Mewa Film User's Guide/Nodes Reference/Footage node
About the Footage node 
The footage node is the starting node of any image processing operations. It represents a clip (sequence of frames) and it outputs an image for each different time.
To use the footage node, or any other image node, with 3D nodes you can use the ImagePlane node which represents a image as a plane in the 3D space.
Add footage to the node graph 
Adding footage nodes to the node graph is done differently than adding other nodes, ... are a special case of nodes because each footage node have an entry in the timeline.
To add a footage node to the node graph you need to have Footage window opened. Footage nodes are created by dragging the chosen footage from Footage window to the node graph window.
Another way of adding footage to the node graph is selecting the footage from the Footage window and click (pic).
When adding a Footage node to the node graph a bar is also added to the timeline. This bar represents the footage length (or duration) in time. For each Footage node in the Node Graph an associated bar in the Timeline is created. This means you can have several footage nodes, all referencing the same footage name and all with different timings.
The stating frame of a Footage node can be shifted in time moving the timeline bar back and forward. The footage node can be trimmed and extended. More about the timeline can be found in Using the Timeline chapter.
This means that footage can be replaced any time of the development of a project and preserve its start and end time, chosen on the timeline. e.g add one frame footage to the node graph, extend it to a desired size, and at a later stage of the project replace that one frame footage with a bigger one.
You can have more than one footage node pointing to the same footage.