AES London 2011
Paper Session P5
P5 - Production and Broadcast
Friday, May 13, 14:00 — 17:30 (Room 4)
P5-1 Frequency Weighting and Ballistics for Program Loudness Modeling—Ian M. Dash, Australian Broadcasting Corporation - Sydney, NSW, Australia; Benjamin Smith, Densil Cabrera, University of Sydney - Sydney, NSW, Australia
There has been both experimental and anecdotal evidence that the low-frequency performance in the ITU-R Recommendation BS.1770 program loudness measurement algorithm could be improved. A listening test with an emphasis on low frequency content was therefore conducted. An attempt was made to analyze the results in octave bands by multiple regression, but larger than expected variability precluded any useful outcome from this method. A simpler regression analysis was therefore performed using several fixed weighting curves and asymmetric integration with a range of time constants. Although the results largely support the present low frequency weighting curve, they also indicate that asymmetric integration provides better program loudness assessment than symmetric integration or high level gating.
Convention Paper 8341 (Purchase now)
P5-2 Evaluation of Live Meter Ballistics for Loudness Control—Scott Norcross, Communications Research Centre - Ottawa, Ontario, Canada; Félix Poulin, CBC/Radio-Canada - Montreal, Quebec, Canada; Michel Lavoie, Communications Research Centre - Ottawa, Ontario, Canada
The broadcast community is transitioning from practices that revolved around audio peak normalization to one where the focus is on loudness consistency. Central to this effort is the loudness measurement algorithm described in ITU-R BS.1770. To assist in the mixing of audio that targets specific long-term loudness levels a need has been identified for some form of loudness-based live audio metering. The EBU has proposed meter specifications to indicate “momentary” and “short-term” loudness whose ballistics are defined, respectively, by a 400 ms and a 3000 ms integration window. In parallel with the EBU efforts, the CBC/Radio-Canada, in collaboration with the CRC, has been studying since 2008 various loudness meter ballistics that would be suitable in a production environment. This paper reports on a series of tests carried out by the CBC/Radio-Canada where various momentary meter ballistics wee evaluated it was found that an IIR-based meter ballistic with a 400 ms time-constant was preferred.
Convention Paper 8342 (Purchase now)
P5-3 Adaptive Dynamics Enhancement—Martin Walsh, Edward Stein, Jean-Marc Jot, DTS, Inc. - Scotts Valley, CA, USA
Modern recordings are being mastered with more and more aggressive dynamic range compression in an attempt to generate content that is louder than previous releases. This can often lead to large discrepancies in perceived loudness between tracks that were mastered at different periods of recent history. A commonly proposed solution to this problem involves the use of loudness normalization. While such normalization techniques help to reduce discrepancies in loudness, they cannot resurrect dynamics that were removed due to extreme levels of dynamic range compression. This paper outlines a technique for restoring the dynamics of modern music by continuously monitoring transient signal behavior together with the associated dynamic range levels. When dynamic range compression is likely, transients are restored to levels that are more expected for the type of material being played.
Convention Paper 8343 (Purchase now)
P5-4 Describing the Transparency of Mixdowns: The Masked-to-Unmasked-Ratio—Philipp Aichinger, Medical University of Vienna - Vienna, Austria University of Music and Performing Arts Graz, Graz, Austria; Alois Sontacchi, University of Music and Performing Arts Graz - Graz, Austria; Berit Schneider-Stickler, Medical University of Vienna - Austria
In this paper a model that predicts the transparency of mixdowns is proposed. The Masked-to-Unmasked-Ratio relates the original loudness of an instrument to its loudness in the mix. In order to assess this new measure a listening test is conducted. It is shown that instruments with a Masked-to-Unmasked-Ratio of 10% or smaller are critical in mixdowns because most of them cannot be identified adequately. The newly suggested model is to be used in automatic mixdown algorithms and as an evaluating measure in future development whenever masking scenarios are to be described.
Convention Paper 8344 (Purchase now)
P5-5 The "Digital Solution”: The Answer to a Lot of Challenges within New Production Routines at Today’s Broadcasting Stations—Stephan Peus, Georg Neumann GmbH - Berlin, Germany
The introduction of networked production systems allows a very actual, topical, and efficient workflow especially within broadcast and TV applications. As a result production is moving closer to editorial work. Sound editing such as voice-over, etc., has to be done more and more by editors who naturally don’t have that special knowledge as a sound engineer. Life recordings and interactive TV in future will call for further steps to simplify the production processes and to enhance reliability. We will explain practical examples of challenges from daily production routines, will give answers to solve the problems by using digital technology, and will show the effects on a more simple and reliable workflow.
Convention Paper 8345 (Purchase now)
P5-6 Automatic Mixing and Tracking of On-Pitch Football Action for Television Broadcasts—Robert G. Oldfield, Benjamin G. Shirley, University of Salford - Salford, UK
For the television broadcast of football in Europe, the sound engineer will typically have an arrangement of 12 shotgun microphones around the pitch to pick up on-pitch sounds such as whistle blows, players talking, and ball kicks, etc. Typically, during a match, the sound engineer will increase and decrease the levels of these microphones manually in accordance with where the action is on the pitch at a given time to prevent the final mix being awash with crowd noise. As part of the EU funded project, FascinatE, we have developed an automatic mixing algorithm that intelligently seeks key events on the pitch and turns on the corresponding microphones, the algorithm picks out the key events and automatically tracks the action eliminating the need for manual tracking.
Convention Paper 8346 (Purchase now)
P5-7 High Quality “Radio” Broadcasting over the Internet—David Errock, Wave Science Technology Ltd. - London, UK
Broadcasting audio over the internet has dramatically improved the experience for listeners, including removing the geographic boundaries of terrestrial transmission, allowing playback on portable devices and time-shifting content. Internet audio has primarily increased choice with traditional broadcasters now competing alongside “internet only” music stations. Internet distribution can also increase the audio quality, beyond that of terrestrial and satellite transmission channel constraints; unlike video streaming, which is of lower perceived quality than traditional transmission. With the sustainable data capacity of internet connections increasing, lossless audio can be streamed live to the consumer. This paper discusses the issues relating to these distribution techniques and the challenges that will be experienced by the broadcasters, the distribution network, receiver manufacturers, and listeners.
Convention Paper 8347 (Purchase now)