fix(DASH): Always fit segments to period boundaries on VOD (#8825)

Fixes #8774

Author: tykus160

lib/dash/segment_template.js

@@ -134,6 +134,7 @@ shaka.dash.SegmentTemplate = class {
       if (!segmentIndex) {
         shaka.log.debug(`Creating TSI with end ${periodEnd}`);
         segmentIndex = new TimelineSegmentIndex(
+            context.dynamic,
             info,
             context.representation.originalId,
             context.bandwidth,
@@ -148,7 +149,8 @@ shaka.dash.SegmentTemplate = class {
       } else {
         const tsi = /** @type {!TimelineSegmentIndex} */(segmentIndex);
         tsi.appendTemplateInfo(
-            info, periodStart, periodEnd, initSegmentReference);
+            info, periodStart, periodEnd, initSegmentReference,
+            context.dynamic);
 
         const availabilityStart =
           context.presentationTimeline.getSegmentAvailabilityStart();
@@ -178,7 +180,7 @@ shaka.dash.SegmentTemplate = class {
           if (segmentIndex instanceof shaka.dash.TimelineSegmentIndex &&
               segmentIndex.isEmpty()) {
             segmentIndex.appendTemplateInfo(info, periodStart,
-                periodEnd, initSegmentReference);
+                periodEnd, initSegmentReference, context.dynamic);
           }
           return Promise.resolve(segmentIndex);
         },
@@ -723,7 +725,7 @@ shaka.dash.SegmentTemplate = class {
  */
 shaka.dash.TimelineSegmentIndex = class extends shaka.media.SegmentIndex {
   /**
-   *
+   * @param {boolean} dynamic
    * @param {!shaka.dash.SegmentTemplate.SegmentTemplateInfo} templateInfo
    * @param {?string} representationId
    * @param {number} bandwidth
@@ -735,11 +737,14 @@ shaka.dash.TimelineSegmentIndex = class extends shaka.media.SegmentIndex {
    * @param {shaka.extern.aesKey|undefined} aesKey
    * @param {number} segmentSequenceCadence
    */
-  constructor(templateInfo, representationId, bandwidth, getBaseUris,
+  constructor(dynamic, templateInfo, representationId, bandwidth, getBaseUris,
       urlParams, periodStart, periodEnd, initSegmentReference,
       aesKey, segmentSequenceCadence) {
     super([]);
 
+    /** @private {boolean} */
+    this.dynamic_ = dynamic;
+
     /** @private {?shaka.dash.SegmentTemplate.SegmentTemplateInfo} */
     this.templateInfo_ = templateInfo;
 
@@ -839,9 +844,12 @@ shaka.dash.TimelineSegmentIndex = class extends shaka.media.SegmentIndex {
    * @param {number} periodStart
    * @param {number} periodEnd
    * @param {shaka.media.InitSegmentReference} initSegmentReference
+   * @param {boolean} dynamic
    */
-  appendTemplateInfo(info, periodStart, periodEnd, initSegmentReference) {
+  appendTemplateInfo(info, periodStart, periodEnd, initSegmentReference,
+      dynamic) {
     this.updateInitSegmentReference(initSegmentReference);
+    this.dynamic_ = dynamic;
     if (!this.templateInfo_) {
       this.templateInfo_ = info;
       this.periodStart_ = periodStart;
@@ -1033,7 +1041,7 @@ shaka.dash.TimelineSegmentIndex = class extends shaka.media.SegmentIndex {
       if (correctedPosition === this.getNumReferences() - 1 &&
           this.periodEnd_ !== Infinity) {
         // See https://github.com/shaka-project/shaka-player/issues/8672
-        if (Math.abs(segmentEnd - this.periodEnd_) > 0.1) {
+        if (this.dynamic_ && Math.abs(segmentEnd - this.periodEnd_) > 0.1) {
           segmentEnd = Math.min(segmentEnd, this.periodEnd_);
         } else {
           segmentEnd = this.periodEnd_;