OptionaldeviceOptionalfacinga facing or an array of facings which are acceptable and/or required.
OptionalframeA ConstrainDouble specifying the frame rate or range of frame rates which are acceptable and/or required.
Optionalprocessorinitialize the track with a given processor
Optionalresolution
A ConstrainDOMString object specifying a device ID or an array of device IDs which are acceptable and/or required.