hébreux <[email protected]>
 Dave Nicholas <[email protected]>

lib/dash/segment_template.js

@@ -694,7 +694,7 @@ shaka.dash.TimelineSegmentIndex = class extends shaka.media.SegmentIndex {
    */
   appendTemplateInfo(info, periodStart, periodEnd, shouldFit,
       initSegmentReference) {
-    this.initSegmentReference_ = initSegmentReference;
+    this.updateInitSegmentReference(initSegmentReference);
     if (!this.templateInfo_) {
       this.templateInfo_ = info;
       this.periodStart_ = periodStart;
@@ -725,6 +725,24 @@ shaka.dash.TimelineSegmentIndex = class extends shaka.media.SegmentIndex {
     }
   }
 
+  /**
+   * Updates the init segment reference and propagates the update to all
+   * references.
+   * @param {shaka.media.InitSegmentReference} initSegmentReference
+   */
+  updateInitSegmentReference(initSegmentReference) {
+    if (this.initSegmentReference_ === initSegmentReference) {
+      return;
+    }
+
+    this.initSegmentReference_ = initSegmentReference;
+    for (const reference of this.references) {
+      if (reference) {
+        reference.updateInitSegmentReference(initSegmentReference);
+      }
+    }
+  }
+
   /**
    *
    * @param {number} time

lib/media/segment_reference.js

@@ -586,6 +586,18 @@ shaka.media.SegmentReference = class {
       this.offset(offset);
     }
   }
+
+  /**
+   * Updates the init segment reference and propagates the update to all partial
+   * references.
+   * @param {shaka.media.InitSegmentReference} initSegmentReference
+   */
+  updateInitSegmentReference(initSegmentReference) {
+    this.initSegmentReference = initSegmentReference;
+    for (const partialReference of this.partialReferences) {
+      partialReference.updateInitSegmentReference(initSegmentReference);
+    }
+  }
 };