The evolution of vision mixers

Trickbox TV - vision mixing

This article first appeared in the August edition of the KITPLUS magazine.

At the heart of any multi-camera production is a vision mixer – or ‘production switcher’ as some people call them. Its core role is the switching of different sources, primarily cameras, often VTs and sometimes incoming external sources such as remote feeds from broadcasters. Even for non-TV types, that’s relatively simple enough to get your head round – several different incoming video signals can be switched from one to the next. Vision mixers come into their own when you look at their secondary features of keying graphics, transitions and digital effects.

The above features aren’t anything new and have been around since the first vision mixers came out. There’s naturally been progression and improvements to vision mixers and we’ve seen the obvious transitions from analogue to digital, SD to HD, and now 4K (and even 8K!).

But the last few years have seen some greater developments in the world of vision mixers. The two key defining aspects of the changing face of vision mixers are the new concepts of multi-use and multi-functionality, and the connectivity standards i.e. moving from baseband video to fibre and IP.

One big change and what has helped the progression of the concept of vision mixers being ’multi-use’ began when they started including built-in multi-viewers. This proved a huge benefit to the compact vision mixers, transforming the operation of small studios and outside broadcasts.

The introduction of internal video clip stores and integration with video servers has also been a big step forward in efficiently streamlining workflows. For smaller studios – like shopping channels and in-house corporate studios – keeping head counts down is a key factor in their operating model. So ‘all-in-one’ vision mixers and multi-function vision mixers are the way forward. Ross’s range of vision mixers, combined with their Dashboard software are quite elegant, with integration with their other product ranges including their video routers, servers, graphics systems and robotic camera systems. With increasing inputs and outputs being squeezed into smaller frames, vision mixers are essentially video matrices these days. For smaller installations, a separate video router may not be needed.

The introduction of 4K production has highlighted the issues surrounding data and bandwidth. 4K and indeed 8K are forcing our hand to develop IP broadcast faster as moving 4K video around isn’t as easy as HD video. In the world of vision mixers, quad link isn’t that practical. Some vision mixer manufacturers have introduced updates and modifications to their existing HD vision mixers to allow them to handle 4K, but it feels like a workaround. Manufacturers like Blackmagic Design have firmly adopted the single link standards of 6G and 12G, meaning their 4K ATEM vision mixers are both powerful and user friendly. The other options over SDI are either fibre or IP. Wide-spread adoption of fibre IO in vision mixers hasn’t taken off, but there are some manufacturers like SAM (formerly Snell) that are doing it well. But is IP the future – to help combat the 4K data conundrum – for vision mixers?

The issue is that however central and integral the vision mixer is to any multi-camera production, it is essentially only one part of bigger chain – so development of any broadcast system equipment, be it vision mixers, or cameras, video routers and video servers, are tethered to each other. One device can’t change their standards and connectivity without the other – the whole production workflow has to be integrated. Sony has been quick to recognise this and are busy behind the scenes working on what they call their ‘IP Live Production’ solution. All the other big manufacturers like SAM, Grass Valley and Evertz are also developing new ranges of IP broadcast equipment. But it’s a slow burn…

While it’s new and a break from traditional workflows, IP as a broadcast standard is essentially a simple concept – all devices in a multi-camera facility are connected via an IP router. Any legacy devices that use SDI are converted to IP. This offers greater flexibility and greater possibilities. From a studio installation point of view, this simplifies this greatly, plus it allows for a greater level of redundancy. Using IP switches, you can employ an automated failover system (without interruption), for very little cost. If a traditional video router failed – once you’d picked yourself up off the floor – you’d need to manually patch every signal as required to ‘patch around’ the router. Cost is an important factor here as traditional video routers are sized and defined by the number of physical ports, and that bears a direct relationship to their cost. With IP switches, the size of the router is defined by its total bandwidth and not the physical ports, as each port of an IP switch can carry multiple signal paths and are inherently bi-directional.

The drive behind moving to an IP broadcast model has been helped varying factors including the SMPTE 2022 standardisation of video over IP. Plus the adoption of 10-Gigabit Ethernet rather than 1-Gigabit Ethernet in some devices – and now increasingly 40-Gigabit Ethernet devices – demonstrates the industry is embracing a bandwidth hungry, IP ready audience.

Perhaps the most forward-looking and game-changing feature that IP broadcast can bring to the party is remote production. From a vision mixing point of view, the vision mixer and operator don’t even need to be at the same venue as the event or production. It can all be connected via Ethernet, and across the Internet. It’s an exciting premise.

But it’s what users want to achieve with vision mixers today that’s the biggest change. New breeds of users and different types of organisations, such as corporates, educational and minority sports institutions, are all now broadcasters. They’re all trying to reach and engage with new audiences. To do that they need more functionality and intuitive operation – and all at a reduced cost.

So what are vision mixers going to look like in the future? They’ll probably always look fairly similar – lots of buttons, a ‘T-bar’ – but they’re certain to be more powerful then ever before.

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