Among the many people that have been addressing the problem of inconsistencies between different types of broadcast programme material over the years is Jeffrey Riedmiller, director of the Sound Platform Group at Dolby Laboratories (pictured). Riedmiller has been behind two of Dolby’s main products in this field, the LM100 broadcast loudness meter and the DP600 programme optimiser, and is a vocal advocate for best practices for loudness.
He is now looking at the next step in dealing with the problem since the publication of standards including ITU BS 1770-2, EBU R128 and ATSC A/85, which are now established and have led to the introduction of regulations or legislation.
“I really feel we’ve come a long way,” says Riedmiller. “Dolby has invested a lot in this – looking at all this information about loudness range, dynamics and metadata – because it’s not only important for correct and proper use of our formats, it’s also important for the creative community, and even all the way downstream to device manufacturers, to understand this stuff and embrace it such that when people are threatened with regulations or fines, they don’t automatically go back to the lowest common denominator.”
Riedmiller feels the task now is for organisations like the EBU and the ATSC to continue working together, with a lot of “smart people” looking at the problem and the practicalities involved, with the ultimate aim of “reducing everybody’s fears and showing them that it’s not that difficult”. The crux of loudness lies in subjective assessments of differing levels, which varies from person to person and has made the whole area appear arcane.
The reality, says Riedmiller, is much simpler: “When you boil it all down and take away a lot that’s been said and written it is about a few key things. We have a great measure that’s been well vetted by a number of people round the world, we’ve got ways to gate the measure on stuff that matters to listeners, ways to measure peaks and transport metadata and establish reference levels on consumer devices.”
Despite this there are still doubts, particularly regarding the best point in the production/delivery chain to start dealing with loudness and whether there are still weak links on the way to the home. Dolby’s position is that loudness should be dealt with correctly as near to the start of the whole process as possible. “If you get a really well produced piece of content, with information representing the loudness and dynamics into the system, then the net result at the other end is exactly what you expect. You get consistency over channels, surfing from one to another and back. Everyone proved that to themselves so the focus is up-stream.”
Like any manufacturer with equipment and technology to sell, Dolby is not restricting itself to one market sector. The company has developed the DP600 to implement loudness controls further down the delivery path, with technology now licensed to other companies. Riedmiller says any loudness technology should form the basis of a simple system for validating and checking material, with confidence that the whole thing cannot be attacked or tricked.
“That can go from the post production studio to the broadcaster to the satellite or cable operator who can check it or say I trust it and then send it on to the home,” he explains. “Where there isn’t the trust or a mechanism of signalling trust, processes can be kicked in to bring things into compliance. If people are working really hard to create compelling content, which plays well across all devices, and all that work is not making it downstream, they might say ‘Why am I bothering, investing so much time in creating this immersive experience?’.”
Another potential danger is that broadcasters, particularly at a local level, and service providers like cable head-end operators will revert to what Riedmiller calls the “safe harbour” approach. If that happens, he warns, it could send TV sound right back to the days of NTSC audio of the 1970s. “Speaking from the US perspective, with local broadcasters taking network content, I think it is possible that could happen,” he says. “We’re at high risk. That also means there’s a risk of stuff being redistributed through cable and satellite too. The premium network feeds are probably at less risk because they’re deeply engaged with the platforms that broadcast the content.”
The threat is probably less severe in Europe, although, there can be dramatic discrepancies between different channels on the same broadcast platforms. The hope is that eventually loudness metering and monitoring will be less confusing or scary to non-audio people because it is just one part of an overall process and not a challenging stand-alone procedure. As Jeffrey Riedmiller concludes, “All the chess pieces are there and it’s starting to make a difference.”