From 9cfd533a03aa462bffb6095eb66c3473b80bf182 Mon Sep 17 00:00:00 2001
From: Jibben Nee <ziddey@ijib.com>
Date: Thu, 11 Mar 2021 01:54:28 +0000
Subject: [PATCH 1/4] fix: support timeshift dash manifests without startNumber
 attribute

---
 src/dash-playlist-loader.js | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/dash-playlist-loader.js b/src/dash-playlist-loader.js
index 1c96825dd..586cddacd 100644
--- a/src/dash-playlist-loader.js
+++ b/src/dash-playlist-loader.js
@@ -24,6 +24,20 @@ import logger from './util/logger';
 const { EventTarget, mergeOptions } = videojs;
 
 const dashPlaylistUnchanged = function(a, b) {
+  // derive media sequence for timeshift manifests without startNumber attribute
+  if (
+    b.mediaSequence === 1 &&
+    a.segments &&
+    b.segments &&
+    a.segments.length &&
+    b.segments.length
+  ) {
+    const seqDelta = a.segments.findIndex((s) => s.uri === b.segments[0].uri);
+
+    b.mediaSequence =
+      a.mediaSequence + (seqDelta === -1 ? a.segments.length : seqDelta);
+  }
+
   if (!isPlaylistUnchanged(a, b)) {
     return false;
   }

From 6967321301ad9a539d4e92ee78b31df6a7f156f3 Mon Sep 17 00:00:00 2001
From: Jibben Nee <ziddey@ijib.com>
Date: Thu, 11 Mar 2021 10:25:51 +0000
Subject: [PATCH 2/4] fix: dash group changes should not stop playlist loader

---
 src/media-groups.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/media-groups.js b/src/media-groups.js
index 63de67aec..22bf6a961 100644
--- a/src/media-groups.js
+++ b/src/media-groups.js
@@ -71,6 +71,7 @@ export const startLoaders = (playlistLoader, mediaType) => {
  */
 export const onGroupChanged = (type, settings) => () => {
   const {
+    sourceType,
     segmentLoaders: {
       [type]: segmentLoader,
       main: mainSegmentLoader
@@ -81,6 +82,11 @@ export const onGroupChanged = (type, settings) => () => {
   const activeGroup = mediaType.activeGroup(activeTrack);
   const previousActiveLoader = mediaType.activePlaylistLoader;
 
+  if (sourceType === 'dash') {
+    // only one playlist loader for dash. do not stop.
+    return;
+  }
+
   stopLoaders(segmentLoader, mediaType);
 
   if (!activeGroup) {

From b0dcefdbd2813473e7b7e5d0d9e99526a942c3ed Mon Sep 17 00:00:00 2001
From: Jibben Nee <ziddey@ijib.com>
Date: Tue, 30 Mar 2021 04:17:48 +0000
Subject: [PATCH 3/4] add additional condition

should allow tests to pass now
---
 src/dash-playlist-loader.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/dash-playlist-loader.js b/src/dash-playlist-loader.js
index bd52b1015..7ec7f0a2c 100644
--- a/src/dash-playlist-loader.js
+++ b/src/dash-playlist-loader.js
@@ -28,6 +28,7 @@ const dashPlaylistUnchanged = function(a, b) {
   // derive media sequence for timeshift manifests without startNumber attribute
   if (
     b.mediaSequence === 1 &&
+    b.mediaSequence <= a.mediaSequence &&
     a.segments &&
     b.segments &&
     a.segments.length &&

From b8480063d1b49cfd6dea477a235e36ef63ac7637 Mon Sep 17 00:00:00 2001
From: Jibben Nee <ziddey@ijib.com>
Date: Tue, 6 Apr 2021 22:29:16 +0000
Subject: [PATCH 4/4] only prevent stopLoaders for dash (fix for recent
 updates)

---
 src/media-groups.js | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/src/media-groups.js b/src/media-groups.js
index fcefa039e..b0cd8760f 100644
--- a/src/media-groups.js
+++ b/src/media-groups.js
@@ -93,13 +93,11 @@ export const onGroupChanged = (type, settings) => () => {
   mediaType.lastGroup_ = activeGroup;
   mediaType.lastTrack_ = activeTrack;
 
-  if (sourceType === 'dash') {
-    // only one playlist loader for dash. do not stop.
-    return;
+  if (sourceType !== 'dash') {
+    // only one playlist for dash. do not stop.
+    stopLoaders(segmentLoader, mediaType);
   }
 
-  stopLoaders(segmentLoader, mediaType);
-
   if (!activeGroup || activeGroup.isMasterPlaylist) {
     // there is no group active or active group is a main playlist and won't change
     return;