SMPTE 21DC working groups and project groups met on Nov 30, barely within the reporting window for this month’s report. Several revised documents are on the path for elevation to ballot.
The documents are:
- 429-2 DCP Operational Constraints
- 430-4 Security Log Format
- 430-5 Security Log Constraints
- 430-7 Facility List
- 430-9 KDM Bundle
- 433 Datatypes
The 430 and 433 series documents are revised to correct the trailing slash namespace problem that was reported earlier in this journal. It has taken the whole of 2010 to expose and achieve agreement on solutions for these problems. Assuming the ballots go through successfully, the revisions will be published in Spring of 2011. (This is pointed out to show how long it takes to get even a simple fix through the system.) The 433 Datatypes revision also includes several clarifications requested by users. There should be no impact on production equipment with the changes incurred in the 430 and 433 documents.
SMPTE practice distinguishes between amending a document, and revising a document. Usually one amends a standard when the change is minor. The amendment is published separately, and then incorporated into the standard during its normal 5-year review. One normally revises a standard if there are substantial changes to be made. But it was brought to light in this month’s meeting that there are other reasons for amending documents that define XML schemas. Amendments won’t cause a change in namespace name for the datatype that is defined by the standard in question. What this means is that a unique identifier for the schema would change. The impact of this change could be substantial if the schema is tested by FIPS or the DCI Compliance Test Plan. A change in such XML schema could cause loss of strict compliance, or cause a re-test under strict rules. As this subject was explored, it was decided to move down the amendment route, rather than the revision route, for the 430 and 433 documents listed above.
The 429-2 DCP Operational Constraints document is the core document to the SMPTE DCP packaging format. Clarifications are needed in the provisions for timed text (open and closed subtitles and captions) to address issues that have occurred in production. The major change is the addition of two audio formats to the standard. SMPTE DCP audio does not suffer the problem of Interop audio, and can support a large number of audio formats. Eventually, it is hoped that it will also support individual channel labeling, which will reduce and possibly eliminate the need to specifically describe a new audio format in this document.
The two new audio formats will be a full 16-channel format for “test” purposes. It will not show a specific channel assignment, and exists to support experimentation with new sound formats. The other new format is the 7.1DS surround format introduced by Disney with Toy Story 3.
Your author also chairs the 21DC30 Exhibition Working Group, an impressive title for a group that is carrying only a small load these days. Due to the dwindling need for this group, your author opened the floor to a discussion of disbanding the group. As a result, the March 2011 meeting may be the last for both the 21DC10 Mastering and 21DC30 Exhibition Working Groups. The ad hoc groups that actually perform the document work will continue to meet. The action will reduce the number of groups and increase managerial efficiency for the committee. But it will have no impact on the standards work.
The next meeting of the full 21DC Technology Committee is in Melbourne, Florida on December 8. (Your author didn’t know there was a Melbourne in Florida.)