To see properly what the contents of a NUV file were, I decided to implement a scan program. This would allow me to analyze the structure of MythTV's output and also see the timing information. And as the NUV parsing code is required for nuv2avi anyways, it was a good trial run.
The output of nuvscan is very verbose. This is to be expected as it dumps detail for every frame in the file, including closed captioning dumps. At a future time, I will likely make it selectable just what details to display, but for now it will just spew.
To add later: