SPX renderer

How does SPX generate graphics output

SPX has two options for playing out graphics: Web render and CasparCG.

CasparCG workflow

CasparCG server can output video to HDMI, SDI, NDI and more and it has a HTML producer, capable of rendering HTML-based graphics templates. 

When using the CasparCG workflow, SPX will use AMCP protocol to send commands from SPX to CasparCG server(s) which will load individual HTML templates to specified servers > channels > layers. 

This enables flexible mixing of video and graphics-based content onto several layers.

By default, the SPX configuration does not have any CasparCG servers available. Once servers are added to the configuration, they will be shown at the top of the SPX user interface.

Each server connection is indicated with GREEN (connected) or RED (disconnected) colors. Additionally sending of commands to each server can be toggled momentarily on or off for testing purposes in production environment. 

Please note: The server name "OVERLAY" is SPX's default server name in the templates.

See Adding CasparCG servers.

Alternative CasparCG workflow

It is possible to load the SPX web renderer to the CasparCG server channel and layer using AMCP commands.

Please note the actual syntax may vary between CasparCG server versions, the below example works in version 2.3 and newer:

With this workflow, all the 20 SPX layers will be present in a single CasparCG layer. This can be useful for instance when setting up CasparCG-based previews. See below for details.

Web render workflow

Web renderer is the HTML-based renderer output from SPX that supports up to 20 layers of simultaneous graphics using a single renderer URL.

The typical output from SPX is in http://localhost:5656/renderer

This output URL will be added to a vision mixer or streaming applications "browser source" settings.

The following parameters are supported


A combined full url can be for example:

These parameters can allow for very complex production workflows having multiple outputs of different sizes and aspect ratios.

In SPX configuration a default output resolution is set to either HD or 4K. 

PLEASE NOTE: Typical SPX templates are designed for 16:9 aspect ratio and responsiveness issues must be resolved on template-by-template basis. 

No frame accuracy!

Expectation management.

Since the SPX graphics output is based on loading HTML templates and additional assets, such as images, CSS files, and javascript libraries from local and potentially online sources (using a variety of computer hardware and software) the loading times of each template can vary and SPX is not intended for workflows requiring frame-accurate playout!

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