Loudness has always been a part of Florian Camerer’s work as a broadcast sound engineer but in the last two years it has dominated his life. As chairman of the EBU PLOUD group he presided over the announcement of new guidelines to solve the problem during IBC 2010. But, he tells Kevin Hilton, this is just the beginning.
Florian Camerer (pictured at IBC) and a cross-section of broadcast technicians, manufacturers and researchers from round the world have been grappling with the thorny issue of loudness since 2008. PLOUD had the task of building on the ITU BS 1770 algorithm and recommendations to create a practical guide that gets away from peak levels to deal with the critical area of perceived loudness. The result is R128 and four accompanying documents, launched with triumphant words by Dr Hans Hoffmann of EBU Technical at a press conference during IBC: “Today we can claim victory over loudness!” Florian Camerer is no less enthusiastic about what R128 can mean for broadcasting but is more circumspect in how much it can do right now. “That’s typically Hans,” he laughs when asked about his colleague’s bold announcement. “We now have the tools to achieve victory. We haven’t won yet but the chance are good – they’ve never been better. The will of broadcasters is there, they want to level transmissions out – they don’t cause this situation deliberately.” There is the feeling that why there may not be deliberate intent, commercial pressures – both through advertising and automating operations – have brought about the loudness situation ruins an evening’s TV watching for a significant proportion of viewers. Camerer saw ITU 1770 as a good start but knew there was more to be done: “The ITU specified the algorithm but not anything like the target level and where the common loudness level should be. It’s a measurement tool, which is important because it sparked off the whole development but it needed more.” Earlier this year the ITU issued BS 1864, covering loudness target levels in international programme exchange. Camerer says the EBU wanted a broader picture, going beyond programme exchange into production, distribution, transmission, set top box manufacture and, perhaps most important, what the consumer expects and needs. “That was our goal, to really have a whole body of documents, strategies and guidelines to cover the whole system of loudness normalisation over the whole chain,” he says. “The ITU didn’t specify that or say what should be used but with R128 we have that now.” R128 offers what Camerer calls “additional goodies”, including a gating method. Like 1770, R128 is a foundation. It specifies loudness normalisation and permitted maximum level of audio signals and was always intended to be, in Camerer’s words, “short, precise simple”. The detail comes from four accompanying documents. EBU Tech Docs 3341 and 3342 were published at IBC with R128. Loudness Metering is defined in 3341, with specific details for loudness meters, known as EBU Mode, while 3342 covers Loudness Range, describing loudness normalisation as set out in R128. Two longer, weightier volumes were not finished in time for the Amsterdam show and are still awaiting approval by the EBU Technical Committee before publication. Both are Practical Guidelines: Tech Doc 3343 for Production and Implementation, with 3344 covering Distribution of Programmes. The aim with R128 is to achieve consistency but critics of the process do not see a consistent international approach. The ATSC (Advanced Television Systems Committee) in US has taken a firm stance with A85, while Australia has its own methods and guidelines, all in addition to the ITU specs. Camerer acknowledges the differences, with A85 leaning more towards dialogue, but sees these individual international standards as “pulling on the same side of the rope”. There are subtle differences, he says, and whether these can be harmonised has to be seen but there is the opportunity for them to feed into each other. “Maybe the ITU will adopt a gating method,” he comments, “We have done a lot of input documents for the next ITU meeting based on the results of R128. But I would call it flavours and not a conflict, because the basic idea is the same.” PLOUD was inaugurated at IBC 2008. There was optimism that the first results of its work would be seen at the show the following year but the process took longer than expected. Even with the publication of R128 there are still inherent problems, not just with international exchange or commercials coming from post-production houses, but often within broadcast centres. Camerer reacts with a weary smile at the mention of mono compatibility, with M3 and M6 often used in different parts of a broadcast chain. He acknowledges this is still a serious point but says that regardless of the format used, it will still have a loudness level. “Whether something is mono or derived from an ITU down mix it will have a loudness value and that will be used, in the case of R128, as a useful, good baseline measure for all programmes,” Camerer explains. “Of course, there can always be improvements on this segment or that, for dialogue or music, and loudness normalisation should not be based on a single value. But that is the expert mode. Once we have a baseline figure for everything, which is good for the consumer because he switches between many kinds of programmes, we might move into the next step with different settings for different genres of programming.” The cynical view is that commercial broadcasters can be led by the advertisers, not technical good practice. Camerer believes that both groups want to comply with guidelines to produce the best possible TV that will not annoy the viewers – at least not in technical terms. This, he says, will involve some reverse psychology: “We can sell loudness guidelines to advertising agencies by saying that their competitors won’t be allowed to be louder than they are, so they themselves will stay within the recommendations.” Camerer hopes that as the first broadcasters begin to adopt R128 more will follow to create a voluntary compliance. He acknowledges that he has become closely identified with the subject of loudness and PLOUD in particular but gives credit to not just his colleagues on the group but also those in other organisations for working together to solve the problem. Even if Camerer stepped away from PLOUD now it would still have an influence on his day job as a senior sound engineer at ORF. “It’s back to what we should be doing,” he says, “mixing by relying on our ears, not meters. That’s bad news for lazy engineers because this way of working needs you to listen. You can’t lean back, push the fader and let the limiter do the rest. Now you have to use your ears, which is quite liberating.” While happy with the result of PLOUD’s deliberations since 2008, Camerer sees now as a transitional point. “What we’ve done will stand the test of time but that doesn’t mean it can’t be improved,” he comments. “So PLOUD will live on because this is only a first step – an important one but it’s not the end of the game.” And it’s a game Florian Camerer will carry on playing. “Once I decided to do this I knew it had to be done until the very end,” he laughs again. “I knew it would be a lot of work because this is the most fundamental change in audio for a long time. But I think it’s worth it. When we get this right it will be something really profound.” www.tech.ebu.ch