Unfortunately we are using a modified driver, which the test program does not work with. We needed to remove the necessity of individual camera drivers, so we control all of the things the sub-drivers work with custom V4L CTL commands.
However, I can tell you the BT656 is working perfectly fine with another camera we have. My current feeling is that it is due to the camera output frame size. The camera I am working with is 768x576 BT656 because it has square pixels as per https://www.intersil.com/content/dam/Intersil/documents/an97/an9728.pdf. Am I able to support this, or is it impossible?
Thanks, and sorry I couldn't be more helpful.