Streamline Your Portable Streaming System, Part 1: Streaming Software, Capture Cards, and Signal Converters

Capture Hardware

I’ll focus on two four-input capture cards used in the various streaming systems we employ. One of them is the Matrox VS4 (Figure 6, below). The Matrox VS4 provides four-channel HD-SDI inputs and is compatible with both the Wirecast and vMix software. In addition, Matrox has introduced a software app called Pro Recorder that allows you to record 4 individual ISOs and save them in various bit rates to archive some of the footage you’re capturing at a multi-camera switched shoot if you need archived versions of the individual camera streams.

Figure 6. The Matrox VS4

Another card we use is the Blackmagic DeckLink Quad (Figure 7, below). Unlike the PC-only VS4, the DeckLink Quad is both Mac and PC-compatible. It can’t record ISOs like the VS4, but it functions fantastically as a switcher and also has various other capabilities that are adequate for streaming.

Figure 7. Blackmagic DeckLink Quad

Those are the two cards I recommend in building your own streaming system, or as built-in components of various pre-built streaming solutions. When purchasing a streaming system, be sure to consider whether or not the functionality of the card it incorporates serves your purpose.

Converter Boxes

Converter boxes are one of the better-kept secrets in the streaming world, but you will at some point discover that you can’t get through a shoot without one. The biggest and most common challenges that streaming producers face are Internet and bandwidth issues. But a close second are scaling issues you encounter when recording and streaming presentations presentations. Presenters generally tend to want to bring their own laptops to deliver their Powerpoints at a corporate or conference event. You don't know what they're going to be feeding you; it might be VGA, or it might S-VHS or some other ancient technology. Whatever the source, you’ll need to scale it immediately to get it into your stream, and for this you’ll need a versatile converter box.

Fortunately, The Roland VC1-SC up-down cross-scan converter (Figure 8, below) has been a lifesaver for us at some events. It can take various inputs from 3G, HD-SDI, HDMI, and composite sources. It can handle pretty much anything you throw at it. It allows you to take that feed and convert it to a compatible signal to bring into your switcher. I highly recommend looking into the VC1-SC because it can handle various inputs and give you the output that you need.

Figure 8. The Roland VC1-SC converter

Another option is Blackmagic Design’s HDMI-to-SDI Mini-Converter (Figure 9, below). Blackmagic also offers SDI-to-HDMI converters. It’s good to have a variety of converters in your bag because you never know what type of input you’ll have to deal with on a given day.

Figure 9. The Blackmagic HDMI-to-SDI Mini-Converter

There are some drawbacks to the Blackmagic converters. In my experience, they can be very finicky in the type of signal that you're sending to it and getting from it. Blackmagic tends to like 1080i 59.94.

Atomos, best-known for field recorder/monitors like the Ninja and Samurai, offers two converters: the Connect S2H (Figure 10, below), which converts HD-SDI to HDMI; and the Connect H2S, converts HDMI to HD-SDI. They function like the other converter boxes discussed above, but the great thing about the Atomos units is that they're battery-powered, and they're also quite versatile in the different scan rates they support. They’re also very compact; as illustrated in Figure 7, they can fit them in the palm of your hand. (The Blackmagic converters can also run on batteries but they’re not as compact as the Atomos models.) Both Atomos converters run on both battery and AC power.

Figure 10. The Atomos Connect S2H HD-SDI to HDMI converter

Again, one particular converter may not work for you when you’re on location. So I recommend buying multiple converters. They're all relatively small and somewhat inexpensive, but they can save your entire stream at crunch time.
In Part 2 of this series, we’ll look at cameras for HD and 4K production.