Force camera to change format

[GalHorowitz]

The usb webcam I use supports both yuyv and mjpg, the problem is, it's default is yuyv, and I need mjpg. So when use v4l2 camera it shows up as yuyv. The thing is, I found a solution. If I run fswebcam using -p mjpg, it manages to take a picture, and somehow now the camera changed state to mjpg (v4l2 now recognizes it correctly). So SOMEHOW there is a way to change the state. Could the library support it?