They do have a example code but they will not release it because they only use the example code to make sure they use the right registers of the stars micro-controller of the UVD unit.
In the end they will release only some spec with some register informations like the HDMI-Audio-case.
In this way they do have the highest chance to get a OK from the lawyers.
They tried it otherwise in the past and failed.
Don't be naive the HDMI-Audio was the test-run to get such a critical stuff out of the door.
For hardware informations spec there are lower regulations compared to software.
They can release critical informations 5 times faster if they only focus on critical hardware informations instead of hardware+complete software implementation.