Two pioneering efforts in cinema audio standards are nearing conclusion, both headed by Brian Vessa of Sony Pictures Entertainment. The first effort reviews the measurement techniques used for qualifying the B-chain, which is cinema-speak for everything in the audio signal path between the digital cinema server and our ears. The other is the introduction of individual audio channel labels in the digital cinema package. Both are significant, but in different ways.
The B-chain measurement effort is an opportunity for a younger generation to validate (or invalidate) what an older generation did 30 years ago. It ‘s a good time to do this, as in another 10 or 15 years, there will be far fewer of the older generation around to explain why things ended up as they have. The most important “discovery” of the group is what everyone knew all along: what measures well does not necessarily sound good. Such revelations open the door to mysterious and mystical techniques and systems that claim to be better than the rest, with little to stand on other than “they sound good.” After all, this has been the core premise behind the high-end consumer audiophile industry since it was born.
What SMPTE does so well for cinema sound is to offer it a place in the world of professional presentation by giving it a solid foundation. The B-chain Study Group wants to take this further. It proposes a new series of standards, recommended practices, and engineering guidelines provide an even more formal foundation for cinema sound than exists today. The Study Group even suggests that SMPTE get into the cinema certification business. These are all ambitious proposals. Generation of new standards requires substantial support and contribution from the industry, both financial and labor. But document creation is what SMPTE does well. Creation of a cinema certification program is simply outside of the business scope of the organization. But the point is made that such a service is needed. What was it that the trailer says…”THX is listening”…or something like that?
Brian’s other effort to standardize individual channels labels for audio tracks is also coming to a conclusion. The proposed standards are now in ballot. The method in ballot will perform the job nicely for the world of channel-based audio. (How it applies to object-based audio remains to be seen.) But the work didn’t go as far as your author would have liked. If there is one document in the cinema standards suite that has caused eyes to roll for its inability to prescribe anything useful, it’s ST0428-3 DCDM Audio Channel Mapping and Channel Labeling. ST0428-3 should be placed in the shredder. Your author attempted to take the first step towards this goal when chairing last year’s revision of ST0429-2, the core document for SMPTE DCP. But it was decided that we would wait until the conclusion of the work on audio channel labeling. However, the new audio work includes, rather than discards, ST0428-3. What were they thinking? This will be a prime topic when the ballot comment resolution process takes place.
