There are some amd cards out there which do their hw decoding with shaders -> those lengthy list crashes the kernel when doing hw decoding -> list could be found.

Intel: VC1 interlaced is implemented to just assert(0) - but it's only the interlaced VC1. So in order to playback VC-1 progressive we need to have such an option - as you know about how VC1 format is defined and can change interlace / deinterlace on the fly -> option needed.

Nvidia is fine, so users should not care -> therefore hidden.