SRS Labs develops headend loudness management solutions
December 5, 2011
Looking to help broadcasters comply with new CALM Act rules that limit audio levels for TV programming and commercials, SRS Labs, based in Santa Anna, CA, has introduced a new line of professional
broadcast solutions for content providers and broadcast operators around the world.
The new SRS HELM (Head-End Loudness Management) HELM family of volume leveling solutions includes HELM-RT (for live feeds or real-time processing applications) and HELM-FB (for offline, file-based workflows). HELM introduces a new integrated solution for loudness management.
HELM-RT was designed specifically for real-time processing of live content. It not only analyzes linear broadcast feeds for compliance, but also automatically and precisely corrects any feeds detected to be out of the set house reference level (-24 LKFS for CALM compliance). HELM-RT uses innovative techniques to minimize alteration of the program stream except when non-compliance is detected. While the intelligence in the HELM correction engine is proprietary, the loudness measurement algorithms are based on international ITU-T: BS.1770-1 and BS.1770-2 standards.
The HELM-FB module is targeted at offline content processing. It includes the ability to analyze an entire short or long form program many times faster than real-time to accurately determine its loudness prior to making corrections. Ideal for VOD content ingest, HELM-FB is used to maintain a consistent volume level and reduce unwanted fluctuations — without altering the program’s dynamic range.
Both HELM solutions, which take advantage of SRS’ participation as a member of ATSC 6-3 (the committee charged with amending the A/85 specification referenced in the CALM Act), have detailed logging features to provide audit trails (history) for proof of compliance.