The subgroups of SMPTE 21DC Technology Committee for Digital Cinema held face-to-face meetings in May in advance of the parent committee’s quarterly meeting scheduled for June 22.
An overview of the committee’s current work:
3-D Subtitling
A revision of SMPTE 428-7 Subtitles to implement the 3-D display of on-screen text has been in development for some time. As work progressed towards establishing the methods and features for displaying text with depth, refinements for the display of 2-D began to emerge from implementers. As the SMPTE subtitle specification has yet to be deployed anywhere but in laboratories, it is important to capture feedback and improve the specification. However, this additional task has added to the workload of the group, increasing the time required to fully develop the revised version of 428-7. A reasonable guess is that the final version will be available early next year.
HFR
A revision of the SMPTE 428-12 Auxiliary Frame Rates document is being prepared for ballot. This is a modest revision, following recommendations made by the 21-DC HFR Study Group last year, focusing on higher frame rates that are achievable with the installed base of equipment.
Immersive Audio-Related
With numerous audio-related study efforts underway in the SMPTE 25CSS Technology Committee intended to provide a basis for an immersive audio standard, 21DC is taking the approach of standardizing the low hanging fruit that could be beneficial in achieving interoperability of future audio systems. One such document under consideration would create a generic track file container that could hold 3rd party proprietary audio and other data. Read: Dolby ATMOS. Another document under consideration describes a synchronization signal and related communication between a main media block and a satellite media block. The synchronization signal could be delivered as an audio channel in the main 16-channel audio track file, or generated as a signal by the main media block. These works are still in early stage development, in the opinion of this author, but could mature quickly if driven hard.
