Shift to file-based delivery continues with new DPP and EBU specifications5 December 2014
Broadcasters and post-production houses have been moving over to file-based operations in recent years. As part of this there has been a shift towards automated quality control (AQC), including checks for loudness and audio channel configuration. This development has accelerated in recent months and is set to continue into 2015.
At the end of November the EBU (European Broadcasting Union) was due to publish a supplement to its R128 loudness standard, providing guidance on monitoring and control for short-form material such as commercials and promos. In the UK the Digital Production Partnership (DPP) will amend its specification to include momentary and short-term measurement when the EBU has published the update and broadcaster tests have been completed.
Loudness, in the form of R128, has been part of the DPP’s proposals and subsequent specs since the body – formed by the BBC, ITV and Channel 4 (C4) – published its tape-based standards in 2011. Since then it has released specifications for file operations, setting the target of 1 October this year for all British broadcasters to have either fully adopted this way of receiving and delivering programmes or begin the transition.
The DPP reports that every UK broadcaster is now using R128, after setting the target for full adoption at the end of September. BT Sport has been fully file-based since it went on air in 2013 and now expects all material delivered to conform to the DPP AS-11 specification, as does Channel 5. ITV and C4 made “a full transition” on 1 October, with file-based as the default standard for received programmes. The BBC is phasing in this methodology, starting with network productions from both its in-house departments and independent producers. BSkyB is also taking DPP AS-11 format files and plans to finish migrating to the format by the end of October 2015.
As part of this a number of manufacturers have had products tested and passed under the DPP’s Compliance Programme. Among these, which have also gained AMWA (Advanced Media Workflow Association) certification, are Telestream, Root 6 Technology, Cinegy and Dalet/AmberFin. “The programme has had a very positive response from the industry,” comments Kevin Burrows, DPP technical standards lead and chief technology officer for broadcast and distribution at C4 (pictured). “This is a great endorsement of the value of the DPP’s standards and guidelines, and thanks to manufacturers’ enthusiastic engagement we are expecting many more products to be certified.”
International loudness specifications for long-form programmes began to be established from 2006 onwards, but in Europe national bodies such as the DPP have been waiting for the EBU to finalise R128 for shorter material, including commercials, interstitials and promos. Two leading advertising and programming distribution companies in the UK, IMD and AdStream, recently wrote to Kevin Burrows on behalf of the wider market regarding changes to the DPP’s Commercial Standards.
In terms of audio, Burrows’ reply covered audio silence as well as loudness. He wrote: “There has been some confusion about the number of frames at the start or end of commercials that should be mute. This should be six frames (historically it was 12), with full audio soundtrack during the rest of the material.” On loudness he added that there would be “further amendments” to the DPP spec covering momentary and short-term measurement following the formal publication of the EBU’s supplement to R128.
An EBU spokesman told PSNEurope in mid-November that this specification was in the final approval stage and that if there were no objections it would be published at the end of the month. “For short-form content such as commercials and promos – as well as interstitials – there is a special need to give guidance using the parameters Maximum Momentary Loudness or Maximum Short-term Loudness in addition to the basic parameters Programme Loudness and Maximum True Peak Level,” he said.
The spokesman confirmed the R128 supplement will provide this guidance and also clarifies that the LRA (loudness range) measure should not be used for short-form content. “LRA is based on a statistical analysis of Short-term Loudness values (3s),” he explained. “For commercials and promos this leaves too few data points for a meaningful result.”
By adopting AMWA and EBU standards the DPP is hoping that it will be able to specify its delivery requirements to international broadcasters. Kevin Burrows stated during IBC that the group was “in dialogue” with major studios in the US with the aim of getting them to work to its guidelines as time went on. “This would reduce the number of versions from 20 to 10,” he says. “It would be a great advantage.”