From eda4e01bbec503a7bf52b6bd500d1361c3d8171e Mon Sep 17 00:00:00 2001
From: Matthew Neil <mjneil@users.noreply.github.com>
Date: Thu, 5 Oct 2017 17:40:41 -0400
Subject: [PATCH] comments and mappingForTimeline

---
 src/master-playlist-controller.js | 4 ++++
 src/segment-loader.js             | 6 ++++--
 src/sync-controller.js            | 9 +++++++--
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/master-playlist-controller.js b/src/master-playlist-controller.js
index 68e9b810e..df4377a2b 100644
--- a/src/master-playlist-controller.js
+++ b/src/master-playlist-controller.js
@@ -609,10 +609,14 @@ export class MasterPlaylistController extends videojs.EventTarget {
     });
 
     this.mainSegmentLoader_.on('reseteverything', () => {
+      // If playing an MTS stream, a videojs.MediaSource is listening for
+      // hls-reset to reset caption parsing state in the transmuxer
       this.tech_.trigger('hls-reset');
     });
 
     this.mainSegmentLoader_.on('segmenttimemapping', (event) => {
+      // If playing an MTS stream in html, a videojs.MediaSource is listening for
+      // hls-segment-time-mapping update its internal mapping of stream to display time
       this.tech_.trigger({
         type: 'hls-segment-time-mapping',
         mapping: event.mapping
diff --git a/src/segment-loader.js b/src/segment-loader.js
index b735a40a4..39c82b7d0 100644
--- a/src/segment-loader.js
+++ b/src/segment-loader.js
@@ -1119,10 +1119,12 @@ export default class SegmentLoader extends videojs.EventTarget {
       this.trigger('timestampoffset');
     }
 
-    if (timingInfo && timingInfo.hasMapping) {
+    const timelineMapping = this.syncController_.mappingForTimeline(segmentInfo.timeline);
+
+    if (timelineMapping !== null) {
       this.trigger({
         type: 'segmenttimemapping',
-        mapping: this.syncController_.timelines[segmentInfo.timeline].mapping
+        mapping: timelineMapping
       });
     }
 
diff --git a/src/sync-controller.js b/src/sync-controller.js
index cbe0a1e45..ede098459 100644
--- a/src/sync-controller.js
+++ b/src/sync-controller.js
@@ -380,8 +380,6 @@ export default class SyncController extends videojs.EventTarget {
             time: segment.start
           };
         }
-
-        timingInfo.hasMapping = true;
       }
     }
 
@@ -453,6 +451,13 @@ export default class SyncController extends videojs.EventTarget {
     return this.timelines[timeline].time;
   }
 
+  mappingForTimeline(timeline) {
+    if (typeof this.timelines[timeline] === 'undefined') {
+      return null;
+    }
+    return this.timelines[timeline].mapping;
+  }
+
   /**
    * Use the "media time" for a segment to generate a mapping to "display time" and
    * save that display time to the segment.