We use vMix for our live productions. It's a powerful software switcher that allows us to produce high-quality live streams and recordings. We use it in conjunction with Blackmagic URSA and Studio cameras, and we wanted to be able to control the tally lights on the cameras from vMix.
There is not a native way to send tally data from vMix to the Blackmagic cameras, so we developed a solution that bridges the gap.
vMix uses TCP to communicate tally data, while the Blackmagic send tally and CCU data back on the return feed to the cameras va SDI (meta data is on audio channel 15 & 16).
Blackmagic needed a way for developers like us to be able to manipulate the camera control data, so they developed the Blackmagic 3G‑SDI Shield for Arduino. The shield has an SDI in and out, and allows you to manipulate the camera control data in real time. We developed a solution that uses the shield to send tally data to the cameras based on the TCP data from vMix.
It is unfortunate that the Blackmagic shield is required at all--the new studio cameras do have some native network support, so we think this may be a stop-gap solution. Thei shield itself is limited to 3G SDI, so that can be problem with 4k workflows. The shield also comes unassembled, so you will need to do some soldering to get it working.
The upside is that it works really well, and it's a very cost-effective solution to leverage your existing studio viewfinders and tally lights built-into your Blackmagic cameras. We are using it in our studio every day, and it has been reliable.
We've got some plans to improve the management interface and adding some other features, but We are excited to share our v1 solution with the community, and we hope that Blackmagic will continue to provide developer-friendly interfaces to their cameras.
More information about building your kit, and source code download is available on Gitbub page for the vmix-blackmagic-tally Github page.
Let us know if you're using it in the wild, and don't hesitate to reach out on Github if you have any issues or feature requests.
