camera images coming from Other source

I am new to Vuforia. I want to integrate One of my device that has prebuilt camera. From that device i can get image frame and other parameter that required for AR. I can use that device camera as " android.hardware.usb".

I want to implement AR Using that Device Camera(External Camera) or using the frame of Device Camera to add AR feature to  that frame.

Problem:

I try vuforia documentation for  External Camera I am not able to find How I can do that.

If any one now plz help me to configure external  Camera or external frame.