Output management

To ensure smooth playback of content, there are several steps that we recommend:

1. Please make sure you understand how LightAct manages vertical sync across the displays connected to the server. This is explained in the chapter below.

2. Use fixed EDIDs wherever possible.

3. Use Mosaic wherever possible.

Framerate and vertical sync management

How LightAct ensures that the playback is smooth and how it manages the framerate can be summarised in these 2 rules:

1. when there are no outputs enabled, it is locked (vertically synced) to its UI display.

2. as soon as you enable one output, LightAct releases the vsync to its UI display and enables vsync to the output display.

Good to know: The purpose of syncing LightAct's refresh cycle with the output display's refresh rate through the vertical sync mechanism prevents playback stuttering.

This is done automatically and there is no additional action on your part required.

Good to know: if you want to manually adjust vertical sync settings, you can do that by:

1. enabling Remote support in the General tab of the Preferences window.

2. Adjust Vertical sync dropdown in the General tab of Project settings window.

EDID Management

EDID (Extended Display Identification Data) is a metadata standard for display devices such as monitors, projectors or video splitters to communicate their capabilities to a video source, which is in LightAct's case of course the GPU. This includes the display size, video input type, color characteristics, pixel mapping data, various timings and so on. This information is transmitted from the display to the GPU the moment you connect it and it allows the GPU to then send out a video signal that is supported by the display.

In professional AV it is recommended for the video source to read this information from a file instead of from the display itself. For example, switchers and cable extenders can cause the display EDID to be lost. With the EDID being read from a file instead of a device, the OS will always assume the display is attached. This way of managing EDIDs also provides protection against hot plug events which often times lead to reconfiguration of your displays.

Good to know: loading EDID from a file is also called using a Fixed EDID.In Pro AV it is usually recommended to use fixed EDID

There are 2 ways to manage EDID:

EDID Management in LightActEDID Management with Nvidia Control Panel

Multiple outputs

If a machine has multiple outputs we strongly recommend to combine them into an Nvidia Mosaic. This is the best way to ensure that they are perfectly in sync and that there is no stuttering on the outputs.

Nvidia Mosaic

NVIDIA Mosaic Technology uses NVIDIA Quadro cards to take multiple displays and present them as a single logical GPU to the operating system. Mosaic technology lets you use multiple displays to create a larger, virtual canvas with minimal performance impact on 2D or 3D applications such as LightAct. This includes no application software changes or visual artifacts.

In our case, we would like to keep our UI display separate and create a Mosaic which will include all of our Output displays.

Set up MosaicModify or Disable Mosaic

At the moment, to enable a Mosaic, you'd need to use NVidia Control Panel.

Not using Mosaic

We do not recommend not setting up an Nvidia Mosaic, however if for some reason you are unable to establish it we recommend that:

• all the outputs need to have the same refresh rate

• sync them using a Quadro Sync card (Sync Expansion Module)

If you cannot or don't want to enable a Mosaic, all the outputs need to have the same refresh rate.

To learn how to set up a Mosaic, click on the link below: