Problem (symptoms): When Isadora opens the Blackmagic driver the device is forced into YUV 4:2:2 input mode, producing a black preview even though the incoming HDMI signal is present at 1080p60 RGB 10‑bit. Launching Blackmagic Media Express immediately reconfigures the device to RGB10 and the image returns.

Possible root cause: Isadora is calling the Desktop Video API without negotiating or selecting the correct pixel format/display mode (or is explicitly requesting a YUV pixel format). The Blackmagic driver will accept an explicit RGB10 request or perform auto‑negotiation if asked; currently Isadora’s call path forces YUV.

Recommended fix 

1. Negotiate display mode + pixel format on open — call the Desktop Video API to enumerate supported display modes (GetDisplayModeIterator / display mode list) and choose the exact 1080p60 mode reported by the device.
2. Request RGB10 explicitly when available — call EnableVideoInput (or equivalent) with the matching display mode and bmdFormat10BitRGB (or the SDK constant for 10‑bit RGB).
3. Expose a UI override — add a simple capture setting: Pixel Format: Auto / Force RGB10/ Force RGB8/ Force YUV422 for troubleshooting and edge cases.