V4L2 - Error in setting apture format

I am using the DM365EVM to capture PAL video, add pixel information on the left edge and play it out again in PAL format (to be stored on a dvd recorder for now, maybe will save the digital data soon).  When I run up a butchered (mostly debug stuff added for myself) fbdev_loopback program with video connected from a Video Pattern Generator it all goes fine but when I connect a black&white camera that probably doesn't have a video signal that is 100% on spec, the driver kicks me out with an error "Failed to initialize capture" when it does the IOCTL on VIDIOC_S_INPUT. In the encodedecode demo I was able to change the application to force the capture of PAL composite signal sucessfully and start my application with my dodgy camera but now using the v4l2 drivers I need some help to once again force the capture input to take what it gets as we have lots of different - all black&white- cameras with varying outputs but probably/hopefully close to the PAL standard.  The VPFE capture driver - sprugp6 - is a bit cryptic describing precisely what happens between enumerating the input types, selecting the/a type and setting it with VIDIOC_S_INPUT.