Essential Install Future Tech Trends 2017 | Page 23

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The BBC says many more compatible sets will launch in 2017 worthwhile upgrade for everyone . We believed in wider colour gamut , we believed in high dynamic range and we still have strong views about frame rate .”
Of course , all those things are offered by other HDR formats , but as Phil explains , none quite met the BBC ’ s requirements .
“ We started thinking about how some of those solutions would fit into a broadcast structure as complex as the BBC ’ s . And we started to see quite big operational problems for us . We started to think about how we could do it ; how could we make HDR work in a broadcast environment ?
“ We started talking to the ITU ( the United Nations specialised agency for information and communication technologies ) and found we had similar ideas to NHK . Effectively the ITU were saying – if we ’ re going to have two solutions , which in itself is quite a major change to the ITU – we can only have one particular solution in the area where the BBC and NHK are working . So , we worked quite closely with NHK to converge our solutions into a common approach ; which is part of BT . 2100 , the same way Dolby ’ s solution is .”
The solution that the BBC and the NHK came up with was HLG and it has a few key differences to the other HDR formats on the market . That ’ s because the current HDR formats require metadata ; something the BBC would rather not deal with .
“ We absolutely wanted a system that is metadata free , and that really was driven by our experience of trying to maintain end-to-end metadata such as 5.1 audio . It ’ s just incredibly difficult in a live broadcast environment to make end-to-end metadata work reliably ,” says Phil .
“ When it goes wrong it can have such a massive impact on the content . 5.1 audio is still troublesome for us , the equipment doesn ’ t always work properly , metadata goes missing , sometimes the wrong metadata comes through the chain – which is even worse than metadata going missing . So , for us , no metadata was one of the big issues .”
Reliability was also a big issue for the BBC . The broadcaster has to deal with several different types of content at once ; whether that ’ s a whole series of trailers , a squeeze of the credits or putting a trailer up for the next programme . Those types of operations would be made infinitely more difficult if metadata is required .
“ They ’ re do-able , but you need a lot more complex operations in the play-out world . We just couldn ’ t see how we could make that work reliably ,” Phil notes .
It wasn ’ t just about reliability issues . “ We wanted something that was backwards compatible . It ’ s a pretty simple request , although it ’ s one that is a major requirement for broadcasters around the world .
“ Broadcast spectrum is very precious , and even in IP – distributing multiple assets has a knock-on effect , so you ’ ll see the end-costs rise . So we wanted something that was backwards compatible between HDR and SDR .”
Of course , that doesn ’ t mean those with an SDR TV will be able to suddenly watch HDR content . In fact , the solution is more advantageous to the BBC than it is to the end-user , as it allows the broadcaster to send just one signal for SDR and HDR footage , rather than splitting them up into different streams .
The backwards compatibility will have some advantages for those with an SDR TV , however . That ’ s
10th-11th May 2017 , Sandown Park , Surrey . Sponsored by March 2017 | 21