Case Study: Mobile, iOS-based, Live-Switched Streaming

In this article, I’ll walk you through my completely mobile, iOS-driven, multi-camera, wireless live-streaming setup. It was designed around the need to push multiple live streams at an outdoor event where I needed to move everything around with me all day long. There was no AC or ethernet feed. Everything I used was mounted on two tripods.

You could easily adapt this to do a multi-camera production in a car, a boat, or any other place where you need the flexibility and production value that a switched production delivers, but still need it to be completely mobile.

For this shoot, I was at the Frisco Art Walk in Texas, doing a series of Facebook Live streams for the Frisco Association for the Arts. I had three cameras. In the video that accompanies this article, I do a visual walk through the gear I had with me and I used one of the cameras in the live-streaming kit because it was already set up for recording

The Kit

The camera I used in the video to show off the entire setup (Figure 1, below) is an iPhone 5 with an accessory wide-angle lens. I chose the 5 because I personally like the form factor of the 5 with the flat sides. Plus, accessories I purchase for the iPhone 5 will also work with the iPhone SE, which is nearly identical to the iPhone 5 and is actually still a current and very affordable Apple product, despite the years in between (iPhone models 6, 7, 8, X). The iPhone 5s has also been included with the upgrade to iOS 11. The iPhone 5 has been orphaned with iOS 10.

Figure 1. The mobile streaming setup used at the Frisco Art Walk

I have two cases for the iPhone 5. One is a “glove”-type case that fits tightly, and has a metal mount for external lenses. It does not have any mounts for accessories or tripods, but the case is only a millimeter bigger than the phone so it fits into any generic phone holder clamp. For the video I have a wide-angle lens on the camera that came as part of the kit. In the description of the video on YouTube, I have links to the items that I used.

I have a second iPhone 5. It may be a 5s; to be honest, I can’t tell the difference between them. This second iPhone 5 is housed in an iOgrapher case. These are very common and also very handy in that they have handles to facilitate walking around with the phone without fumbling. There are also cold shoe mounts on top for microphones and lights. The iOgrapher has a wide, flat base with a 1/4-20 threaded hole for tripod mounting. On the front, there’s a large threaded mount for lenses. iOgrapher offers a wide lens, a telephoto, and a long-range zoom.

I have an iPad Air, again with an iOgrapher case (Figure 2, below). There’s really little you can do in terms of mounting an iPad with accessories. I think the iOgrapher is a little pricey for stamped plastic, but then again, it's still considerably cheaper than other solutions on the market. It also does what it’s designed to do with no fuss. I like the one I have because it’s flat, which makes it easy to slide into a laptop case.

Figure 2. The iPad Air in the iOgrapher case

Every time Apple makes the slightest change in the design of its devices—a millimeter longer, wider, thicker or thinner, rounder, more square, moves the buttons a little, or moves the camera a smidge—the existing cases don’t work and entirely new products need to be designed and molded for the new iOS device. There are products available that are designed for “generic” tablets, intended for tripod-mounting, hand-holding, and accessory-mounting, but those are even more expensive, and considerably bulkier.

Without some sort of “encasement” there’s really no clean, reliable, or easy way to mount accessories onto the iPad, or to mount the iPad onto a tripod or other support. If you only want to use an iPad for control, then you can use a table-top “folio,” but then you also lose the potential use of one of your cameras.

For audio, I’ve investigated ingesting audio into the iPad via USB, and via a TRRS cable. This TRRS (tip, ring, ring, sleeve) cable has the additional ring where the microphone from a headset is fed back into the iOS or Android device (Figure 3, below). When I’ve done head-to-head tests between USB audio and analog audio, the USB audio was cleaner and better sounding—by far.

Figure 3. This TRRS audio cable is iDevice ready, but doesn’t fare well in head-to-head tests against USB audio.

However, my USB audio mixer is bigger, it requires AC, and it uses a sizeable and heavy AC adapter. So I scoured the web and found the tiny USB audio mixer shown below the iOgrapher-mounted iPad in Figure 1, which touted that it could not only export audio over USB, but that it had the ability to be powered by USB as well. This Maker Hart Just Mixer 5 is a cool little device but, unfortunately, the USB audio is not recognized by iOS devices. I contacted Maker Hart about the issue. The staff said its mixer is designed for line-level audio out, and the iOS device wants microphone-level input. So apparently the two devices communicate, see the discrepancy, and do not pass audio at all, even though I could just turn down the master out and make it work.

Nevertheless, the small form factor of this lightweight mixer is still desirable. Its small, external USB battery pack was downright diminutive compared to the AC adapter for my bigger mixer. The Maker Hart mixer also has Bluetooth audio in on channel one, meaning it enabled me to eliminate at least one cable in the audio mixing. I was able to play some intro and outro music from an old iPhone 4 over Bluetooth into the mixer. I set it on one track, told it to loop, and it just did that all afternoon.

Also feeding the audio mixer was my host’s wireless handheld microphone on input 2. I had a second wireless lav set up on channel 3, in case we needed a backup, or two people on camera with mics. But primarily, I planned on having the host point his handheld mic at the guest and manage the audio that way. Lastly, on channel 4, I added a powered short shotgun microphone (Sennheiser) mounted on the iPad that you can see in Figure 2 as a backup for ambient sound, or in case everything else had issues.

The output of the mixer goes into a special cable that feeds the TRRS of the iPad. I tried a cheap little adapter with two 1/8" sockets for headphone and microphone, but it was hit or miss with that adapter. A more expensive adapter always worked reliably, but it had a 15' cable which I wrapped around the handle of the iOgrapher case. The cable adapter also has a headphone jack so I can hear what the application hears, but it's delayed by something like a half second so I cannot keep my headphones in while doing my own audio into the app.

The mixer features sunken sliders for each of the inputs (I used four of the five available), which makes it hard to bump them. It’s also designed to ensure that when you throw the mixer into your gear bag, you’re not going to break the sliders off. There are also sunken “bass/treble” controls. Honestly, these are sort of a weak point of the mixer as it's little more than a "tone" control. You can turn it counterclockwise to reduce treble, or you can turn it clockwise to reduce bass (useful for wind noise). But you are not increasing any part of the original signal. It's essentially a adjustable bandpass filter on a dial.

The outputs include 1/8" stereo as well as L/R RCA jacks that use a common Master output slider, and a headphone jack with its own adjustment dial. There is also USB audio out which I have not tested as it does not work with iOS. The fact that it offers stereo outs from each input would benefit from a “pan” control on each input, but this mixer does not have any pan control. Thankfully, I did not have any issue with a microphone not appearing in the audio channel that was fed to the iPad.