This thing called NDI

A long time ago I predicted mobile phones would be a flop. Who'd want to be continuously available for phone calls? Boy was I wrong. And frankly I still don't get it, I enjoy my occasional time offline.


Fortunately I did get it right a few years ago when I knew NDI would mean the breakthrough of live video production. The sheer amount of conversions required to get a camera feed into my vision mixer, not to mention the costs to pay for all these converters, just never made any sense to me. The NDI story really started 2 years earlier when Andrew Cross, President & CTO of Newtek, sent me an email and asked me how I was doing. Huh? The president of the company I've been admiring so much, the company I considered my biggest competitor, contacts me out of the blue and asks me how I'm doing? It did not take long to realise he was not planning to make me a wealthy retiree, quite the opposite in fact: I think he was looking for allies for this new idea he had.


Sure enough some time later NDI was announced officially and I was invited to test it. He must have been reading my mind all along. I was excited and jumped right in. Most of my work was set aside while I invested thousands of hours in testing NDI, fighting over details, getting angry over bugs (sorry Andrew), and achieving the best performance using the least amount of resources. It also became clear quite soon that where Newtek expects conditions to be perfect, my clients operated under slightly less ideal circumstances. So while Andrew was perfecting NDI, I started developing a shell around NDI that measures jitter, latencies, adds optional buffering with clock recovery and makes sure all feeds remain perfectly synchronised. That way it would work just as perfect for productions with a smaller budget. And it soon paid off: after comparing all vision mixers that support NDI, both software and hardware, a Swedish company was the first to choose VidBlasterX for being the most efficient and stable vision mixer they could find. Many successful productions followed since.

So what is NDI, and what makes it so special? It's really quite simple: NDI is just a protocol to send video and audio over your network. Sort of like what your security IP camera does. There's really nothing special about it. It's the implementation of it that makes the difference. If you've ever tried to hook up an IP camera you know there are protocols that need to be considered, IP addresses (that keep changing when you don't want them to), poor performance causing hiccups in the video, etc. It can be a nightmare. Now imagine having 20 IP cameras that all need to work perfectly, from the start, and of course fully synchronised. NDI makes all the headaches in this go away. It's true plug & play: every NDI source added to your network will instantly show up in every NDI receiver. It's like virtual SDI cables with a name tag. Forget IP addresses, NDI takes care of that. Forget bit rates and compression settings, NDI will find just the right balance of compression and quality to make you forget there isn't an actual SDI cable involved. Need more cameras? Add more. After adding a few you may need to upgrade to a 10 Gb network, but that's about as difficult as it gets. And recently these networks hardly cost more than a proper 1 Gb network. Some PCs even come standard with a 10 GbE port now. Chances are you already have the network equipment, so all you really are looking at is investing in an encoder that converts the camera signal, be it HDMI or SDI, into NDI (i.e. an ethernet port). These are currently available from both Newtek (Spark Connect) and BirdDog. There are even PTZ cameras that have built-in NDI support. Of course, by now you probably have a PC with a capture card lying around doing nothing, so why not install a (9 US$) version of VidBlasterX and turn it into the perfect NDI encoder? It even comes with diagnostics the hardware equivalents don't offer.

But it doesn't end there. NDI can also be used to send a vision mixer's output to remote multiviews, studio floor monitors and IMAG, or in fact to other vision mixers. Not ready to give up your tricaster but need some more inputs? Have another vision mixer take the additional inputs and send a premix to tricaster. The possibilities are endless.


If this all overwhelms you, or you simply feel uncomfortable moving your production over to IP, know that with every VidBlasterX Broadcast licence you get my personal support for free. And if your next production happens to be in Sweden, I know a few guys I can highly recommend as well :).


All photos by Johan Lundberg taken during a recent orienteering production where NDI was used extensively. VidBlasterX processed 20 NDI sources and needed just one CPU..

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