In Broadcast - May/June 2011 - 41

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Live Production from Grass Valley Cont.
network to the Final Cut Server. As well as the content, all the metadata is transferred as an XML file. An individual editor, for example, might be asked to produce the story of how a rider moved from a position near the back of the starting grid to win the race. By searching the name of the rider and the “passing” clips, the material required will drop into the edit bin, and because the metadata also includes the time, the clips will even be in the right order. This is a massive boost in productivity. Remember that this is not a fixed installation: it has to be moved to each event, which are in different countries. Live production requires not just complex technology but highly reliable equipment which can be packed up and re-implemented quickly and reliably. the next source on the preview bank, then cuts, mixes or wipes to it. The principle is sound, but when you might have 40 cameras, a similar number of replays, plus video stings and graphics overlays, managing it becomes rather more challenging. So Grass Valley engineers continued to develop new solutions to help the operator focus on capturing the excitement of the event without getting bogged down in too much complexity. In the early days, graphics were keyed onto live pictures in an external device. Digital video effects, too, started out in standalone boxes. Digital stills and short clips required their own servers. Today the expectation is that all of this will be included within the production switcher.

LDK8000 SportElite

K2 Dyno

Production Switchers
The final part of the challenge is to bring all these live and recorded sources together into a slick and seamless production. That requires a switcher, and if there is one product with which the name Grass Valley has been associated it is the production switcher (also known as a vision mixer in Europe). It all dates back to 1969 when the model 1400 was launched. This was a ground-breaking device, and it set out the basic format which all production switchers use to this day: two rows of buttons for preview and on-air, with a T-bar for controlling the transition between the two. The operator selects

The key to making this practical was the concept of the mix and effects processor, or M/E. Essentially this is a sub-level production switcher which has keyers and DVE, as well as the ability to cut or mix between sources. By including a number of M/E banks in a single switcher, one operator move from one complex, multi-layer set-up to another. Bringing the clip and still store into the production switcher meant that a single action could trigger multiple events, so moving from one image to another, or from one M/E bank to another, could be covered with a short video clip as well as a complex DVE transition. The production values which could be attained were limited only by the director’s imagination. The downside, though, is that by now the production switcher has grown extremely complex in appearance.

Each M/E bank – and the largest Grass Valley Kayenne™ switcher has four – has its own twin rows of buttons and T-bar, plus access controls for effects, wipes, stills and clips, and all the other functionality required. It is a big device with a lot of controls. User-defined colours for each button helps enormously with navigation, but in a busy show it is not practical for an operator to set up and play every single transition. The logical step was to build in automation, with effects sequences programmed in advance and recalled when required. Grass Valley developed this functionality and called it effects memory or E-MEM. Today’s Kayenne switcher offers 1,000 E-MEM registers for storing as many different effects: more than you would probably need, but it does allow the operator to organise them logically for the production in hand. E-MEMs have a timeline: they describe how a complete effect is going to appear on screen. To take a very simple example, you might want to add a graphic to the programme output, mixing it in over 10 frames.

You could, of course, do this – over approximately 10 frames – by setting up the graphic in one of the keyers then using a T-bar to bring it in. But doing it with the press of one button is much more secure. More complex effects can have multiple keyframes. E-MEMs can be prepared in advance and stored on a USB stick, so they can be loaded into the switcher whenever required. The same goes for graphics and video clips. Sky Sports in the UK, for example, has a distinctive look which depends on key and fill graphics which are prepared in the broadcaster’s headquarters then loaded onto the production switcher or its associated clip server in the truck for each job. By standardising on the Grass Valley switcher and server platform, just one set of files need be generated, which again can be carried to site on a memory stick or downloaded via an FTP site. The output of the switcher is what we at home enjoy. Absolutely critical to that enjoyment is the skill of all the staff involved: operators of switchers, cameras and replays. The role of the technology is to allow them to exercise their skill and experience, letting them focus on the action by automating the routine and guaranteeing the quality.

Kayenne Video Production Center

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