New Developments Emerge At SMPTE Technology Committee Meetings

The Society of Motion Picture and Television Engineers (SMPTE) holds quarterly meetings of its Technology Committees (TC), and the latest of these took place in December 2014, when nine SMPTE TCs and 12 subgroups gathered at The Walt Disney Studios in Burbank, California. Alan Lambshead, SMPTE Standards Vice-President, reports.

More than 100 SMPTE members from all over the world attended in person, while an equal number participated via remote access. Their TC meetings resulted in a number of notable developments.

High Dynamic Range (HDR) Video Projects – The topic of HDR has gained importance with the recognition that the next step beyond high definition television (HDTV) requires improvement beyond pixel count. Improvements to parameters such as colour gamut, displayed dynamic range, frame rates, and electro-optical transfer function all contribute to the improved viewing experience that is needed to justify launching new services.

SMPTE now has a Study Group (SG) compiling a report on the HDR ecosystem, and a new project is set to define dynamic metadata for colour transforms of HDR and wider colour gamut images.

Two SMPTE HDR projects have recently published two new standards: 'Standard (ST) 2084 – High Dynamic Range Electro-Optical Transfer Function of Mastering Reference Displays' and 'ST 2086 – Mastering Display Colour Volume Metadata Supporting High Luminance and Wide Colour Gamut Images'. A third document in this set, 'ST 2085 – Color Differencing for High Luminance and Wide Colour Gamut Images', is now under development.

High Frame Rate (HFR) Projects – From the SMPTE meetings arose a new project that will create a standard specifying time address for HFR and its data structure in the ancillary data space. The standard will be extensible to cover rates of up to 960 frames per second (fps).

Video Compression (VC) Standards – SMPTE has standardised five VC standards: VC-1 to VC-5. Current work on VC standards includes the following:

Development of a suite of documents defining the VC-5 compression system (developed from a GoPro system). Two parts of the suite have been published, and two more are close to publication. Current work has switched to a standard defining VC-5 mapping in the Material eXchange Format (MXF) generic container. Three additional documents are planned for the suite.
The addition of 'image resolution independence' to the list of VC-3 capabilities through the revision of ST 2019-1 and the inclusion of new bit patterns for conformance testing in Recommended Practice (RP) 2019-2.

The additions are backwards-compatible, and no current features are deprecated. This is a newly launched project, awaiting the formation of a drafting group. The project proponent explained that the revision would permit pixel resolutions from 1x1 to 16384x16384, with added support for 12 bits, Recommendation (Rec.) International Telecommunications Union (ITU)-R BT.2020 colour space. A separate project has also been launched in TC-31FS to update ST 2019-4 to support this feature in MXF.

Amendment and revision to two VC-2 documents (developed from BBC's Dirac Pro system). One project adds a high-quality profile for archive and production; the other is a clarification of a published VC-2 document.

Cinema Sound Systems Projects – In October 2014, SMPTE published the report 'B-Chain Frequency and Temporal Response Analysis of Theatres and Dubbing Stages', developed by a Drafting Group within this TC.

This substantial report is available here.

A project is also under way to develop a 'Calibration Reference Wideband Pink Noise Signal and Test File'. Examination of various 'reference' noise files has revealed inconsistency in both root mean square (RMS) and peak amplitude values. This group will create a pink-noise calibration standard and produce a reference pink-noise .wav file and a digital cinema package (DCP) containing the file. The pink noise defined in ST 202:2010 and RP 200:2012 will be used, and the new standard will specify the algorithm used to generate the pink-noise file. The draft standard and the signal-generation algorithm are well-advanced. Work in the past quarter has focused on setting a level (around -18.5dbFS) that demonstrates good agreement with Dolby DMU noise.

Another project group is developing the RP 'Digital Cinema Sound System Setup and Calibration'. The TC also has a Working Group (WG) on the interoperability of immersive sound systems in digital cinema. Its goal is to standardise a single object-based distribution file format and related protocols for interoperable playback into a variety of theatre speaker configurations. Current WG projects are focused on immersive audio metadata.

Open Binding Technology for Persistent Content Identification in Audio/Video (A/V) Essence – Work on open binding technology for persistent content identification in A/V essence has its foundations in the 'Open Binding of IDs to Audiovisual Essence Report', which is available here.

The project will develop an open binding technology standard for embedding end-to-end persistent content identifiers into audio/video essence in a way that survives processing, compression, and distribution. The group's first task is to draft a request for proposals (RFP) for technology that could be the basis for the standard.

Network Based Synchronisation for the Professional Broadcast Environment – Two documents defining a system for distributing synchronisation packets over a data network are nearing publication. 'ST 2059-2 – Precision Time Protocol SMPTE Profile for Time and Frequency Synchronisation in a Professional Broadcast Environment' defines the behaviour of the master. 'ST 2059-1 – The SMPTE Epoch and Generation and Alignment of Interface Signals' defines the behaviour of the slaves, allowing them to create any synchronised video, audio, or time code signal.

The system uses a SMPTE profile for the Precision Time Protocol (IEEE 1588 v2) that provides acceptable lock-up time, jitter, and accuracy while providing metadata that allows time code generators to make adjustments for time discontinuities such as leap seconds and the change from daylight savings time to standard time.

Participating in the SMPTE Standards Process: SMPTE is a professional membership association and the preeminent leader in the advancement of the art, science, and craft of the image, sound, and metadata ecosystem, worldwide. An internationally recognised and accredited organisation, SMPTE advances moving-imagery education and engineering across the communications, technology, media, and entertainment industries. SMPTE is the only organisation that connects the areas of motion-imaging research, standardisation, education, and business success. Since its founding in 1916, SMPTE has published the SMPTE Motion Imaging Journal and developed more than 800 standards, recommended practices, and engineering guidelines.

Altera in San Jose, California, will host the next quarterly standards meetings, from 2-5 March. Randwick Technical and Further Education (Randwick TAFE) will host meetings from 7-10 July in Sydney, Australia, in conjunction with the biennial event, SMPTE15 Conference and Exhibition.

Anyone interested in the standards process is welcome to join the SMPTE standards community. A detailed report from the December meetings and more information about participating is available here.

The article is also available to read in BFV online.

(IT/JP)