Hmm... Do you think we could send raw serial data over USB? If we could, we'd be able to just push the image buffer over it and get 4:2:2 colour which would be bangin'.
You can implement a custom PTP message and do pretty much whatever you want, including sending a raw video frame.
So that means data can only be sent OUT of the camera, right?
What about feeding something to the camera?
Or, what can you do with the HDMI port?
The ptp protocol is bidirectional but from the USB point of view the camera is the device while the computer is the host.
I've never looked at the HDMI port bug i think it is handled by a separate chip