Doc Example

The idea

The idea behind the synchronization feature is to allow you to synchronize separate media players (Android and/or Windows) to play the same content at the same time or to play different content to be synchronized very similar to a video wall effect.

const trigger = item.querySelector('[data-accordion_trigger]');
      const content = item.querySelector('[data-accordion_content]');
      content.style.maxHeight = 0;
      trigger.addEventListener("click", function () {
        if (item.classList.contains("is-active")) {
          closeAccordion(item, content);
        } else {
          accordionItems.forEach(i => {
            if (i.classList.contains("is-active")) {
              closeAccordion(i, i.querySelector('[data-accordion_content]'));
            }
          });
          openAccordion(item, content);
        }
      });

When to use this feature?

This feature can come in handy in case you do not have professional displays which you can daisy chain into a video wall or if you do not wish to buy an expensive switcher (that splits the signal over multiple connected displays in a few pre-defined layouts). Also, if you need to display content in many displays in high resolution, it will be easier to be done using this feature rather than the 2 above mentioned options. Lastly, if you have many units (imagine an electrical appliances store which sells TVs) which you’d like to play the same content, you can use this feature.

const trigger = item.querySelector('[data-accordion_trigger]');
      const content = item.querySelector('[data-accordion_content]');
      content.style.maxHeight = 0;
      trigger.addEventListener("click", function () {
        if (item.classList.contains("is-active")) {
          closeAccordion(item, content);
        } else {
          accordionItems.forEach(i => {
            if (i.classList.contains("is-active")) {
              closeAccordion(i, i.querySelector('[data-accordion_content]'));
            }
          });
          openAccordion(item, content);
        }
      });

Web NTP or local NTP?

First, you need to understand that this feature’s heart is NTP server. What does that mean? It means that we use an NTP (Network Time Protocol) server to synchronize the clock of each unit to be synced. This is how we get this effect. NTP can be an app installed on a local device (even on one that participates in the display) or a web NTP service.

If you have only few devices to synchronize, you can use a web NTP service rather than installing a local NTP app or one of the media players. Using a web NTP is very simple, but in case of no internet or too many calls from your devices to the web NTP server (that might be blocked by that NTP server), better install one.

For using a web NTP service, just search Google for one which is in your country. For example, in Germany the free web NTP URL is de.pool.ntp.org, in France it will be fr.pool.ntp.org and so on. If you’re using a web NTP, better have all your synced devices on the very same local network for better performance.

If you’re about to install an NTP app, then you’ll find the instructions for that in the end of this manual.

For best performance, better have all your synced devices from the same brand, model and firmware.

Content restrictions

You must follow all the 4 guidelines for content. Otherwise it won’t work:

• Your playlist should have only ONE creative (however you can put, for example, more than one playlist if they do not overlap: example: one playlist plays from 8:00 till 16:00 and the other playlist plays from 16:00 till 21:00).
• That creative should have at least ONE slideshow widget.
• That slideshow widget must have at least TWO slides (doesn’t matter if they’re video, image, text or else). If, for example, you want to show only one video, then the workaround is to put that video twice, that means 2 slides where each of them is that same video.
• The duration of the creative must be an INTEGER. If it is a fracture (because the duration of a video which you have put in any of the slides in the slideshow widget is not an integer), better enter the slideshow widget and then manually set an integer value for each video slide of yours (there might be a
bug there where you see an integer, but in fact it is a fraction – which eventually appears in the duration of the whole creative). That should adjust the duration of the whole creative to be an integer.

const trigger = item.querySelector('[data-accordion_trigger]');
      const content = item.querySelector('[data-accordion_content]');
      content.style.maxHeight = 0;
      trigger.addEventListener("click", function () {
        if (item.classList.contains("is-active")) {
          closeAccordion(item, content);
        } else {
          accordionItems.forEach(i => {
            if (i.classList.contains("is-active")) {
              closeAccordion(i, i.querySelector('[data-accordion_content]'));
            }
          });
          openAccordion(item, content);
        }
      });

Android player settings configuration

If this is Android media player, before everything go to the Android settings, then to the date/time settings, make sure the correct timezone is chosen (if not, turn off the setting that takes the date/time from the network, then choose the correct timezone and finally turn on the setting to take the date/time from the network). Then make sure that the date/time is indeed taken from the network. This may save you later trouble.

Player app configuration

Download and install the Android app and/or the Windows app.

The settings you need to change are:

Only if this is Android unit, then under the “Display” block of settings you MUST alter the “Video to video transitions” to “Background”.
Then proceed to the “Play Sync” block of settings, access it in order to reach the following list of clock sync settings.

Playback Clock
When ON, binds slide playback trigger timing to a clock. You should set this to ON.

Reference Time
Starting point for sync calculation. Should be at least few rounds before the venue is open but enough time after connectivity window close, to allow completing all updates. The default 6:00. You should change it maybe to one hour before the venue with your digital signs opens.

Clock Server
Enter the permanent IP address of an NTP server on standard port 123 (or IP address:port if a custom port was set). You should type the local static IP address of the NTP server which you set above (example: 10.100.102.5). If you use a web NTP, just type it (something like de.pool.ntp.org, for example).

Clock Update
Clock refresh interval, the default is 1 minute, should be good for LAN. No need to change anything here.

Wait for clock
On player start will not start playback until initial sync was performed. When server is online, usually the sync is performed far before the playback start. Currently, this setting or Timing Debug window are the only tools to verify time server connection. Better turn this off, as you don’t want your content to stop playing whenever there is no connection to the NTP server/app.

Video Accommodation
Delay before starting video playback.
Various devices have different delays on preparing video before playing, some like Minix also have bugs hanging UI for random 1 – 2 sec while probing MP4 format.
This delay can vary significantly even across same device types and will result in loss of synchronization even when while having perfect pulses. More delay gives more room to amortize these differences between devices on the expense of a black screen between videos. The default is 2 seconds but can be reduced for fast devices (it should be maximum of possible video load delay among all synchronized devices). No need to change anything here.

Timing Debug
Shows blinking sync indicator and sync traces on top of the content.
If there is a problem, but the indicators on the different media players are blinking seemingly simultaneously, it means that the players are in sync and the problem is not with pulse synchronization. When the clock server cannot be reached, the indicator becomes yellow (for around 24 hours) and then red (players still can be in sync for a while if initial update was successful, until clocks diverge too much, on good devices it can be days).

How does it behave?

On the first round, it will be out of sync until the players come to the next item. They are expected to start on the same video, but since they do not start at the same time (it is impossible even if start triggered by perfect sync) they will play different parts of the same video. Then they should stop this video simultaneously and play next item together.
They also may be slightly out of sync until device is ‘warmed up’ – the content is cached and the device boot duties are finished. Until then, weak devices may have long, varying delays for loading the video but probably would sort it out after some time.

Windows NTP server installation & setup

In the Windows based machine which is going to be used as the NTP server, make sure you have set a static IP address.
Go to the Control Panel -> Date and Time -> Internet Time -> Change settings… -> now check the checkbox of “Synchronize with an Internet time server” (if it is not checked) and press the “Update now” in order to update the Windows time from internet (this will put the clock in sync). Then uncheck that checkbox (so it will not hold NTP port 123) and press “OK”.

In the Windows firewall, open port 123 for inbound and outbound calls for the private network.
Once in a while (a week would be fine) stop the NTP with the monitor (which will be installed later) below and sync again with internet time (this can be automated with nightly batch file). The ideal is that the server clock will not be updated from internet during opening hours of your venue, to avoid sudden time jumps which can result in loss of sync for some time. It can be run scheduled during connectivity window.
Note the player the can connect to any custom port if the server supports it, but there seems no such setting for the server below.
For the NTP server, install this: https://www.meinbergglobal.com/english/sw/ntp.htm
For the NTP monitor, install this: https://www.meinbergglobal.com/english/sw/ntp-server-monitor.htm
While installing, do not change the defaults.

Comment the lines (by adding # in the beginning of the line):
# restrict -6 ::1 (since we have no need for ipv6)
# server pool.ntp.org iburst minpoll 6 maxpoll 7 (not sure you’ll find this line at all, but the idea here is that this NTP server will serve from its local clock and not from the internet with an undefined period)

Run the NTP monitor as administrator (go to C:\Program Files\meinberg\ntp_time_server_monitor, right click the file mbgtsmon.exe and choose “Run as administrator”). Restart the NTP service: in the first tab, “NTP Service”, click the “Restart NTP Service”. You need to make sure that the service status is changed to “Stopped” and then to “started”. Also, notice that the “Start Type” of the service is set to “Automatically”

In the third tab, “NTP Configuration File”, you can alter the configuration (rather than using Notepad++), in case you need.
In the second tab, “NTP Status” you should see a “LOCAL” entry only.

Android NTP server installation & setup

If you like, you can install an NTP server for Android, which can run on one of your Android units (which also serves as a signage player). This way, no need for another machine and no need to use Windows.

Here are the instructions:

1. Search the Google Play store for “time server” or another NTP reliable app.
2. One of the first results should be “Time Server” (by Ice Cold Apps).
3. Install this app and then open it.
4. Every time when you start the app, you need to press the “Continue” button.
5. In the top button bar, press the “Add” button, in order to add an NTP server.
   
6. Now, you have to fill some details:
   1. In the “Server name” field, give it any name you like (i.e. “My NTP Server”).
   2. In the “Run on port”, you can stay with the default or press the “Get random port” button which will randomize a port number for you (i.e. let’s assume that the port is 41700).
   3. Check the “Start on boot” checkbox.

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Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum

Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum

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Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum

Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum

Example

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Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum