The Digital Production Partnership's standardised QC Guidelines, released this week, are designed to bring the quality checking process forward in the chain to post-production houses. Loudness is a major part of this but UK facilities are still working to earlier recommendations, so will there be parity in the near future?
In the business world, and life in general, everyone working to the same rules, or overall goals - all reading off the same page in marketing parlance - is preferable to having different targets and regulations for the same thing. Unfortunately the reality is usually that new recommendations, directives and guidelines are often staggered in their introduction, creating a situation where people in the same industry can be working to varying specifications.
This state of affairs exists to an extent in the UK where audio loudness control for television production is concerned. TV commercials are mixed according to guidelines set in 2008 by the Broadcast Committee on Advertising Practice (BCAP) of the ASA (Advertising Standards Authority). Dramas, documentaries and other long-form productions have been mixed to either 6 on a PPM (peak programme meter) or a loudness meter to one of the relevant standards introduced in recent years. In the UK has meant either ITU BS 1770, which appeared in 2006, or EBU R128, launched in 2010, although some broadcasters, notably ITV, still use an updated version of the algorithm written for the Chromatec loudness meter in the early 2000s.
Standardisation is now much closer with the publication last year of the DPP specifications for file-based delivery of programmes to broadcasters. These include R128 for loudness and although it is not yet mandatory, broadcasters, including Sky, have adopted it for their output. The publication this week of the DPP's Quality Control (QC) Guidelines, ahead of the planned shift to full file-based operations by this October, has further consolidated the market in terms of loudness normalisation.
This highlights the existing inconsistency with TV commercials. The BCAP guidelines recommend that advertisements should be mixed on a loudness meter, "ideally conforming to ITU recommendations". But they do allow for facilities still using PPM Type IIa peak meters, stating that commercials should be "at least 6dB less than the maximum level of the programmes". As programmes are usually mixed with a highest target of '6' on a PPM, ads should read 4.5.
Owen Griffiths (pictured), chief engineer with commercials audio post-production specialist Jungle Studios, observes that UK post houses in this sector have continued to use PPMs because video post facilities still have that requirement "because it's what the companies distributing the commercials want".
Griffiths comments that the BCAP recommendations of using either 1770 or PPM4.5 are "probably a little too loose", particularly as 1770 meters can be set to different parameters. Jungle has a variety of loudness units; its main tool is the Nugen system, with other devices, including Chromatec and DK, also offered to satisfy individual broadcasters' requirements. For international projects Jungle is also able to work to the US A/85 and Australian OP-59 specifications, among other national standards.
Despite this making for what Griffiths describes as a "disparate approach", the work done over the last few years in the UK has, he says, led to achieving the same thing everybody in broadcasting and facilities wants with loudness, "ultimately not being fined by Ofcom". He adds, "There are different rules for commercials and programmes but one of the great achievements is that there is a situation where no one is being penalised and there is consistency across all genres."
The main advertisement distribution companies, including IMD and Adstream, also have to work with the recommendations as they are and the occasionally loose implementation of them. John Bolton, director of broadcaster relations and development at IMD, points out that the DDP specs are for programmes but that most post houses now mix ads with respect to R128. "As the UK and Ireland broadcasters have not settled upon one format yet for audio and we deliver to all, like Adstream we ask for all material to peak to -10dBfs (PPM6 BBC Type II PPM) so the post houses simply change the gain of the material to meet PPM 6," he says. "The reality is most audio posts mix sympathetically already so the final mile delivery is largely irrelevant."
Kevin Burrows, DPP technical standards lead and chief technology officer for broadcast and distribution at Channel 4, comments that if all material is mixed to R128 the problem of loudness will be minimised, adding that already there were "fewer complaints" from viewers about this issue. He also says the DPP has been talking to BCAP and suggests that in the end the commercial specifications will be revised. BCAP itself states: "Advertising Code 4.7 (Harm and Offence) of the Broadcast Code still applies in relation to noise levels on TV. We're aware of, and welcome, the DPP's work in this area and we're having discussions with them, which might result in the changes to the Code."