How to Analyze the Channel / Movie Start Delay

When the subscriber switches on a TV channel or starts watching a movie, there is some delay between the moment of pressing a key on the remote control and the start of playback. Sometimes this delay can become too large and uncomfortable for subscribers. SmartCARE allows you to analyze the reasons that led to such situations.

What does SmartCARE have to offer?

You can get information about such problems in various ways:

by receiving reports from subscribers,
analyzing Abnormal clusters,
noticing a drop in session quality,
and others.

Regardless of the way above, the analysis of the playback start delay is performed on a specific device. By going to the SmartCARE Console > Sessions > Device info, you can find the problematic device by its UID or MAC:

Having found the device, you can see what happened with streaming on it. The most essential data are located in the Events and sessions section:

Each line of this graph represents an event of a certain type. These events are passed to the SmartCARE by client applications upon the occurrence of certain conditions.

Here you can find Join time events, which show the time between a subscriber pressing a button on the remote control (not releasing the button) and the start of playback, in msec. This way you can find sessions when the subscriber has suffered from too long waiting time for the channel or movie to start.

After you find abnormal Join time on the graph you can also look at additional parameters passed with this event. Remember the time of such event, switch to the Table tab and find it by time:

The jointime event can pass the following additional parameters:

The time between a subscriber pressing a button on the remote control (not releasing the button) and the start of playback.

API Request Parameter	Type	Description	Player
API Request Parameter	Type	Description	Shaka	HLSJS	Cobalt + ExoPlayer	iOS	Android
e=JOIN_TIME	String	Event type	+	+	+	+	+
values	Integer	The time between a subscriber pressing a button on the remote control (not releasing the button) and the start of playback, in ms.	+	+	+	+	+
Parameters that directly affect the start time of the stream
mnft	Double	Amount of time it took to download and parse the manifest, in seconds.	+	+	+	Roadmap	N/A
drmt	Double	Amount of time it took to download the first DRM key, in seconds.	+	N/A	Roadmap	N/A	+
lct	Double	Time spent on license requests during this session, in seconds.	+	N/A	Roadmap	N/A	+
ldl	Double	Time it took for the video element to have enough data to begin playback, in seconds. This is measured from the time the player’s load() function is called to the time the ‘loadeddata’ event is fired by the media element.	+	+	N/A	N/A	+
Reference parameters
dt	String	Device type	+	+	+	+	+
bfu	Integer	Loading buffer occupancy (%). The ratio of the time of viewing the content by the subscriber to the time of its buffering. For the JOIN_TIME event, this parameter should be equal to 100%, since playback has not started yet.	+	+	+	N/A	Roadmap
ibr	Integer	NOT USED: Not sent by devices. Incoming stream bitrate, in bit/sec.	–	–	–	–	–
msd	Double	Presentation’s max segment duration: The duration of the longest segment described in the first loaded MPEG-DASH playlist at the moment of session start.	+	+	N/A	N/A	+
ll	Double	Time between the frame display on the screen and its output to the air by the head-end, in seconds.	+	+	N/A	N/A	Roadmap
bft	Double	Total time spent in a buffering state, in seconds.	+	+	+	N/A	+
ebw	Double	Current estimated network bandwidth, in bit/sec.	+	+	+	N/A	+
pdc	Integer	Number of frames played	+	+	+	N/A	+
pdec	Integer	Number of frames with decoding errors	+ (non-zero value)	+	+	N/A	Roadmap
pbr	Integer	The bandwidth required for the current streams (total, in bit/sec). It takes into account the playback rate.
abr	Array of integers	Available bitrates, in bit/sec.
bdr	Integer	Buffer size, in sec.
btr	Integer	Average bitrate calculated by the video PES packet, in bit/sec.
dbr	Integer	Downloading bitrate, in bit/sec.
dec	Integer	Number of frames with errors	+ (non-zero value)	+	+	N/A	Roadmap
ufc	Integer	Number of loading buffer underrun events (client application STVID_DATA_UNDERFLOW_EVT event). For the JOIN_TIME event, this parameter should be equal to 1.	+	+	+	N/A	+
fr	Integer	Number of frames (not fields) per second multiplied by 1000. For example, 24 fps is recorded as 24000.
url	String	URL of the content playlist/manifest	+	+	+	+	+

Now, in order to analyze this data for the cause of the large Join time, we need to understand the processes that occur during the stream start.

Process of Starting the TV Channel / Movie Playback

The Join time consists of the following chain of events, each of which can be analyzed using additional parameters:

https://view.genially.com/630c7e8550ebcc001183dc50/guide-stream-playback-starting

Knowing this sequence, you can understand where to look for the cause of a large delay in the playback start.

How to Analyze the Channel / Movie Start Delay

What does SmartCARE have to offer?

Process of Starting the TV Channel / Movie Playback

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