3 set up 870

By Greg Taylor, Support Engineer

Last month I was tasked with scoping the requirements and architecting a solution to live stream an event primarily using components we had around our workshop… “Awesome!”, I thought to myself, “what are the other requirements and what are our options?”

Marketing Manager, Mark Richards went on to provide a few more details – essentially we don’t need anything too fancy, just some simple switching with a basic graphic overlay or two..

Our initial requirements:

  1. 5x iMacs able to mirror their GUI into a vision mixer
  2. 1x cameraman into the vision mixer
  3. 1x MC (audio) into the vision mixer
  4. program out of the vision mixer and into a streaming device
  5. someone to run the mixer and streaming device
  6. no tripping hazards, such as cables running across the floor

Nice to have:

  1. big screen(s) of the Program output
  2. big screen(s) of the Multiview output
  3. audio from the iMacs 4 – bugs, logos, graphic overlays, etc

As we started our adventure, we focussed on the best device to switch our input sources.  There are quite a few SDI switchers out there, but we didn’t want to be converting the iMac Mini Display Port to SDI 5 times – besides, we only have one AJA HA5 (HDMI to SDI powered converter) in the workshop.  We already have a bunch of Mini Display Port to HDMI adapters.. surely there is a switcher with HDMI?

In short time we located a Blackmagic ATEM Switcher – this half rack width, 1RU high unit has 4 HDMI inputs plus a further 4 SDI inputs, all frame synchronised, and there’s a pair of balanced/XLR inputs for the MC... perfect!


Closer inspection shows we have some HDMI and SDI Multiview outputs, SDI program out and Ethernet control – I’m sure we’ll find a use for these later..

The ATEM can be controlled over a network connection using the free tools available on the Blackmagic website – this means we can put the ATEM near the client/input machines and control from a distance.

In our setup, we have gone with 1920x1080 for the frame size, though there were some issues getting the iMacs booting as Windows OS to push a 50i signal – maybe we could spend some time working on a fix here, but instead opted to put the whole system into 1920x1080 60.

On the 5th iMac, we had to convert HDMI to SDI using an AJA HA-5 – very quick and easy, and a perfect signal once we set the correct output resolutions on the client.

For the roaming camera, we were supplied a Sony PXW-X70 – this has an SDI output and we confirmed it can also push the same resolution that we have setup for the iMacs.

OK, video input is looking covered, keeping in mind we need to set all the input sources to the same frame size and rate, otherwise things won’t lock in – we don’t have any fancy frame rate converters and we’re trying to keep the components in the chain minimal – lets look at our audio options..

We should be able to push HDMI with embedded audio out of all the iMacs, providing that the users have the correct audio device selected for their output, but it may get tricky getting Avid Media Composer on Windows OS bootcamped on an iMac to utilise some of its internal hardware chain.

Now to get some audio for the MC – this person is here to talk the audience through the event, add challenges for the editors, and generally keep things upbeat and interesting.

We tried simply plugging a microphone straight into the right XLR input on the ATEM, but couldn’t get enough boost to hear anything clearly, and there was no control to make a mono signal.  To get around this, we added a small Behringer mixer in – this gave us enough boost to get a clean and clear signal through the ATEM.

We also required a 2nd mixer on the other side of the room to take the mixed program output and push it through our front of house speakers.

Now the audio inputs sorted out, we need a box that can stream live to the web – Matrox pointed us toward their Monarch HDX – a quick review of this and we were happy with the available options, as well as the ease of setup – it’s another ½ rack wide, 1RU high unit, the same size as the ATEM.

2 matrox 870

The Monarch HDX is capable of pushing two separate streams from one source – we only need one destination, so this is ample.

Our streaming service is going to be IBM’s uStream, essentially a cloud video service.  We used the links on their website to figure out the best streaming settings for our situation – in this case, 1280x720 was our flavour of choice and should have a low enough bandwidth to ensure a smooth and consistent viewing experience for the end users.

Now we seem to have all our inputs and outputs setup, but there’s no monitoring / eye candy for the punters – ideally we’d like to have a program output on a big screen or two, and it would be nice to see the Multiview output – how do we get this signal around the room without laying cables all over the floor?.. hmmm..

If at all possible, I avoid running high resolution HDMI signals over 10 meters – it gets flakey and can be more prone to dropouts - SDI can be run further, and we already have some SDI cables going through the roof that we can utilise.

The best option for us here was to use an AJA KiPro and AJA KiPro Mini – we are only using them to take an SDI signal, throw across the roof and down close to the relevant monitors.

The KiPro will take the SDI program output from the ATEM and convert it to HDMI for one of the big TV’s on the wall and pass through SDI into the Monarch HDX – the Monarch HDX can then throw its program output over HDMI to the Projector.

The KiPro Mini is then used to take the SDI Multiview output up to the control desk, split SDI to my JVC broadcast monitor and analogue audio to the front of house mixer.

The ATEM’s HDMI Multiview goes direct to our DisplayTen interactive monitor so the audience can see how the program is being switched.

Overall, our connectivity diagram looks complex on the surface.

Eg – our full kit:

Edit Royale

But if we take all this out, we can see a simpler, lower cost setup:

Edit Royale

Looking above, if we take out all the extra client monitoring, live MC and converters used, we are down to a 1 rack wide, 1RU high mix and stream system (ATEM and Monarch HDX), a couple of HDMI and SDI cables (maybe a display port to hdmi adapter for the mac users), computer to control the ATEM, some power and an internet connection.

Edit Royale As we got to the day of the event, we decided to add 2 more MacBook Pros to my desk so I had separate control interfaces – one for video switching, one to monitor and attenuate the audio, and one to take the stream and push over airplay to another big tv in the recreation room so the audience could sit back and watch from there while eating pizza and sipping on their libation of choice.

In hindsight, there were a few things we could have done differently and will keep in mind for next time..

A) Live vision switching really requires a person dedicated for the task to keep up the momentum of the show, as does audio mixing and any technical troubleshooting that may arise – it can be a challenge trying to juggle these three tasks on your own, especially if they all coincide!

B) Audio is very important – to capture more of the audience and general background, a condenser mic in the room would have added to the overall feel for the streaming viewers.. maybe just using the mic on the camera would have done the trick – only thing to consider here is that we had front of house speakers – we need to keep the room mic out of these speakers so there is no echo or feedback loop.

Overall, the event was well received – the competitors, MC and audience all had a great evening, and our solutions architect Pat Trivuncevic was sending me skype updates (remote QC) on the feed while coding away at home.

I guess anyone can stream from a personal device these days, but having the ability to be a portable TV studio that can push a clean, professional looking show to the web is the next level!

Considering the monetisation that can be applied to so many avenues on the web, I can see where this concept may pique a few interests.

If you wish to see the event or the winner’s cuts, please check out the Digistor website.  If you have any questions or would like a demo, please contact the team at Digistor to arrange a meeting – we are here to help you get the most out of your budget and setup!