This object provides PTP synchronization capabilities for video walls and other deployments that require closely calibrated interaction among players. roSyncManager handles all network traffic for master/slave synchronization, including the network clock. Multiple synchronization groups are allowed on the same local network and even within the same video wall.
The roSyncManager object currently supports video, image, and scrolling ticker synchronization. The roVideoPlayer and roImagePlayer objects rely on values generated by the ifSyncManager and roSyncManagerEvent methods to synchronize playback, while the roTextWidget object simply requires the domain name of the roSyncManager instance.
As of firmware version 7.0, roSyncManager also supports Genlock synchronization (frame-accurate VSync) over Ethernet. To enable Genlock on an roSyncManager domain, pass the domain name to the roVideoMode.SetSyncDomain() method. Otherwise, the process for synchronizing video, image, and ticker playback is the same.
The roSyncManager object supports synchronization over Ethernet networks only.
Before using roSyncManager, you will need to instantiate a synchronization group by setting all players within the group to the same PTP domain value. To do this, use the roRegistrySection.Write() method to set the
ptp_domain key of the “networking” section to a value between 0 and 127. In general, changes to the registry only take effect after a reboot, so the PTP synchronization service will start on each player after it is rebooted.
Object Creation: The roSyncManager object is created with an associative array representing a set of parameters.
The associative array can have the following parameters:
[string] Domain: An identifier that is used to distinguish among different roSyncManager instances within the same synchronization group (i.e. PTP domain). The default string is "BrightSign". This parameter allows multiple roSyncManager instances to operate at the same time.
[string] MulticastAddress: The multicast address to which synchronization messages are communicated. The default address is "126.96.36.199".
[string] MulticastPort: The multicast port to which synchronization messages are communicated. The default port is "1539".
SetPort(port As roMessagePort)
Posts messages of type roSyncManagerEvent to the attached message port. Use these messages to synchronize roVideoPlayer and roImagePlayer playback.
SetMasterMode(master_mode As Boolean) As Boolean
Specifies whether the unit is running the master instance of roSyncManager.
Synchronize(identifier As String, ms_delay As Integer) As Object
Broadcasts a time-stamped message to other players. This method is used on the master unit only. The message will be rebroadcasted every second to allow slave units that are powered on late to catch up. The network message contains the sync ID, as well as the domain and a timestamp. The timestamp is created at the point when this method is called; however, it can be offset by passing a non-zero
ms_delay value, allowing synchronization points to be set slightly in the future and giving the client enough time to switch video files and perform other actions. The
identifier parameter allows the script on the master unit to pass a filename, or some other useful marker, to the slave units as part of the synchronization message. This method returns the message that is sent out so that the master can access the timestamp.
The synchronization message is sent over all available networks (including WiFi), but slave units will use only the first message received. The PTP messages, which are used by the firmware during synchronization, are sent over Ethernet only.
Because synchronization can involve slave units seeking to catch up with the playback of a master unit, we recommend using the more efficient MOV/MP4 container format when synchronizing video files. Transport Stream files (MPEG-TS) are also supported, but they must begin with a presentation timestamp (PTS) of 0. Program Stream files (MPEG-PS) are not supported.
Currently, there are two objects that can accept synchronization parameters: The roVideoPlayer.PlayFile() call accepts the parameters provided by SyncManagerEvent messages, while the roImagePlayer.DisplayFile() and roImagePlayer.PreloadFile() calls accept
SyncIsoTimestamp in an associative array. To synchronize image playback, an roImagePlayer object will simply delay the transition thread prior to running the transition. If there is a separate call for
DisplayFile(), then the transition will be cancelled and the image will be displayed immediately (as with non-synchronized
The following script synchronizes video playback on the master and slave units.