Sound may be 50% of the experience, but picture occupies 90% of the digital composition. Fulfillment companies know this well, as a movie whose versions require different picture track files have a lot more data to manage. Picture track file versions are required when separate 2-D and 3-D versions are released. Additional track files versions are required when different color timings are made available to accommodate screens with higher luminance levels. Still more picture track files are required for 3-D subtitles, which must be “burned-in” with the image. 3-D subtitles are difficult to read if placed at a different depth than that of the subject, and thus require special treatment. Notably, burned in subtitles are not required for 2-D picture, as separately provided timed text is used, occupying a tiny fraction of the digital composition. So it is of great interest to studios that a common timed text method emerge for 3-D subtitling.
Development of a common method been a subject within SMPTE for several years. The fruit of that work is about to surface as documents come forward for balloting as standards. The ballot process should begin this summer, and if lucky, will produce 3-D subtitling standards by the end of the year. Two documents will be revised: SMPTE ST0428-7 DCDM Subtitle, and ST0429-12 DCP Caption and Closed Subtitle.
The most recent draft has markedly improved over the past 6 months. The difficult part of 3-D timed text is that, unlike horizontal and vertical positioning, the depth position of the text is not necessarily static. Make the method for describing variable depth too flexible, and 3-D text rendering engines become too complex. The current draft provides a compact notation that describes variable depth while precluding complicated applications where support for smooth vertical and/or horizontal movement would also be required.
With technical details sorted out, the next hurdle will be implementation in the field. Non-English-language territories will be most affected with the cost of upgrade. It’s expected that TI Series 2 projectors and integrated media blocks will only require software upgrades. Older Series 1 projectors, however, will require use of a stand-alone server having a media block that can render timed text. For many cinema owners, that could be an expensive upgrade.
Studios will have to weigh the value of 3-D subtitles in certain territories. Without a financial incentive to change, an estimated 5000 screens will continue to need burned in 3-D subtitles. With over 70,000 screens in the world, it’s not out of the question that some form of rental credit could be applied to those in need to make this transition happen.