A media server is a key step in the on-set virtual production (OSVP) pipeline, sending assets like background plates, LUTs, and tracking data over a network so that they can be used to create unique real time in-camera virtual effects (ICVFX). Whether it be a rendered set from Unreal Engine or an uncompressed prerecorded background plate, the media server is what stores and transmits these virtual pieces to the LED walls and processors. Let's dive deeper into what these servers do.
What's Important in a Media Server?
Media servers for virtual production must be capable of real time playback and distribution, often utilizing NVMe arrays to store and call up super high-resolution media and assets then send them across high-speed networks. The server typically needs enough space to store large builds from virtual environment programs like Unreal Engine, 3D assets that are used in these builds (think textures and meshes), background plates, LUTs, graphics, masking data, tracking data, and more. The server often utilizes 10GbE to 100GbE (Gigabit Ethernet) speeds to be able to share this information frame by frame with computers, cameras, and processors in the private network, plus receive tracking information back.
Hardware vs. Software Servers
Hardware servers typically come in the form of custom-built server racks from brands like Disguise and Puget Systems. These are ready-to-roll from the jump, with all the inputs and outputs you need, as well as VP-specific features like upgraded cooling and redundant power supplies.
Software-based solutions like Assimilate and PIXERA can run from a custom or off-the-shelf computer, but often require a license or subscription, and a little more work to get the pipeline running smoothly. If you have the money and see yourself sticking with the same set-up for at least five years, go hardware. If you're looking to save a bit and see yourself possibly growing your set-up in the near future, start with software.
Or Use Both!
Larger OSVP workflows will typically use hardware servers for routing and playback alongside software servers for rendering specific assets like Unreal Engine backdrops. All of these tasks are incredibly CPU-intensive, so splitting the load between multiple servers can be necessary even in smaller virtual production scenarios, especially if you're utilizing multiple cameras. Professional server options like Live FX can also handle a wider range of media types including raw video. Higher-end features like ghost-frame and live masking are even more CPU-demanding, especially if one server is feeding multiple LED processors.
What to Watch Out for with Servers!
Media servers are doing the real-time synchronization between the virtual background and the in-camera footage, so real-time feedback and genlocked video is a must. Don't skimp on your server or you'll see virtual backgrounds stutter, tear, and fall out of sync. Some media servers are built for live events and can't handle the more complex use cases of OSVP, so look into the specs of your server's specific render nodes. Ideally each will pack a punch with a modern CPU, GPU, Sync Card, ample RAM, and fast NVMe storage. Some LED panels work best with certain media servers, so be sure to also check with your panel manufacturer for guidance.
If you'd like to learn more about Virtual Production, check out our other guides and articles on the B&H Explora page!
