Tutorial: How to Use vMix 4K Virtual Inputs to Deliver a Multicam HD Stream from One 4K Camera

While some video producers prefer individual products for individual functions, I have found in my own video production business that I need to maintain several combinations of solutions depending on the production requirements and, often more importantly, the smallest-sized solution that I can travel with. On my more complicated productions, I prefer to work with my mobile production studio, a custom-designed studio cart with rackmounted components and either a laptop or a workstation loaded with the vMix switching, recording, and streaming solution.

This approach isn’t too dissimilar from a traditional studio installation except that my mobile production studio transforms from a large black ATA-style box on casters to a full mobile production studio. Because of its flexible rackmount design, this mobile studio can be customized further by adding or removing components, according to the needs of a specific production (Figure 1, below).

Figure 1. Shawn Lam Video’s new Mobile Video Switching and Webcast Studio

This ability to preconfigure all the complicated connections and signal flows in advance saves valuable setup time on location. The front lid of the mobile studio even converts into a matching side table. Despite all the high-tech gadgetry crammed into the actual production studio, the convertible lid/table is one of the elements that impresses clients and attendees alike. (This is important when you are front-of-house and not hidden backstage.) After 15 years of producing live events professionally, I have found that it is important both to produce a great product but to also look like your equipment is worth the rate you are charging.

On my smaller productions, I could be filming with a single camera and audio feed, live switching with a computer presentation, and live streaming the program to an online audience. For these productions, I can limit my equipment to a video camera, audio/microphone input, HDMI- or SDI-to-USB 3.0 or Thunderbolt external video capture hardware, and a laptop loaded with vMix. After the live event, I can quickly make a few edits to the vMix-recorded program and upgrade the live version with a higher bitrate, on-demand final version.

When 'Mobile' Isn’t Compact Enough

It’s easy to determine when to use these two different right-sized solutions, but what isn’t so obvious is what to do when I want the power of my mobile production studio but the location’s limitations restrict where I can use it. The week I wrote this article, I had two productions that had no elevator access to my production location. I didn’t want to attempt to lift my mobile production studio up two to three flights of stairs because of its size and weight (as well as the consequences if someone got caught under it). In both cases, I opted for a smaller standalone video switcher, the Roland V-1SDI, and paired it with vMix to add graphics, internal recording, and streaming. In Figure 2 (below), the reverse-angle camera on input 3 is being wirelessly transmitted by the Paralinx Triton, and the channel 4 input is the actual webcast fed back into the video switcher so I can monitor it, along with the three live inputs on the Multiview monitor.

Figure 2. Webcasting a three-camera live switch using the Roland V-1HD for mixing and vMix for webcasting and recording. Click the image to see it at full size.

Although in each of these scenarios my workflow might be completely different, what remains constant is that vMix is an integral part of almost all of my live-switch and webcast workflows, which I broadcast to a channel or website via embed, using my Ustream Enterprise account. The only exception is when one specific client has me use its Livestream account for the webcasting. This doesn’t affect my normal workflows, but it might be important to you if you use Livestream or are considering using Livestream for webcasting. I cannot webcast directly to Livestream from vMix. For this workflow, I use Livestream Producer instead.

As with other software-based switch-stream-record software solutions, with vMix you can connect multiple external audio and video inputs to your laptop or desktop/workstation computer (Figure 3, below). Video capture cards compatible with vMix include internally mounted PCIe cards for desktop/workstations and external USB 3.0 or Thunderbolt video capture hardware that are popular on laptops and all-in-one computers. Some hardware can support up to four camera inputs on a single hardware card, while others are limited to a single HD or even 4K video input.

Figure 3. Adding camera inputs to vMix is as simple as selecting the appropriate camera, input, resolution, and frame rate in vMix’s Input Select Menu.

Audio can come into vMix via embedded audio on any of the video channels or a variety of dedicated audio input options such as audio capture cards (on-board or add-on) or over USB via a supported soundboard or capture device. I consider these audio and video inputs to be traditional inputs, similar to what you would expect in a hardware video switcher.