This issue is not about vMix, per se, but the machines involved in mixing and streaming.

I need to output Fullscreen HDMI to a separate streaming computer. The streaming machines are owned and maintained by HockeyTV. (formerly FASTHockey).

The capture cards on the HockeyTV machines are BlackMagic DeckLink Mini Recorders.

I am going Fullscreen through HDMI out from an NVIDIA GeForce GTX 1060 3GB.

The streaming machine runs encoding software that must work off of 720p at 59.94. So, I set the Display 2 resolution in the NVIDIA control panel to 720p.

The problem is that DeckLink doesn't recognize the output resolution. BlackMagic Desktop Video Utility reports the input as a 1080i60 signal. BlackMagic Media Express shows the video stream and similarly reports it at 1080i60.

I believe this is why the encoder software (proprietary), which will only work with a 720p signal, reports "DeckLink No Video Signal".

NVIDIA support suggested that "NVIDIA graphics cards work on EDID, which is a data structure provided by a digital display to describe its capabilities to a video source. The EDID of this NVIDIA hardware reads as 1080i rather than 720p," and suggested that I try to find out "if BlackMagic supports EDID." I learned today that starting with v3.4 BlackMagic has implemented auto-detect.

I am able to connect an HDMI camera and an HDMI media player both set to 720p directly into the DeckLink, with Desktop Video Utility reporting the correct resolution, and have the signal successfully connect to the encoder software.

I am able connect a Mac Mini (AMD Radeon HD) set to 720p resolution to the DeckLink, with Desktop Video Utility reporting the correct resolution.

I cannot connect the vMix machine out through the NVIDIA card in through the DeckLink card to the streaming machine at 720p..

Thanks for any help.