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tied frame-accurately to video, for any number of channels. This affords the operator the ability to “dial back” and evaluate the content in question, whether it aired a day earlier, a week earlier, or a month ago. Rather than re-run and sample broadcasts for loudness levels, the operator enjoys immediate assurance of compliance. In both compliance and ad verification applications, operators import the daily as-run logs of all ads into the logging system. These boundaries are paired with the logged content to yield loudness of all aired assets. This information simplifies the location of potential problem areas in logged content and makes it easy to respond to a consumer complaint or regulator query. The operator can very quickly locate and export both audio and video. Should a viewer complaint or regulatory query demand it, the operator can use the Volicon Observer’s browser-based interface to navigate quickly through logged content to the ad in question and subsequently export both audio and video, with the real-time loudness parameters burned into the video, into an unambiguous A/V affidavit. By combining the recorded content, the as-run-log from the automation, and loudness capabilities, the logging system with loudness monitoring enables easy and accurate downstream measurements while providing a simple and convincing affidavit of compliance. What loudness monitoring capabilities are critical today? Effective loudness measurement requires a system capable of measuring AC-3 dialnorm levels, as well as the appropriate loudness specifications and regulations for a given region or country. For most operators, this will demand a system that accommodates one or more of these broadly accepted standards or specifications: ITU BS.1770-3, ATSC A/85 RP 2011 and 2013, EBU R128 (Tech 3341/2), or ARIB TR-B32. This would require being able to perform ungated measurements, gated measurements, and dialog power (ATSC A/85 anchor element), as well as simultaneous 5.1 and 5.1 downmix measurement. To be fully compliant, a loudness meter should also measure true peak and loudness range (LRA) from the R128 recommendation. It is also critical that the measurements can be applied on logged content so that precise boundaries and measurement are ensured. Because the measurements are logarithmic, even a small error in time alignment (0.5s) of a commercial boundary could create an error of more than 1dB for a short- duration commercial. providers in an ambiguous position of choosing 5.1 only, stereo only, or the louder of the two to use to level the content. As there are no penalties for commercials that are too quiet, you may see providers level according to the loudest. Additionally, for real-time troubleshooting — or for performing loudness measurements on commercials when the operator does not know the location of the commercial boundaries because he or she lacks access to the as-run log — it is critical that multiple loudness measurements can be performed simultaneously in parallel. (Such measurements might include 10s, 15s, 20s, 30s, 60s, and 120s durations continuously, every 100ms, in sliding windows.) These measurements make it easy for cable to verify compliance of ads for processes such as loudness spot checks without the need for manual recreation of as-run logs from the broadcaster. Because mixing techniques can cause a difference of [+3, -6] on the stereo downmix relative to the 5.1 loudness measurement, this issue has brought many mixing techniques into the spotlight. It is not uncommon to see L, R, and C all contain the same content in a 5.1 dialog mix. The result is a downmix that is 2.8dB hotter and, if left unlevelled, subject to abuse by advertisers. However, penalizing certain track mixes is also perceived as unnecessary interference in the creative process and is slowing resolution of this issue. How are service providers addressing loudness in both surround (5.1) and stereo (2.0) downmix? Because loudness across both 5.1 and the stereo downmix cannot be properly fixed by simply remixing at a different level, this area of compliance is evolving more slowly than others. To be clear, this is not about the 2.0 downmix supplied with the 5.1 track, but rather about the 2.0 downmix that is created by downmixing the 5.1 track in the consumer’s home. Some regulators are, prudently, choosing to regulate the stereo downmix rather than regulate the 5.1. In this case, the asset’s loudness is only measured and leveled based on the stereo downmix. This is a very practical approach to this challenge, and it ensures a simple solution while optimizing the experience for 85 percent of the consumers of 5.1 content. It also makes the solution easy for broadcasters by clarifying the measurement basis for loudness (and subsequent leveling or control mechanisms). Other regulators (ATSC) have only noted that the 5.1 downmix should also be measured but are not specific regarding compliance. This is leaving service ASK OUR EXPERTS What steps are you taking to assure that your monitoring solution stay in step with global standards and formats? We continue to push for recommended practices and legislation that ease compliance efforts so that time and energy can be spent on enhancing quality of the A/V stream and not on interorganizational friction. (Regulators could, for example, mandate the availability of sampled historical as-run logs that would facilitate automated compliance verification for 24 hours of content and skip a lot of error-prone manual processes.) Volicon participates in global loudness standards bodies and, due to our background in compliance logging, frequently consults with regulators all around the world. This gives Volicon early insight into key measurement and compliance issues and practices, ensuring that we can incorporate them into our product offering. Because Volicon is extremely active in the development and testing of emerging standards for loudness and other aspects of broadcasts, we are well- positioned to adapt our Observer line to meet the current and future requirements facing today’s service providers. POST YOUR QUESTION ONLINE: Search ‘tvbay’ Tel. +44 (0)1635 237 237 Email. questions@tv-bay.com TV-BAY MAGAZINE: ISSUE 83 NOVEMBER 2013 | 49