Yes this is possible. You an use the AN75779 app not firmware example and comment/remove the contents of sensor.c/.h file. You can stream 720p resolution and connect 12-bit of data to the GPIF data lines, FV and LV signals with your source of video data. As you pointed out, you will not see a proper/clear image as your sensor gives 12-bit data and you will send it over 16-bit per pixel. You may need to do some image processing on the Host to see clear images.