CALM - A crucial act to follow


Martin Moore TV-Bay Magazine
Read ezine online
by Martin Moore
Issue 101 - May 2015

Sudden jumps in sound level between television programmes and commercials first came to the notice of legislators after a loud commercial interrupted a family dinner at the home of US House of Representatives member Anna Eshoo. The technical parameters adopted in the draft were based on an existing recommended practice document issued in November 2009 by the US Advanced Television Systems Committee.

The bill was signed into law in December 2010 and subsequently took effect as the Commercial Advertisement Loudness Mitigation Act. Anna Eshoo later declared this to be one of the most popular pieces of legislation she had sponsored during her entire 18 years in Congress. Equivalents are now applied by Broadcasters in almost every major country, notably in the form of the International Telecommunications Union Recommendation BS.1770 on loudness measurement: 'Algorithms to measure audio programme loudness and true-peak audio level'.

The safest places to perform audio loudness control are during programme editing and playout. For editing applications, Eyeheight developed a software Plug-In for Apple Final Cut which is widely used by Broadcast Content Producers. This Plug-In provides automatic control of perceptual loudness and true-peak using ITU-R BS.1770 multi-channel loudness and true-peak estimation algorithms, EBU R128 gating (optional) and proprietary correction algorithms to ensure compliance with ATSC A/85, EBU R128 and short-term peak loudness and peak-program level requirements.

Our Plug-In continuously monitors embedded stereo or multi-channel surround audio loudness and seamlessly adjusts system gain across all channels to maximise impact while achieving the target loudness and preserving the spatial imaging. It performs 8x over-sampling true-peak estimation and instantaneous correction to all stereo or multi-channel surround channels to ensure per channel peak-program level limits are adhered to.

Figure 1A shows the short-term perceptual loudness (using ITU-R BS.1770) of two interstitials levelled using a traditional peak-programme level measurement of PPM6. It can be clearly seen that the first interstitial has substantially higher perceptual loudness and far exceeds the defined perceptual loudness limit of 0 Loudness Units (in this case -18 Loudness Units relative to Full Scale, or LUFS). The second interstitial is below the loudness limit and is not taking full advantage of the loudness allowance.

By contrast the loudness history in Figure 1B shows the short-term perceptual loudness (using ITU-R BS.1770) of the same two interstitials once they have been individually processed using in short-term peak loudness mode. The first commercial now conforms to the 0 LU loudness limit and all dynamics have been maintained. The second commercial now makes full use of the available loudness allowance and will have greater presence.

As a result of processing by the Eyeheight KARMAudioAU audio compliance Plug-In, failures are eliminated and maximum use of the available loudness allowance is assured.

Figure 2A shows the short-term perceptual loudness (using ITU-R BS.1770) of two interstitials leveled using a traditional peak-program level measurement of PPM6.

Despite both hitting PPM6, it can clearly be seen that the first interstitial has substantially higher perceptual loudness than the second. The first exceeds the defined average perceptual loudness limit of - 24LUFS while the second is not taking full advantage of the loudness allowance.

By contrast Figure 2B shows the short-term perceptual loudness (using ITU-R BS.1770) of the same two adverts once they have been individually processed using KARMAudioAU in ITU-R BS.1770 (ATSC A/85) loudness mode. Both interstitials now comply with the -24 LUFS average loudness while ensuring that full advantage is taken of the available loudness allowance.

As a result of the processing audio compliance failures are eliminated and maximum use of the available loudness allowance is assured.

Finally the same audio compliance features are incorporated in the real-time LE-2M-K video and audio legaliser which is designed for Broadcast presentation and playout where a hardware processor is often preferred. Embedded stereo or surround audio loudness are continuously monitored, system gain being seamlessly adjusted across all channels to stay within the loudness limit while preserving audio imaging.

Eyeheight Ltd (www.eyeheight.com) was founded in 1992 by Martin Moore and Steve Crocker, BBC-trained engineers who were then working as London-based chief engineers in the post-production industry.


Tags: iss101 | audio | sound level | technical parameter | perceptual loudness | Martin Moore
Contributing Author Martin Moore

Read this article in the tv-bay digital magazine
Article Copyright tv-bay limited. All trademarks recognised.
Reproduction of the content strictly prohibited without written consent.

Related Interviews
  • Glensound show Beatrice the AES67 Network audio intercom beltpack at IBC 2018

    Glensound show Beatrice the AES67 Network audio intercom beltpack at IBC 2018

  • Latest audio product updates from TSL Products at IBC 2018

    Latest audio product updates from TSL Products at IBC 2018

  • Nugen Audio Loudness Meter, Halo Upmix and Halo Downmix at NAB 2018

    Nugen Audio Loudness Meter, Halo Upmix and Halo Downmix at NAB 2018

  • 7.1.2 Dolby Atmos support by Halo from Nugen Audio at NAB 2017

    7.1.2 Dolby Atmos support by Halo from Nugen Audio at NAB 2017

  • Nugen Audio at IBC 2016

    Nugen Audio at IBC 2016

  • AudioVideo BrandBuilder Corp at NAB 2016

    AudioVideo BrandBuilder Corp at NAB 2016

  • Nugen Audio at NAB 2016

    Nugen Audio at NAB 2016

  • Minnetonka Audio at NAB 2016

    Minnetonka Audio at NAB 2016

  • Nugen Audio Loudness Toolkit at BVE 2016

    Nugen Audio Loudness Toolkit at BVE 2016

  • Nugen Audio Halo Upmix at BVE 2016

    Nugen Audio Halo Upmix at BVE 2016

  • NUGEN Audio at IBC 2015

    NUGEN Audio at IBC 2015

  • NOA Audio Solutions at IBC 2015

    NOA Audio Solutions at IBC 2015

  • NUGEN Audio at BVE 2015

    NUGEN Audio at BVE 2015

  • Nugen Audio at NAB 2014

    Nugen Audio at NAB 2014

  • Audio Network on BroadcastShow LIVE at IBC 2013

    Audio Network on BroadcastShow LIVE at IBC 2013

  • NOA Audio Solutions at IBC 2013

    NOA Audio Solutions at IBC 2013

  • NuGen Audio at IBC 2013

    NuGen Audio at IBC 2013

  • NUGEN Audio: Loudness Toolkit at NAB 2013

    NUGEN Audio: Loudness Toolkit at NAB 2013

  • Nugen Audio at IBC 2012

    Nugen Audio at IBC 2012

  • Audio Developments at ProVideo2011

    Audio Developments at ProVideo2011

  • Audio Developments at BVE North 2011

    Audio Developments at BVE North 2011

  • Junger Audio at IBC2011

    Junger Audio at IBC2011

  • Nugen Halo Upmix and AMB Updates at IBC 2017

    Nugen Halo Upmix and AMB Updates at IBC 2017

  • Canford at BVE 2017

    Canford at BVE 2017

  • Telos Alliance at BVE 2017

    Telos Alliance at BVE 2017

  • The Telos Alliance at IBC 2016

    The Telos Alliance at IBC 2016

  • Glensound at IBC 2016

    Glensound at IBC 2016

  • Studer Glacier at IBC 2016

    Studer Glacier at IBC 2016

  • Wohler at IBC 2016

    Wohler at IBC 2016

  • Video Devices PIX-E at IBC 2016

    Video Devices PIX-E at IBC 2016

  • Sound Devices Wingman app at IBC 2016

    Sound Devices Wingman app at IBC 2016

  • Sound Devices 688 at IBC 2015

    Sound Devices 688 at IBC 2015

  • Video Devices PIX-E Series at IBC 2015

    Video Devices PIX-E Series at IBC 2015

  • RTS at BVE 2015

    RTS at BVE 2015

  • Glensound Dante at IBC 2014

    Glensound Dante at IBC 2014

  • NOA Archive Solutions at IBC 2014

    NOA Archive Solutions at IBC 2014

  • RTW at IBC 2014

    RTW at IBC 2014

  • RTW at NAB 2014

    RTW at NAB 2014

  • Sound Devices at NAB 2014

    Sound Devices at NAB 2014

  • Studio Technologies at NAB 2014

    Studio Technologies at NAB 2014

  • Clear-Com ProGrid at NAB 2014

    Clear-Com ProGrid at NAB 2014

  • Clear-Com HelixNet Partyline at NAB 2014

    Clear-Com HelixNet Partyline at NAB 2014

  • Glensound Atomic Copper at NAB 2014

    Glensound Atomic Copper at NAB 2014

  • TSL Products SAM1 MADI at BVE 2014

    TSL Products SAM1 MADI at BVE 2014

  • Glensound Cub at BVE 2014

    Glensound Cub at BVE 2014

  • Calrec on BroadcastShow LIVE at IBC 2013

    Calrec on BroadcastShow LIVE at IBC 2013

  • Wohler Technologies on BroadcastShow LIVE at IBC 2013

    Wohler Technologies on BroadcastShow LIVE at IBC 2013

  • Nexidia QC on BroadcastShow LIVE at IBC 2013

    Nexidia QC on BroadcastShow LIVE at IBC 2013

  • TSL Products PAM1, SAM1 and PAM PiCo at IBC 2013

    TSL Products PAM1, SAM1 and PAM PiCo at IBC 2013

  • Glensound with the USB Commentary Mixer at IBC 2013

    Glensound with the USB Commentary Mixer at IBC 2013

  • TSL Products at IBC 2013

    TSL Products at IBC 2013

  • Calrec at NAB 2013

    Calrec at NAB 2013

  • Sound Devices at NAB 2013

    Sound Devices at NAB 2013

  • TSL Products at NAB 2013

    TSL Products at NAB 2013

  • Thear Technology at BVE 2013

    Thear Technology at BVE 2013

  • TSL Systems at BVE 2013

    TSL Systems at BVE 2013

  • TSL Products at BVE 2013

    TSL Products at BVE 2013

  • AC Entertainment Technologies at BVE 2013

    AC Entertainment Technologies at BVE 2013

  • Pinknoise at BVE North 2012

    Pinknoise at BVE North 2012

  • Shure Distribution at BVE North 2012 LIVE Show

    Shure Distribution at BVE North 2012 LIVE Show

  • RTW at NAB 2012

    RTW at NAB 2012

  • Sonifex at NAB 2012

    Sonifex at NAB 2012

  • Sound Devices at NAB 2012

    Sound Devices at NAB 2012

  • Emotion Systems at NAB 2012

    Emotion Systems at NAB 2012

  • Clear-Com Eclipse MADI Card at NAB 2012

    Clear-Com Eclipse MADI Card at NAB 2012

  • Glensound at NAB 2012

    Glensound at NAB 2012

  • TSL at NAB 2012

    TSL at NAB 2012

  • Triveni Digital at NAB 2012

    Triveni Digital at NAB 2012

  • Petrol at NAB 2012

    Petrol at NAB 2012

  • Qualis at NAB 2012

    Qualis at NAB 2012

  • Calrec at NAB 2012

    Calrec at NAB 2012

  • DK-Technologies at NAB 2012

    DK-Technologies at NAB 2012

  • Glensound at BVE 2012

    Glensound at BVE 2012

  • Calrec at BVE 2012

    Calrec at BVE 2012

  • Sonifex at BVE 2012

    Sonifex at BVE 2012

  • DiGiCo at BVE 2012

    DiGiCo at BVE 2012

  • 4HM at BVE 2012

    4HM at BVE 2012

  • Thear Technology Limited at ProVideo2011

    Thear Technology Limited at ProVideo2011

  • 4HM at BVE North 2011

    4HM at BVE North 2011

  • TNP and DSMB at BVE North 2011

    TNP and DSMB at BVE North 2011

  • The Mic Store at BVE North 2011

    The Mic Store at BVE North 2011

  • Sennheiser at BVE North 2011

    Sennheiser at BVE North 2011

  • Source Distribution and Genelec at BVE North 2011

    Source Distribution and Genelec at BVE North 2011

  • HHB and Soundfield at BVE North 2011

    HHB and Soundfield at BVE North 2011

  • Riedel at BVE North 2011

    Riedel at BVE North 2011

  • Solid State Logic at IBC2011

    Solid State Logic at IBC2011

  • Dolby at IBC2011

    Dolby at IBC2011

  • Murraypro at IBC2011

    Murraypro at IBC2011

  • Calrec at IBC2011

    Calrec at IBC2011

  • TC Electronic at IBC2011

    TC Electronic at IBC2011

  • SADiE at IBC2011

    SADiE at IBC2011

  • RTW at IBC2011

    RTW at IBC2011

  • Prodys at IBC2011

    Prodys at IBC2011

  • DK Technology at IBC2011

    DK Technology at IBC2011

  • Linear Acoustic at IBC2011

    Linear Acoustic at IBC2011

  • Sound Devices at IBC2011

    Sound Devices at IBC2011


Related Shows
  • The future of audio with BBC R&D at BVE

    The future of audio with BBC R&D at BVE


Articles
Ruth Matos Interview - A Career Unfolds
Ruth Matos We first met Ruth when we employed her as a student to help with our live studio at BVE in 2013. We were struck by her determination, passion and ‘I’ll do anything to help’ attitude. We became friends of Facebook and have since seen her career in the industry develop and unfold. We thought it was about time to catch up and share her inspiring story of where she is now, how she got there and the challenges she has faced along the way.
Tags: iss133 | interview | filmming | career | education | Ruth Matos
Contributing Author Ruth Matos Click to read or download PDF
Perimeter LED screens management
Nicolas Houel Opened in January 2016, Parc Olympique Lyonnais, also known as Groupama Stadium, is the new home of Olympique Lyonnais football club, one of the most popular clubs in France. Since its inauguration, the stadium was a host of UEFA Euro 2016, and was also chosen to stage, among other important events, the 2018 UEFA Europa League Final and football at the 2024 Summer Olympics.
Tags: iss133 | 3dstorm | graphics | groupama stadium | liveexpert | livecg | deltacast | Nicolas Houel
Contributing Author Nicolas Houel Click to read or download PDF
Peli Air 1507 Review
Phil Vinter Originally named after a bird that carries its precious cargo through the skies, it was, perhaps, only a matter of time before Peli released its Air range.
Tags: iss133 | peli | peli air 1507 | trekpak | Phil Vinter
Contributing Author Phil Vinter Click to read or download PDF
The Biggest Toy Shop in the World
Emma Morrison When Nigel Woodford started his career at BBC Wood Norton in 1962, television was black and white and BBC Two had not yet been launched. In 2018 Nigel will retire, and Richmond Film Services, the pro-audio equipment rental company set up by Nigel in 1973, can count numerous contributions to iconic moments in British cultural, sporting and film history over this time.
Tags: iss133 | richmond film services | audio rental | auction | liquidity | go-dove | Emma Morrison
Contributing Author Emma Morrison Click to read or download PDF
How todays technology platforms can make AMAZING seem mundane
Bruce Devlin - new Some things never change. It's September and it's time for another IBC. Maybe I'm getting old and maybe I have selective memory about the past, but recently there hasn't been the buzz of years gone by. Sure, as you wander around the vast halls there will be lots of enthusiastic sales people trying to give you the best demo possible, but something has changed and to survive, I believe that vendors and customers need to change too.
Tags: iss133 | ibc | class | vulture | imf user group | Bruce Devlin - new
Contributing Author Bruce Devlin - new Click to read or download PDF