Add support for Dolby Vision Profile 9 (MPEG-4 AVC Dolby Vision, backwards compatible with SDR)

[Hydra-Spectre]

I hope this can be added.
It would be a real boon for films and shows that are only 1080p Dolby Vision on streaming, and they have a Blu-ray release with higher bitrates.

[quietvoid]

Profile 9 is basically nonexistent in the real world, so it's unlikely to get supported.