From 9e3da3cb35da71d339444158db359bfec63035a0 Mon Sep 17 00:00:00 2001
From: Matthias <matvp91@gmail.com>
Date: Tue, 6 Feb 2024 13:06:19 +0100
Subject: [PATCH] Added liveUpdateTimeThreshold to control time syncing during
 live streams (#4382)

* Added liveUpdateTimeThresholdInMilliseconds in order to control the frequency of time updates during live streams
---
 index.d.ts                                      |  1 +
 src/core/Settings.js                            |  4 ++++
 src/streaming/controllers/PlaybackController.js | 16 +++++++++++-----
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/index.d.ts b/index.d.ts
index cdbe0a2367..3dbc1ea5f9 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -963,6 +963,7 @@ declare namespace dashjs {
             abandonLoadTimeout?: number,
             wallclockTimeUpdateInterval?: number,
             manifestUpdateRetryInterval?: number,
+            liveUpdateTimeThresholdInMilliseconds?: number,
             applyServiceDescription?: boolean,
             applyProducerReferenceTime?: boolean,
             applyContentSteering?: boolean,
diff --git a/src/core/Settings.js b/src/core/Settings.js
index 7e4f66d6a7..bbc8a87343 100644
--- a/src/core/Settings.js
+++ b/src/core/Settings.js
@@ -62,6 +62,7 @@ import Events from './events/Events';
  *            abandonLoadTimeout: 10000,
  *            wallclockTimeUpdateInterval: 100,
  *            manifestUpdateRetryInterval: 100,
+ *            liveUpdateTimeThresholdInMilliseconds: 0,
  *            cacheInitSegments: false,
  *            applyServiceDescription: true,
  *            applyProducerReferenceTime: true,
@@ -744,6 +745,8 @@ import Events from './events/Events';
  * How frequently the wallclockTimeUpdated internal event is triggered (in milliseconds).
  * @property {number} [manifestUpdateRetryInterval=100]
  * For live streams, set the interval-frequency in milliseconds at which dash.js will check if the current manifest is still processed before downloading the next manifest once the minimumUpdatePeriod time has.
+ * @property {number} [liveUpdateTimeThresholdInMilliseconds=0]
+ * For live streams, postpone syncing time updates until the threshold is passed. Increase if problems occurs during live streams on low end devices.
  * @property {boolean} [cacheInitSegments=false]
  * Enables the caching of init segments to avoid requesting the init segments before each representation switch.
  * @property {boolean} [applyServiceDescription=true]
@@ -874,6 +877,7 @@ function Settings() {
             abandonLoadTimeout: 10000,
             wallclockTimeUpdateInterval: 100,
             manifestUpdateRetryInterval: 100,
+            liveUpdateTimeThresholdInMilliseconds: 0,
             cacheInitSegments: false,
             applyServiceDescription: true,
             applyProducerReferenceTime: true,
diff --git a/src/streaming/controllers/PlaybackController.js b/src/streaming/controllers/PlaybackController.js
index d0ce36d9c7..9f751adb75 100644
--- a/src/streaming/controllers/PlaybackController.js
+++ b/src/streaming/controllers/PlaybackController.js
@@ -58,6 +58,7 @@ function PlaybackController() {
         isDynamic,
         playOnceInitialized,
         lastLivePlaybackTime,
+        lastLiveUpdateTime,
         availabilityStartTime,
         availabilityTimeComplete,
         lowLatencyModeEnabled,
@@ -88,6 +89,7 @@ function PlaybackController() {
         lowLatencyModeEnabled = false;
         initialCatchupModeActivated = false;
         seekTarget = NaN;
+        lastLiveUpdateTime = NaN;
 
         if (videoModel) {
             eventBus.off(Events.DATA_UPDATE_COMPLETED, _onDataUpdateCompleted, instance);
@@ -723,11 +725,15 @@ function PlaybackController() {
         // Updates playback time for paused dynamic streams
         // (video element doesn't call timeupdate when the playback is paused)
         if (getIsDynamic()) {
-            streamController.addDVRMetric();
-            if (isPaused()) {
-                _updateLivePlaybackTime();
-            } else {
-                updateCurrentTime();
+            const now = Date.now();
+            if (isNaN(lastLiveUpdateTime) || now > lastLiveUpdateTime + settings.get().streaming.liveUpdateTimeThresholdInMilliseconds) {
+                streamController.addDVRMetric();
+                if (isPaused()) {
+                    _updateLivePlaybackTime();
+                } else {
+                    updateCurrentTime();
+                }
+                lastLiveUpdateTime = now;
             }
         }
     }