Treat absent timeShiftBufferDepth as infinity.

This patch also enables presentations to start in live mode
and end in VOD mode.

Issue #351

Change-Id: Idc0ad0c69887d61d080f844ef388222d1228a535

lib/dash/dash_parser.js

@@ -421,24 +421,16 @@ shaka.dash.DashParser.prototype.parseManifest_ =
   if (this.manifest_) {
     presentationTimeline = this.manifest_.presentationTimeline;
   } else {
-    if (segmentAvailabilityDuration) {
-      // If there's a segment availability window then the presentation is
-      // live.
-      if (presentationStartTime != null) {
-        // Offset the start time by @suggestedPresentationDelay.  This has the
-        // effect of making the segments become available later than they
-        // actually are, so it causes a delay.  Note that the DASH spec
-        // recommends that a default @suggestedPresentationDelay be used when
-        // one is not explicitly specified.
-        presentationStartTime +=
-            suggestedPresentationDelay != null ?
-            suggestedPresentationDelay :
-            shaka.dash.DashParser.DEFAULT_SUGGESTED_PRESENTATION_DELAY_;
-      } else {
-        presentationStartTime = 0;
-      }
-    } else {
-      presentationStartTime = null;
+    if (presentationStartTime != null) {
+      // Offset the start time by @suggestedPresentationDelay.  This has the
+      // effect of making the segments become available later than they
+      // actually are, so it causes a delay.  Note that the DASH spec
+      // recommends that a default @suggestedPresentationDelay be used when
+      // one is not explicitly specified.
+      presentationStartTime +=
+          suggestedPresentationDelay != null ?
+          suggestedPresentationDelay :
+          shaka.dash.DashParser.DEFAULT_SUGGESTED_PRESENTATION_DELAY_;
     }
     presentationTimeline =
         new shaka.media.PresentationTimeline(presentationStartTime);
@@ -468,7 +460,9 @@ shaka.dash.DashParser.prototype.parseManifest_ =
     presentationTimeline.setDuration(duration || Number.POSITIVE_INFINITY);
     presentationTimeline.setClockOffset(offset);
     presentationTimeline.setSegmentAvailabilityDuration(
-        segmentAvailabilityDuration);
+        segmentAvailabilityDuration != null ?
+        segmentAvailabilityDuration :
+        Number.POSITIVE_INFINITY);
 
     if (!this.manifest_) {
       // Use @maxSegmentDuration to override smaller, derived values.

lib/media/playhead.js

@@ -329,12 +329,12 @@ shaka.media.Playhead.prototype.onSeeking_ = function() {
  * @private
  */
 shaka.media.Playhead.prototype.reposition_ = function(currentTime) {
-  var availabilityDuration = this.timeline_.getSegmentAvailabilityDuration();
-  var start = this.timeline_.getEarliestStart();
-  var end = this.timeline_.getSegmentAvailabilityEnd();
+  var timeline = this.timeline_;
+  var start = timeline.getEarliestStart();
+  var end = timeline.getSegmentAvailabilityEnd();
 
-  if (availabilityDuration == null ||
-      availabilityDuration == Number.POSITIVE_INFINITY) {
+  if (!timeline.isLive() ||
+      timeline.getSegmentAvailabilityDuration() == Number.POSITIVE_INFINITY) {
     // If the presentation is live but has an infinite segment availability
     // duration then we can treat it as VOD since the start of the seek range
     // is not moving.

lib/media/presentation_timeline.js

@@ -38,8 +38,8 @@ shaka.media.PresentationTimeline = function(presentationStartTime) {
   /** @private {number} */
   this.duration_ = Number.POSITIVE_INFINITY;
 
-  /** @private {?number} */
-  this.segmentAvailabilityDuration_ = null;
+  /** @private {number} */
+  this.segmentAvailabilityDuration_ = Number.POSITIVE_INFINITY;
 
   /** @private {?number} */
   this.maxSegmentDuration_ = 1;
@@ -93,8 +93,7 @@ shaka.media.PresentationTimeline.prototype.setClockOffset = function(offset) {
  * presentation has a 5 minute DVR window and your segments are 10 seconds long
  * then the segment availability duration should be 4 minutes and 50 seconds.
  *
- * @return {?number} The presentation's segment availability duration.
- *   Always returns null for video-on-demand, and never returns null for live.
+ * @return {number} The presentation's segment availability duration.
  */
 shaka.media.PresentationTimeline.prototype.getSegmentAvailabilityDuration =
     function() {
@@ -104,17 +103,15 @@ shaka.media.PresentationTimeline.prototype.getSegmentAvailabilityDuration =
 
 /**
  * Sets the presentation's segment availability duration. The segment
- * availability duration can only be updated for live.
+ * availability duration should only be set for live.
  *
- * @param {?number} segmentAvailabilityDuration The presentation's new segment
+ * @param {number} segmentAvailabilityDuration The presentation's new segment
  *   availability duration in seconds.
  */
 shaka.media.PresentationTimeline.prototype.setSegmentAvailabilityDuration =
     function(segmentAvailabilityDuration) {
-  goog.asserts.assert(
-      (segmentAvailabilityDuration === null) ||
-          (segmentAvailabilityDuration >= 0),
-      'segmentAvailabilityDuration must be null or >= 0');
+  goog.asserts.assert(segmentAvailabilityDuration >= 0,
+                      'segmentAvailabilityDuration must be >= 0');
   this.segmentAvailabilityDuration_ = segmentAvailabilityDuration;
 };
 
@@ -167,6 +164,16 @@ shaka.media.PresentationTimeline.prototype.notifyMaxSegmentDuration = function(
 };
 
 
+/**
+ * @return {boolean} True if the presentation is live; otherwise, return
+ *   false.
+ */
+shaka.media.PresentationTimeline.prototype.isLive = function() {
+  return this.duration_ == Number.POSITIVE_INFINITY ||
+         this.segmentAvailabilityDuration_ < Number.POSITIVE_INFINITY;
+};
+
+
 /**
  * Gets the presentation's current earliest, available timestamp. This value
  * may be greater than the presentation's current segment availability start
@@ -193,10 +200,8 @@ shaka.media.PresentationTimeline.prototype.getEarliestStart = function() {
  */
 shaka.media.PresentationTimeline.prototype.getSegmentAvailabilityStart =
     function() {
-  if (this.presentationStartTime_ == null ||
-      this.segmentAvailabilityDuration_ == Number.POSITIVE_INFINITY) {
+  if (this.segmentAvailabilityDuration_ == Number.POSITIVE_INFINITY)
     return 0;
-  }
 
   return Math.max(
       0, this.getSegmentAvailabilityEnd() - this.segmentAvailabilityDuration_);
@@ -213,7 +218,7 @@ shaka.media.PresentationTimeline.prototype.getSegmentAvailabilityStart =
  */
 shaka.media.PresentationTimeline.prototype.getSegmentAvailabilityEnd =
     function() {
-  if (this.presentationStartTime_ == null)
+  if (this.presentationStartTime_ == null || !this.isLive())
     return this.duration_;
 
   return Math.min(this.getLiveEdge_(), this.duration_);

lib/player.js

@@ -629,11 +629,9 @@ shaka.Player.prototype.getNetworkingEngine = function() {
  * @export
  */
 shaka.Player.prototype.isLive = function() {
-  if (!this.manifest_) return false;
-
-  //  If the presentation has a segment availability window then it's live.
-  var timeline = this.manifest_.presentationTimeline;
-  return timeline.getSegmentAvailabilityDuration() != null;
+  return this.manifest_ ?
+         this.manifest_.presentationTimeline.isLive() :
+         false;
 };
 
 

test/playhead_unit.js

@@ -57,6 +57,7 @@ describe('Playhead', function() {
       }
     });
 
+    timeline.isLive.and.returnValue(false);
     timeline.getEarliestStart.and.returnValue(5);
     timeline.getSegmentAvailabilityStart.and.returnValue(5);
     timeline.getSegmentAvailabilityEnd.and.returnValue(60);
@@ -174,6 +175,7 @@ describe('Playhead', function() {
       }
     };
 
+    timeline.isLive.and.returnValue(true);
     timeline.getEarliestStart.and.returnValue(5);
     timeline.getSegmentAvailabilityStart.and.returnValue(5);
     timeline.getSegmentAvailabilityEnd.and.returnValue(60);
@@ -327,6 +329,7 @@ describe('Playhead', function() {
       }
     };
 
+    timeline.isLive.and.returnValue(false);
     timeline.getEarliestStart.and.returnValue(5);
     timeline.getSegmentAvailabilityStart.and.returnValue(5);
     timeline.getSegmentAvailabilityEnd.and.returnValue(60);
@@ -382,6 +385,7 @@ describe('Playhead', function() {
       setDuration: jasmine.createSpy('setDuration'),
       getSegmentAvailabilityDuration:
           jasmine.createSpy('getSegmentAvailabilityDuration'),
+      isLive: jasmine.createSpy('isLive'),
       getEarliestStart: jasmine.createSpy('getEarliestStart'),
       getSegmentAvailabilityStart:
           jasmine.createSpy('getSegmentAvailabilityStart'),