So you want to switch and iso record 10 cameras, huh?

So you want to switch and iso record 10 cameras, huh?

Last week, a client approached me about setting up a 10-camera live switching operation. That's a lot of cameras! Oh, and all the cameras are remote. And he wants to iso record each camera. All doable. But, the budget is not large. This led me on research binge to determine if it could be done for under $20K.

vMix Go with 8 SDI inputs

I started thinking about vMix. The vMix GO solution is pretty sweet, but like anything, has its limitations.It can be configured with eight Serial Digital Interface (SDI) video inputs, but can receive additional video streams via Real Time Streaming Protocol (RTSP) over Internet Protocol (IP) via an ethernet network. This requires a compatible camera, such as this one from PTZoptics.

PTZoptics 12x robocam

RTSP is an H.264 or H.265 compressed video stream. You are going to have a bit of latency, compared to SDI, depending on network conditions and other hardware. However, you have the benefit of also being able to control the PTZ camera via the network at the same time! One cable for video/audio and control. Pretty sweet. But that latency! In a live event environment, you don't want two cameras that are behind all the rest. One cool thing about vMix is that you can configure your own custom PC to run it on. That means you could put in two PCIe capture cards to get up to the required ten inputs. However, knowing what we are on the verge of with NDI makes it seem almost wrong to be thinking about capture cards.

Newtek NDI video over IP

NDI is Newtek's Network Device Interface technology. It's similar to RTSP in that it allows transmission of audio and video over Internet Protocol (IP). However, NDI goes further, faster! NDI is bi-directional, so it's not just a one-way street. The video and audio is encoded at one end and decoded at the other, for a visually lossless, very low latency transmission that looks indistinguishable from SDI video. Unlike SDI, NDI can transmit an alpha channel (transparency) and other data like tally and talkback. All this over a standard gigabit network! Now do you see why a capture card seems quaint?

There are scads of articles littering the internet, saying that so-and-so's cameras are now NDI compatible. Those are a bit frustrating when what we really need/want is a camera, with an ethernet jack, that can be plugged directly into the network and be 'seen' and recognized as an NDI source, by whatever system is in use on that same network; i.e. TriCaster, vMix, etc. For now, one must run Newtek NDI Connect Pro software on a separate PC, on the network. Connect Pro will "see" the RTSP streams––or SDI inputs if using a capture card–– and basically convert them into NDI sources that will available to any NDI capable software on the network. There are four down sides here. 1] Connect Pro costs a grand. 2] You need a second PC. 3] Your video signal is already RTSP compressed before it becomes an NDI source. 4] NDI Connect Pro can only convert four video sources, per license, per PC.

Unfortunately, there are no native NDI cameras on the market yet. I would guess that in a few month's time, the aforementioned PTZoptics camera will have NDI, built-in. Or will it be JVC, or Panasonic, or Sony that gets there first?

You could instead run a second copy of vMix on a secondary PC to make those sources NDI available, on the network, to the master vMix PC. Or you could have an SDI capture card on the secondary PC to eliminate the RTSP compression.

It's hard to say just how many total sources; SDI, RTSP, NDI one could bring in to the vMix GO before something bottlenecks. According to Martin, the creator of vMix;

"As for inputs themselves, 10 inputs is fine as long as only 4 need to be recorded. It may be able to do more as it is not a fixed limit, but any more than 4 ISO recordings is probably going to exceed the CPU limit." ISO refers to input sources that are being recorded in isolation. I know you want to record 10 video sources, but it looks like the CPU is the first limiting factor, not the SSD storage speed.

As you can see, things are not entirely straightforward when you want to switch and ISO record 10 cameras, on a budget.

Another possible route/solution, is NewTek's TriCaster. A TriCaster Mini SDI model can take in four SDI sources, and, if it's running Advanced Edition software, it can take in four NDI sources in addition, for a total of eight sources.

Newtek TriCaster Mini SDI

However, we run into the same limitation as the vMix Go––only four streams can be recorded simultaneously. If we add a second PC running Isocorder Pro, we can use that to record up to 16 NDI sources! However, the sources would have to go into the TriCaster first, or into a second PC with NDI Connect Pro, in order for them to become NDI available. So, in this case, it makes sense to use a system with 10 capture card inputs; i.e. a custom vMix PC.

The bottom line is that in order to do what we want––switch and record 10 cameras––we will need a switching PC and a separate recording PC.

A beefy custom vMix PC with 10 SDI inputs –– $8K

vMix control surface –– $2,200

A recording PC running Isocorder Pro: $6K

5 PTZoptics cameras –– $8K

4 POV lipstick cams –– $800

1 wifi camera –– $800

Cabling & Network –– $1,200

Install/Configuration –– $2K

Total Ballpark Cost: $29K (before tax)

Jason Jenkins

Video Producer/Sales Engineer

22nd Jun 2016 Jason Jenkins

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