In general, Casablanca can use any external camera source (e.g. webcam) as input that is also recognized as an acceptable camera source by common video conferencing programs. However, at the current stage of development, Casablanca is not designed to correct eye contact and head orientation for previously recorded videos via emulator programs and machines or similar.
If your program or external source does not work with Casablanca, your case is unfortunately not supported yet. However, we are constantly working to ensure Casablanca's compatibility for an even wider range of inputs and to develop workarounds if necessary.