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Track layout and loudness in DPP file format

Kevin Hilton 1 February 2012

New technical and metadata standards for file-based delivery of TV programmes in the UK have been released and include recommendations for audio track layout and loudness control, writes Kevin Hilton. The guidelines were drawn up by the Digital Production Partnership (DPP), formed by the BBC, ITV and Channel 4, and follow a tape-based operations standard published in March 2011. Under the DPP framework seven leading UK broadcasters – Sky, Channel 5, S4C and UKTV, as well as the BBC, ITV and C4 – have agreed on a common file format, structure and wrapper to allow TV programmes to be transferred and delivered in digital file form. The DPP has been involved in the writing of the AWMA (Advanced Media Workflow Association) AS-11 international HD file format and UK broadcasters will have to comply with a specified subset of this new standard. As part of this the DPP has incorporated multi-channel sound, which Kevin Burrows (pictured), technical standards chair of the group and chief technical officer for broadcast and distribution at C4, says is now the norm. Two EBU recommendations have been used as a template for the file-based standard: R48, covering allocation of tracks in basic stereo; and R123 for exchanging audio with multiple channels. Burrows says that under the R123 guidelines files can accommodate up to three different language channels, plus one or more sets of 5.1 or stereo. The DPP is also monitoring progress of the forthcoming SMPTE track labelling scheme. Burrows says the DPP will "probably" adopt this when it has been published, although that might not be for another year, when the UK standards will be due for updating. Loudness recommendations adhere to EBU R128, which Burrows sees as becoming standard. "There’s a fair bit of equipment out there now complying with R128 so it seemed sensible to stick with that," he says. www.digitalproductionpartnership.co.uk 

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