Improve live stream support

* Support minimumUpdatePeriod="PT0S".
* Fix comparisons with very large timestamps.
* Assign default Period ID if not given.
* Increase suggestedPresentationDelay.

Closes #331
Closes #339

Change-Id: I091cb7ab3e2a1cdb38e4161fe139a96a10de3807

lib/dash/dash_parser.js

@@ -104,7 +104,7 @@ shaka.dash.DashParser.MIN_UPDATE_PERIOD_ = 3;
  * @private
  * @const {number}
  */
-shaka.dash.DashParser.DEFAULT_SUGGESTED_PRESENTATION_DELAY_ = 2;
+shaka.dash.DashParser.DEFAULT_SUGGESTED_PRESENTATION_DELAY_ = 5;
 
 
 /**
@@ -301,7 +301,8 @@ shaka.dash.DashParser.prototype.start =
   this.filterPeriod_ = filterPeriod;
   this.onError_ = onError;
   return this.requestManifest_().then(function() {
-    this.setUpdateTimer_(0);
+    if (this.networkingEngine_)
+      this.setUpdateTimer_(0);
     return this.manifest_;
   }.bind(this));
 };
@@ -413,9 +414,8 @@ shaka.dash.DashParser.prototype.parseManifest_ =
 
   var minBufferTime =
       XmlUtils.parseAttr(mpd, 'minBufferTime', XmlUtils.parseDuration);
-  this.updatePeriod_ =
-      XmlUtils.parseAttr(mpd, 'minimumUpdatePeriod', XmlUtils.parseDuration) ||
-      0;
+  this.updatePeriod_ = /** @type {number} */ (XmlUtils.parseAttr(
+      mpd, 'minimumUpdatePeriod', XmlUtils.parseDuration, -1));
 
   var presentationStartTime = XmlUtils.parseAttr(
       mpd, 'availabilityStartTime', XmlUtils.parseDate);
@@ -593,6 +593,14 @@ shaka.dash.DashParser.prototype.parsePeriod_ = function(
   context.period = this.createFrame_(periodInfo.node, null, baseUris);
   context.periodInfo = periodInfo;
 
+  // If the period doesn't have an ID, give it one based on its start time.
+  if (!context.period.id) {
+    shaka.log.info(
+        'No Period ID given for Period with start time ' + periodInfo.start +
+        ',  Assigning a default');
+    context.period.id = '__shaka_period_' + periodInfo.start;
+  }
+
   var adaptationSetNodes =
       XmlUtils.findChildren(periodInfo.node, 'AdaptationSet');
   var adaptationSets =
@@ -790,7 +798,7 @@ shaka.dash.DashParser.prototype.parseRepresentation_ = function(
  */
 shaka.dash.DashParser.prototype.onUpdate_ = function() {
   goog.asserts.assert(this.updateTimer_, 'Should only be called by timer');
-  goog.asserts.assert(this.updatePeriod_ > 0,
+  goog.asserts.assert(this.updatePeriod_ >= 0,
                       'There should be an update period');
 
   shaka.log.info('Updating manifest...');
@@ -829,7 +837,7 @@ shaka.dash.DashParser.prototype.onUpdate_ = function() {
  * @private
  */
 shaka.dash.DashParser.prototype.setUpdateTimer_ = function(offset) {
-  if (this.updatePeriod_ == 0)
+  if (this.updatePeriod_ < 0)
     return;
   goog.asserts.assert(this.updateTimer_ == null,
                       'Timer should not be already set');

lib/dash/mpd_utils.js

@@ -100,7 +100,7 @@ shaka.dash.MpdUtils.SegmentInfo;
 shaka.dash.MpdUtils.fillUriTemplate = function(
     uriTemplate, representationId, number, bandwidth, time) {
   if (time !== null) {
-    goog.asserts.assert(Math.abs(time - Math.round(time)) < 0.01,
+    goog.asserts.assert(Math.abs(time - Math.round(time)) < 0.2,
                         'Calculated $Time$ values must be close to integers!');
     time = Math.round(time);
   }

lib/media/segment_index.js

@@ -129,11 +129,10 @@ shaka.media.SegmentIndex.prototype.merge = function(references) {
       shaka.log.warning('Refusing to rewrite original references on update!');
       j++;
     } else {
-      // when period is changed, fitSegmentReference will
-      // expand last segment to the start of the next period
-      // so, it is valid to have end time updated to the
-      // last segment reference in a period
-      if (r1.endTime != r2.endTime) {
+      // When period is changed, fitSegmentReference will expand the last
+      // segment to the start of the next period.  So, it is valid to have end
+      // time updated to the last segment reference in a period
+      if (Math.abs(r1.endTime - r2.endTime) > 0.1) {
         goog.asserts.assert(r2.endTime > r1.endTime &&
             i == this.references_.length - 1 &&
             j == references.length - 1,

test/dash_parser_live_unit.js

@@ -183,9 +183,9 @@ describe('DashParser.Live', function() {
             expect(stream.findSegmentPosition(0)).not.toBe(null);
             Dash.verifySegmentIndex(manifest, basicRefs);
 
-            // 15 seconds for @timeShiftBufferDepth and the first segment
-            // duration.
-            Date.now = function() { return (2 * 15) * 1000; };
+            // 15 seconds for @timeShiftBufferDepth, the first segment duration,
+            // and the @suggestedPresentationDuration.
+            Date.now = function() { return (2 * 15 + 5) * 1000; };
             return delayForUpdatePeriod().then(function() {
               // The first reference should have been evicted.
               expect(stream.findSegmentPosition(0)).toBe(null);

test/segment_index_unit.js

@@ -238,7 +238,7 @@ describe('SegmentIndex', /** @suppress {accessControls} */ function() {
       var references1 = [
         makeReference(1, 10, 20, uri(10)),
         makeReference(2, 20, 30, uri(20)),
-        makeReference(3, 30, 49.987, uri(30))
+        makeReference(3, 30, 49.887, uri(30))
       ];
       var index1 = new shaka.media.SegmentIndex(references1);