The Clip Input node is used to load media shot by movie cameras, and define the parameters of the clip and camera that are passed down the tracking tree for matchmoving.
Further information about the individual components of the Clip Input node are available in the Media Management section:
Source: The source media information. This is also where media can be loaded from disk.
Mask: The mask panel where media containing a pre-rendered mask can be loaded from disk.
RAW: The RAW panel where parameters for decoding RAW media image data can be adjusted.
Undistort: The Undistort panel where lens distortion correction parameters can be defined.
Metadata Viewer: The dynamic metadata viewer panel, showing metadata curves for any compatible metadata parameters.
Active Metadata: The active metadata window.
Camera Body: The camera body panel.
Camera Lens: The camera lens panel.