Effect of Dolby Volume on broadcast production requirements clarified
January 25, 2007
At the recent Consumer Electronics Show (CES) in Las Vegas, Dolby Laboratories offered the first demonstration of Dolby Volume, a consumer technology aimed at solving viewer annoyance with inconsistent volume. To learn whether this coming technology will affect broadcast production requirements, we spoke with Rocky Graham, Dolby's director of broadcast products. Graham was emphatic that broadcasters and content producers should not view Dolby Volume as a substitute for current metadata encoding techniques. Rather, the nascent technology is designed to normalize volume in non-Dolby Digital sources running through the consumer's TV.
"It really doesn't change things for people in production and for broadcasters themselves. It does not change what they need to be providing on their signals. Dolby Volume does not take the place of metadata — dialnorm metadata for instance," Graham said. Dialnorm (dialogue normalization) is a metadata encoding protocol within Dolby Digital used to control loudness. "Dolby Digital has always included this mechanism," he explained, "and it is used by broadcasters to control the reproduce level in the home. The intention of Dolby Volume, on the other hand, is to address the other signals that are available to consumers and do not include Dolby Digital encoding."
As examples of audio sources that will benefit from Dolby Volume, Graham cited analog broadcast, satellite channels not encoded in Dolby Digital and gaming consoles, among others. Dolby Volume will normalize these sound sources. Broadcast content properly encoded in Dolby Digital, conversely, will be unaffected in the home.
The message to broadcasters is clear: If anything, the coming introduction of Dolby Volume makes the proper use of dialnorm parameters all the more critical in producing Dolby Digital content for broadcast. Dialnorm allows broadcasters to properly control loudness parameters at the source, while allowing production engineers to monitor the end result of any processing to ensure the material will sound the way it was intended.
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