The June meeting of the SMPTE 21DC Technology Committee took place in Montreal, inconveniently at the end of Cinema Expo in Amsterdam. To no avail, 21DC chairman Dave Schnuelle complained about the timing of the meeting, which was set by Engineering VP Wendy Aylsworth. Not having yet perfected the art of being in two places at once, your author was unable to attend in person. But here’s a recap of events:
The Additional Frame Rates ad hoc group, which pioneered several standards documenting the additional frame rates for picture and audio that may be supported by digital cinema systems, was closed. The group has fulfilled its work, with its final document now going through final reviews prior to publication.
A new SMPTE Registered Disclosure Document (RDD) for Texas Instrument’s Cinelink 2 was published. Cinelink 2 is the link encryption applied to the transmission of picture from 2K server to projector. Years ago, Sony wanted TI to openly publish Cinelink 2. As TI then refused to do so, Sony developed its own method and standardized it, resulting in SMPTE 427 Link Encryption for 1.5 Gb/s1 Serial Digital Interface. However, neither Sony nor TI used the standard, while Cinelink 2 prevailed in the marketplace. Finally, TI came through and published its method. Cynically, just in time, as it’s about to introduce its 4K projector for which Cinelink 2 will not apply.
A new ad hoc group was formed to address audio channel labeling for cinema. This group is further discussed elsewhere in this report.
The one subject of year-long controversy slated for discussion at this meeting was whether or not to change the normative namespace name for DCML in SMPTE 433 Datatypes. As reported earlier this year, S433 normatively defines the namespace name with a terminating “/”, while the informative schema file supplied by SMPTE does not. As several documents relied on the informative schema file, something must change. Either S433 must change, or the other documents must change. In the meeting, 21DC decided that the other documents must change, and that S433’s normative prescription remain unchanged. This affects the published versions of S430-4 Log Record Format Specification, S430-5 Security Log Event Class and Constraints, S430-7 Facility List Message, and S430-9 Key Delivery Bundle, and S433 Datatype (its informative schema file). S430-11 Resource Presentation List, the “RPL” of the CSP/RPL protocol used for closed captions, also requires a change to comply. As a result, S430-11 was posted for 2 week review prior to ballot to incorporate the change in DCML namespace name.
The next meeting of 21DC will take place in September.
