Synchronization Feature

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.

• If you don’t have professional displays that can be daisy-chained into a video wall.

• If you want to avoid buying costly signal splitters or switchers.

• When you want to show high-resolution content across many displays easily.

• If you have multiple devices (for example, in a store selling TVs) that should all play the same content.

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.

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.

Before starting, make sure your Android device is set to the correct time-zone:

1. Go to Android Settings > Date & Time.

2. If automatic date/time is on but the time-zone is wrong, turn it off.

3. Set the correct time-zone manually.

4. Turn automatic date/time back on to sync with the network.

1. Install the NoviSign app on your devices.

2. Android Only: In the app settings under “Display,” set “Video to video transitions” to Background.

3. Go to the “Play Sync” settings to configure clock synchronization.

• Playback Clock: Turn ON to sync playback trigger timing with the clock.

• 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).
  “post delay=xxx” line shows the delay until the accommodation point. If it is zero, accommodation value is not enough. While it is constantly above 500 seconds on all devices, it may be safe to reduce it more to shorten black screen period (if desired).
  No need to change anything here, but we recommend to start when this setting is turned on, so you’ll be able to know if this unit is synced (green circle in the top left corner) or not synced (red or yellow circle in the top left corner). Later on, turn this setting to off.

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.