From a8e3c9ab310b14ca71610c568cffe108b30d38bf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=81lvaro=20Velad=20Galv=C3=A1n?= <ladvan91@hotmail.com>
Date: Fri, 28 Apr 2023 07:02:41 +0200
Subject: [PATCH] fix: Fix buffering on the end of MSS streams (#5196)

---
 lib/mss/mss_parser.js | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/lib/mss/mss_parser.js b/lib/mss/mss_parser.js
index 9e5c42d363..87ea5444a3 100644
--- a/lib/mss/mss_parser.js
+++ b/lib/mss/mss_parser.js
@@ -54,6 +54,9 @@ shaka.mss.MssParser = class {
      */
     this.updatePeriod_ = 0;
 
+    /** @private {?shaka.media.PresentationTimeline} */
+    this.presentationTimeline_ = null;
+
     /**
      * An ewma that tracks how long updates take.
      * This is to mitigate issues caused by slow parsing on embedded devices.
@@ -286,12 +289,8 @@ shaka.mss.MssParser = class {
       manifestPreprocessor(mss);
     }
 
-    /** @type {!shaka.media.PresentationTimeline} */
-    let presentationTimeline;
-    if (this.manifest_) {
-      presentationTimeline = this.manifest_.presentationTimeline;
-    } else {
-      presentationTimeline = new shaka.media.PresentationTimeline(
+    if (!this.presentationTimeline_) {
+      this.presentationTimeline_ = new shaka.media.PresentationTimeline(
           /* presentationStartTime= */ null, /* delay= */ 0);
     }
 
@@ -305,7 +304,7 @@ shaka.mss.MssParser = class {
           shaka.util.Error.Code.MSS_LIVE_CONTENT_NOT_SUPPORTED);
     }
 
-    presentationTimeline.setStatic(!isLive);
+    this.presentationTimeline_.setStatic(!isLive);
 
     const timescale = XmlUtils.parseAttr(mss, 'TimeScale',
         XmlUtils.parseNonNegativeInt, shaka.mss.MssParser.DEFAULT_TIME_SCALE_);
@@ -342,7 +341,7 @@ shaka.mss.MssParser = class {
       segmentAvailabilityDuration = Infinity;
     }
 
-    presentationTimeline.setSegmentAvailabilityDuration(
+    this.presentationTimeline_.setSegmentAvailabilityDuration(
         segmentAvailabilityDuration);
 
     // Duration in timescale units.
@@ -352,7 +351,7 @@ shaka.mss.MssParser = class {
         'Duration must be defined!');
 
     if (!isLive) {
-      presentationTimeline.setDuration(duration / timescale);
+      this.presentationTimeline_.setDuration(duration / timescale);
     }
 
     /** @type {!shaka.mss.MssParser.Context} */
@@ -368,7 +367,7 @@ shaka.mss.MssParser = class {
     // These steps are not done on manifest update.
     if (!this.manifest_) {
       this.manifest_ = {
-        presentationTimeline: presentationTimeline,
+        presentationTimeline: this.presentationTimeline_,
         variants: context.variants,
         textStreams: context.textStreams,
         imageStreams: [],
@@ -382,7 +381,7 @@ shaka.mss.MssParser = class {
       // This is the first point where we have a meaningful presentation start
       // time, and we need to tell PresentationTimeline that so that it can
       // maintain consistency from here on.
-      presentationTimeline.lockStartTime();
+      this.presentationTimeline_.lockStartTime();
     } else {
       // Just update the variants and text streams.
       this.manifest_.variants = context.variants;
@@ -491,6 +490,10 @@ shaka.mss.MssParser = class {
       duration = end - start;
     }
 
+    const presentationDuration = this.presentationTimeline_.getDuration();
+    this.presentationTimeline_.setDuration(
+        Math.min(duration, presentationDuration));
+
     /** @type {!shaka.extern.Stream} */
     const stream = {
       id: id,