Capturing and Save Live Camera Feed In Unity

I want to display the video using the device camera on specific part of the screen on iOS, android and Editor. I was able to find the WebCamTexture which display the camera video on the Quad (3D Object). Now I want to record the video and save it on the disk. Is there are way to do that ? Or is there a better way to do that using unity or through plugin ?

As far as I know, this answer is still correct.