iOS Multicam Streaming and Recording Video Quality Showdown

The Ugly

That was the good and the bad. Now for the ugly.

The ugly part is heavy compression. This is, of course, a fact of life, because we’re taking an HD signal which is often recorded in camcorders and DSLRs at 50 or 100Mbps before we smoosh the life out of it to get it to 2-4 Mbps for a 720p30 stream. On my DSLR, I thought 24Mbps AVCHD was way too little. Now I’m producing content with a fraction of that.

So, in terms of producing the highest quality image possible, typically this means using better cameras. With Teradek and Cinamaker, you can use any HDMI source you want. In the test video that accompanies this article, I use a Panasonic DMC-GH4, and you can see that the quality difference is huge compared to the iPhones, even at 4 Mbps. A better camera is the best improvement you can make.

But iPhones themselves are getting better, and the latest-generation iPhones look far better than the test subjects in the video, the iPhone SE (which has the camera and processing from the iPhone 6s). So it uses several-year-old technology. However, this is not a camera test; it’s a processing and recording test. Holding the playing field level with the iPhone SE, we’ll see which iOS app can deliver the best video. Get a newer phone and you’ll improve the video, of course, but I’m testing which app will get the most out of whatever device you have.

The Tests I Ran

The first test I did was for average streaming data rates of about 4Mbps. I had to move the data rate around because the three apps don’t use the same data rate numbers. So it was 4 to 4, or 3.2 to 3, etc.—as close as I could get it to a typical 720p30 streaming data rate.

The second test was to determine which app was best when fully maxed out. First I set each app to its highest resolution: 1080p for Teradek (Figure 4, below) and Cinamaker, 720p for Switcher Studio. In terms of bitrate, Teradek offers up to 10 Mbps. Cinamaker's “Best” setting is around 12Mps. Switcher Studio peaks at 6Mbps.

Figure 4. Teradek data rates

In the video, I stayed with a 720p timeline as a lot of streaming is done at 720p. In particular, most Facebook live streaming is limited to 720p. If you produce at 1080, Facebook will downsample the 1080p you send there. YouTube and other outlets will easily stream 1080p or higher. So having the capability to do higher resolution streaming is good.

Moreover, if you are recording, not really limited by upload-speed limitations, and you have a wireless router capable of moving a lot of data, or are putting the cameras on ethernet, then using a higher data rate is not an issue at all, unless you need to record all day long into the iPad. But recording one master program is much less data to manage and offload than if you tried ISO-recording each device. ISOs are nice as backups, but many times, you’re going to edit from the master recording anyway, so it’s easy to trim or cover any potential mistake in the live switch.

Audio Issues

Audio is the other half—and, some argue, the more important half—of the video. If you have glitchy video, people will probably stick around if the content is good. If you have bad audio, they’re gone. Good audio can carry a poor image, but bad audio won’t carry a great image. Teradek Live:Air:Action easily won the audio aspect of this showdown.

Apple makes audio in iOS very simple: Either, it comes in via the headphone jack as a mono microphone feed with so-so quality, or comes into the iPad as USB audio, which can be higher quality, and stereo. All of this has nothing to do with the video apps I tested. They can only use what iOS hands them. What the apps do after that, however, is very different.

Teradek features a full audio mixer (Figure 5, below) in the app that can adjust audio from each camera or adjust audio from each video clip you are playing back (very handy for easily making various clips the same level). It also features MP3 playback for music beds. In addition, you can set each channel to be always on, or on only when it's live, which is very handy.

Figure 5. Teradek audio mixer

Plus, there are filters on each channel—high-pass, low pass, and notch—and another section for an audio compressor, on each channel. Like the RGB video, the app is amazingly deep with features, almost to the point where it gets confusing. But Teradek has again done a decent job organizing all the features. It's missing only a Gate filter to cut out room noise from multiple open mics during a production.

Cinamaker places second on the audio side, offering an audio mixer tab with level adjustments for each camera feed (Figure 6, below). Here you’ll also see an audio meter for each input. You can adjust the audio level of video clips you'll be playing back, but there’s no audio meter (at least not one I could find). And there’s no master program audio meter to let you know how loud each audio source is in relation to the others.

Figure 6. Cinamaker audio meter

Another challenge is that Cinamaker is the only app that doesn’t utilize audio coming into the iPad running the Director app. You have to utilize an external iPhone device just to ingest the audio over the network, which I find cumbersome. In my tests, the audio that Cinamaker recorded with the iPhone microphones was consistently very low, even when I had the input audio cranked almost all the way up. Cinamaker needs better overall metering, and better audio ingest to get the nod here.

Switcher Studio accepts audio in the iPad you use to mix the show (Figure 7, below). If you need to mix multiple devices—microphones, laptops, and so on—you need to add an external mixer. It has a program level meter right over the program monitor so you can easily see how loud your program is at any time, but no way to adjust it in the app.

Figure 7. Switcher Studio iPad app

Video clips in the app play back at the level they were recorded at. There’s no way to adjust levels in the app at all. This is a bit surprising considering the depth of the features the app has with video capabilities. In testing I found that dissolving from a video clip to a camera abruptly cuts off the audio from the video clip. Your video might dissolve, but the audio does not. Switcher Studio needs to provide more control and finesse here.

Aside from the apps, monitoring your audio is another issue, again hampered by iOS “taking care of it for you.” Apple places priority based on the last thing you plugged in. So if you are sending a live feed out a HDMI adapter to external monitors, recorder, or a second streaming appliance, audio follows video... unless you then plug in headphones. Then Apple decides to NOT send audio with the video and only send it to the headphones. Why not both? Why not let the user choose? Again, not an app issue, but something you'll have to deal with when you use any of these apps for your live stream.

The Verdict

I think the video clearly shows that if you're producing in 720p, there are slight differences in the quality of the master switched program (streamed or recorded). Whether this is enough of a difference to offset other app features is up to you. I didn't use Teradek's camera sharpening in the low bitrate test so you see each camera at its default settings.

When you push every app as far as it can go, the results change. Teradek Live:Air Action delivers the highest quality 10 Mbits/s 1080p30 live video. It also handles HDMI devices (as I demonstrate in the video) so you can further improve your image over what a cell phone provides.

However, image is not the ONLY thing to consider in producing your live stream. Do you need titles? Do you need green screen? Video playback? Stills? Picture-in-picture presets? Sports scoreboards? Screen capture from a laptop or other device? Instant replay? Etc. Which app best handles _everything_ you have to do as part of the whole program? I did not strive to answer this because the answer is different for each user. It's even different for each program you might need to produce.

No one app is best at everything. But I wanted to see which iOS app offered the best image quality, at this point in time. At any time after this test, any of these apps could update how they compress the image, what codec they use, and what resolutions they handle. One thing is certain — they will continue to improve in the future.

Teradek has a limited Free version, and the Live:Air Action "Bundle" of all the in-app purchases is a one time cost of $149. Switcher Studio offers $29/mo Personal or $49/mo Professional plans, billed annually.

Cinamaker has a limited Free version and a $17/month Studio version, billed annually. Both Switcher Studio and Cinamaker also have month to month plans.