FairPlay 1.x/4.x content either shows a black screen or crashes

[VisualEhrmanntraut]

Describe the bug
AppleGVA (Hardware decoding/encoding) using VCN works on Navi 22 but not DRM; you usually just get audio but no video.

To Reproduce
Steps to reproduce the behavior:

1. Try DRM playback
2. See error or video but no audio

Expected behaviour
The DRM video to play normally.

[ExtremeXT]

Fairplay 2.x/3.x based hardware DRM content seems to be playing just fine, only Fairplay 1.x (QuickTime DRM), Fairplay 4.x (a mix of all previous Fairplay versions) (Apple TV, Apple Music Bluetooth / Loseless) seems to be broken. Might be related to HDCP.

[Doghouse-Mike]

Not sure if it helps, but I noticed Netflix (via Firefox) would do the black screen with audio when I also had another device connected to the "Mac" via vnc. Displays video fine when no VNC shenanigans are going on.

[VisualEhrmanntraut]

Yes, it's similar to NootedRed's behaviour where the audio plays but the video is black.