Society of Motion Picture and Television Engineers (SMPTE) 3D Home Entertainment Task Force

There is a need for a single mastering standard for viewing stereo 3D content on TVs, PCs, and mobile phones, where the content could originate from optical disks, broadcast networks, or the Internet. To that end, SMPTE formed a 3D Home Entertainment Task Force in 2008 to work the issue and a standards effort was launched in 2009 via an SMPTE 3D Standards Working Group to define a content format for stereo 3D. The SMPTE 3D Standards Working Group had about 200 participants at press time; the Home Master standard was expected to become available in mid-2010. The group is in favor of a mastering standard for the Home Master specification based on 1920 × 1080 pixel resolution at 60 fps/eye. The specification is expected to support an option for falling back to a 2D image. The standard is also expected to support hybrid products, such as BDs that can support either 2D or stereo 3D displays.

SMPTE’s 3D Home Master defines high-level image formatting requirements that impact 3DTV designs, but the larger bulk of the 3DTV standards for hardware are expected to come from other organizations, such as CEA. Studios or game publishers would deliver the master as source material for uses ranging from DVD and BD players to terrestrial and satellite broadcasts and Internet downloadable or streaming files

As we have seen throughout this text, 3DTV systems must support multiple delivery channels, multiple coding techniques, and multiple display technologies. Digital cinema, for example, is addressed with a relatively simple left–right sequence approach; residential TV displays involve a greater variety of technologies necessitating more complex encoding. Content transmission and delivery is also supported by a variety of physical media such as BDs as well as broadcasting, satellite, and cable delivery. The SMPTE 3D Group has been considering what kind of compression should be supported. One of the key goals of the standardization process is defining and/or identifying schemes that minimize the total bandwidth required to support the service; the MVC extension to MPEG- 4/H.264 discussed earlier is being considered by the group. Preliminary studies have shown, however, that relatively little bandwidth may be saved when compared to simulcast because high-quality images require 75–100% overhead and images of medium quality require 65–98% overhead. In addition to defining the representation and encoding standards (which clearly drive the amount of channel bandwidth for the additional image stream), 3DTV service entails other requirements; for example, there is the issue of graphics overlay, captions and subtitles, and metadata. 3D programming guides have to be rethought, according to industry observers; the goal is to avoid floating the guide in front of the action and instead, to push the guide behind the screen and let the action play over it because practical research shows that people found it jarring when the programming guide is brought to the forefront of 3DV images [13]. The SMPTE Group is also looking at format wrappers, such as Material eXchange Format (MXF; a container format for professional digital video and audio media defined by a set of SMPTE standards), whether an electrical interface should be specified, and if depth representation is needed for an early version of the 3DTV service, among other factors [14]. As we have noted earlier in the text, 3DTV has the added consideration of physiological effects because disjoint stereoscopic images can adversely impact the viewer.

 

3DTV Standardization and Related Activities

Standardization efforts have to be understood in the context of where stakeholders and proponents see the technology going. We already defined what we believe to be five generations of 3DTV commercialization in Chapter 1, which the reader will certainly recall. These generations fit in well with the following menu of research activity being sponsored by various European and global research initiatives, as described in Ref. [1]:

Short-term 3DV R&D (immediate commercialization, 2010–2013)

  • Digital stereoscopic projection
    • better/perfect alignment to minimize “eye-fatigue.”
  • End-to-end digital production-line for stereoscopic 3D cinema
    • digital stereo cameras;
    • digital baseline correction for realistic perspective;
    • digital postprocessing.

Medium-term 3DV R&D (commercialization during the next few years, 2013–2016)

  • End-to-end multi-view 3DV with autostereoscopic displays
    • cameras and automated camera calibration;
    • compression/coding for efficient delivery;
    • standardization;
    • view interpolation for free-view video;
    • better autostereoscopic displays, based on current and near future technology (lenticular, barrier-based);
    • natural immersive environments.

Long-term 3DV R&D (10+ years, 2016–2020+)

  • realistic/ultrarealistic displays;
  • “natural” interaction with 3D displays;
  • holographic 3D displays, including “integral imaging” variants;
  • natural immersive environments;
  • total decoupling of “capture” and “display”;
  • novel capture, representation, and display techniques.

One of the goals of the current standardization effort is to decouple the capture function from the display function. This is a very typical requirement for service providers, going back to voice and Internet services: there will be a large pool of end users each opting to choose a distinct Customer Premises Equipment (CPE) device (e.g., phone, PC, fax machine, cell phone, router, 3DTV display); therefore, the service provider needs to utilize an network-intrinsic protocol (encoding, framing, addressing, etc.) that can then be utilized by the end device to create its own internal representation, as needed. The same applies to 3DTV.

As noted in Chapter 1, there is a lot of interest shown in this topic by the industry and standards body. The MPEG of ISO/IEC is working on a coding format for 3DV. Standards are the key to cost-effective deployment of a technology. Examples of video-related standards include the Beta-VHS (Video Home System) and the HD DVD–Blu-ray controversies.  SMPTE is working on some of the key standards needed to deliver 3D to the home. As far back as 2003, a 3D Consortium with 70 partner organizations had been founded in Japan and, more recently, four new activities have been started: the [email protected] Consortium, the SMPTE 3D Home Entertainment Task Force, the Rapporteur Group on 3DTV of ITU-R Study Group 6, and the TM-3D-SM group of DVB. It will probably be somewhere around 2012 by the time there
will be an interoperable standard available in consumer systems to handle all the delivery mechanisms for 3DTV.

At a broad level and in the context of 3DTV, the following major initiatives had been undertaken at press time:

  • MPEG: standardizing multi-view and 3DV coding;
  • DVB: standardizing of digital video transmission to TVs and mobile devices;
  • SMPTE: standardizing 3D delivery to the home;
  • ITU-T: standardizing user experience of multimedia content;
  • VQEG (Video Quality Experts Group): standardizing of objective video quality assessment.

There is a pragmatic possibility that in the short term, equipment providers may have to support a number of formats for stereo 3D content. The ideal approach for stereoscopic 3DTV is to provide sequential left and right frames at twice the chosen viewing rate. However, because broadcasters and some devices may lack transport/interface bandwidth for that approach, a number of alternatives may also be used (at least in the short term). Broadcasters appear to be focusing on top/bottom interleaving; however, trials are still ongoing to examine other approaches that involve some form of compression including checkerboard, sideby-side, or interleaved rows or columns.