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Viz Ticker User Guide

Version 3.1 | Published May 27, 2020 ©

Shared Memory Support

Viz Ticker supports the Viz Engine Shared Memory (SHM) functionality. Combining Field Linking with the Viz Engine ApplySharedMemory plug-in provides an easy way to update data instantly. A typical scenario would be updating stock prices where the actual stock values are fetched from external data sources and the ticker displaying the stock values are updated in near realtime.

The combination of Field Linking and SHM allows the user of Viz Ticker Client to simply select an item using Field Linking, which behind the scenes extracts information from the feed item, including the locator element (the key used to set the data in the ApplySharedMemory plug-in). Realtime data can be sent to the ApplySharedMemory plug-in using any application that supports it, for instance Viz DataHub. It could also be any custom application sending data via UDP, TCP or by sending commands directly to the Viz Engine.

IMPORTANT! This functionality requires Viz Engine 3.7 (REV 43635) or above.

Configure Field Linking and SHM support

The Viz Engine used must be configured for Shared Memory Support and the port used for communication must be agreed upon. In Viz Artist go to Configuration > Communication > Shared Memory-tab. In the example below, we use TCP on port 11000 for communication.

images/download/attachments/28389610/fieldlinking_vizconfig_shared_memory1.png

Design and configure the scene to be used as a ticker for SHM. A typical scene tree is shown below:

images/download/attachments/28389610/fieldlinking_smm_scene_tree.png
Make sure the ApplySharedMemory plug-in is configured:

images/download/attachments/28389610/fieldlinking_smm_apply_shared_mem_plugin.png
You can now use Ticker Wizard and Field Linking with Shared Memory support using the SHM key/value combination you have chosen.

Realtime data updates

Use any custom application to send updates to the port you have configured for SHM use. The message must include the SHM key and the value. The key should be in /YOUR_SHARED_MEMORY_BASE_KEY/PERHAPS_WITH_PATH/value format.

The Viz Engine is shipped with an example implementation (using C#) showing you how to send data to the engine. The source is typically installed in the directory <Viz Artist-Engine Installation Directory>\SendToSMM. Using this requires compiler and programming experience, so end users should have other tools prepared for sending data to SHM enabled tickers.

Technical Specification

After setting up SHM use in the Viz Artist scene and Field Linking in Ticker Wizard the vdf (Viz Data Model) look like this example:

<model
xmlns="http://www.vizrt.com/types">
<schema>
<fielddef name="locator">
<choice scope="suggest">
<collection src="source.xml" />
</choice>
<fielddef name="key" label="Shared memory base key" mediatype="application/vnd.vizrt.smmkey">
<fromatom select="locator" />
<value></value>
</fielddef> (...)
</schema>
</model>

The locator element can then be extracted from atom elements like this:

<entry>
<id>MSFT</id>
<published>2012-04-08T16:42:58+07:00</published>
<updated>2012-09-25T10:34:29Z</updated>
<title type="text">Microsoft</title>
<locator type='application/vnd.vizrt.smmkey'
xmlns='http://www.vizrt.com/atom-ext'>/stocks/random/MSFT
</locator>
</entry>

Note: Notice that namespace of the <locator /> element is the vizrt atom-ext and the type is application/vnd.vizrt.smmkey.


See Also