Playing video files

In 99% of the cases you will work with Video or Multi-layer stock layer templates when playing back video files.

If you double click on one of those layers you will find that there is a Play video node in both of these layer templates. This is the node that actually takes care of the video playback.

You will also notice that the inputs of this node correspond to the exposed Layer variables described in Video layer template page.

Content framerate

To understand framerates in video playback in LightAct we need to understand the differences between Content framerate, Project framerate and Application framerate. Content Framerate is the framerate of the Video asset, whereas Project framerate and Application framerate are explained here.

In order to prevent any missed frames, Application framerate should always be higher or equal to the Project framerate. Project framerate should in most cases be the same as the Content framerate, but never lower. Sometimes it can be 2 times higher.

If Application framerate drops below Content framerate, you will get missed frames.

When LightAct executes (triggers) a Play Video node, it always passes the time of the frame it wants to get. This time is determined by the progression of the playhead across the timeline which is determined by the Project framerate.

This means for example:

• if Project framerate and Content framerate are both 30 and Application framerate is a steady 60, LightAct will request and display each frame twice.

• if Content framerate is 30 and Project framerate and Application framerate are both 60, it also means that each frame will be requested twice. However, if you have Frameblending enabled, you will get 2 frames blended every second frame.