I think this thread’s about as far as anyone has gotten. Some carrier board manufacturers can make analog video inputs, I think Auvidea is one of them.
Our company, AVerMedia Technologies, Inc., specializes in frame grabbers solutions. If you can accept frame grabber in your application, you might use one of the following 2 products to capture NTSC/PAL video. We have verified they work for both TX1 and TK1.