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

Advanced Input Options

Now I introduce some of the advanced input capabilities within vMix that extend its capabilities beyond that of a traditional video switcher.

Additional external audio and video options include pairing vMix with a Teradek Cube (Figure 4, below). I use my Cube normally for mobile webcasting straight from my video camera, but it can also transmit HD video over a wireless or wired network to a connected vMix computer. Using a Cube in this workflow means that you don’t need a video capture card on the vMix end, which is an important consideration when you have limited video capture cards on your PC or laptop. To pair the Teradek Cube with vMix, connect both devices on the same Gigabit network. Then configure the Cube to send an RTSP stream from your connected video camera. In vMix, you then input the RTSP URL as a new Stream Input.

Figure 4. The Teradek Cube paired with vMix. Click the image to see it at full size.

Another similar network-based video input method is to use the NewTek-designed NDI protocol to send video from one computer to your vMix computer. The NDI option requires a computer installation and running the vMix software. For best results, the two computers should be connected over Gigabit Ethernet. This network connection is an important workflow consideration. Although you can use NDI over a hotel internet connection, this may be problematic if the presenter’s computer is on a Wi-Fi connection and you are on a different network with an Ethernet connection. You can add a second Ethernet connection from the presenter’s laptop directly to your vMix computer with an inexpensive Ethernet-to-USB 3.0 adapter that supports Gigabit Ethernet.

NDI is a great option for capturing a computer presentation without having to deal with splitting a VGA or HDMI signal from the presenter’s laptop, sending one feed to the projector, and converting the other to SDI, in order to run a cable long enough to connect with the video capture hardware on your computer running vMix. Another creative utilization of NDI on vMix is to connect two vMix computers to add additional video inputs. This workflow is useful when you are running vMix on a laptop that may have a limited number of USB 3.0 busses and you want to add additional external hardware inputs.

After you install the vMix Desktop Capture software or another instance of vMix on a remote computer, and connect it to the same Gigabit network, you can add that computer’s outputs as inputs on your vMix software. The Desktop Capture software is great for sharing computer presentations, while running vMix on the remote computer allows you additional and multiple send options, including all the audio and video devices connected to the remote computer. The NDI/Desktop Capture selection (Figure 5, below) allows you to see which inputs are available as sources on your vMix system and which outputs you are sending to the remote vMix computer.

Figure 5. The NDI/Desktop Capture interface. Click the image to see it at full size.

With vMix, you can also load in all the slides, videos, audio, and graphics for which you have hard drive space on your computer. The caveat is that complicated PowerPoint presentations with builds and transitions will appear only as the final step in the slide build. So always test PowerPoint slides in advance.

As general rule of thumb, vMix will see a PowerPoint slide exactly how a printer would see the same presentation’s handouts. This means embedded video and audio should be stripped from the PowerPoint presentation before you import it into vMix. It is then added to vMix as a standalone video or audio file that you can switch to at the appropriate time. Of course, this applies only if you are replicating what a presenter is showing on a nonconnected system. If you use NDI to connect the presentation, then whatever is being shown and heard from the presenter computer can come into vMix as an NDI input.

I often find when there are multiple presenters at a conference, some of whom may arrive just before their presentation, they will often ask to use their own laptops. As a result, the ability for you to push slides and audio/video files for your purposes gives you additional flexibility when a presenter throws you a curveball after you have already started producing a live switch.