OTT Can Use Dolby Vision to ‘Surpass’ Broadcast, Blu-ray, Dolby Says

Dolby Vision is a way for over-the-top (OTT) providers to “surpass broadcast and Blu-ray,” which have yet to prove a content pathway to next-gen premium content, said Pat Griffis, executive director-technology strategy in Dolby’s office of the chief technology officer, during a press demo at Dolby’s New York offices. OTT providers “are in a position to deliver this now,” he said of Dolby Vision, a suite of technologies designed for the video chain from content creation through playback on a TV.

Dolby used its New York offices as a demo venue for Dolby Vision, which has been held back by the chicken-or-egg dilemma of studios not willing to commit resources to producing content if TVs aren’t in homes to reproduce it, Griffis said. That scenario changed in Las Vegas when TV makers Sharp, Vizio and TCL showed prototypes of TVs that can play back Dolby Vision content. Streaming content partners include Microsoft Xbox Video, Amazon Instant Video, Netflix and Vudu, Griffis said. With Dolby Vision as a way for content providers to generate additional revenue from a premium offering, “Wouldn’t it be ironic if OTT became the premium service provider?” he said.

Dolby is positioning Dolby Vision as both an HD and Ultra HD technology, but it wants its technology deployed now rather than waiting for the UHD TV market penetration to occur. “We think Dolby Vision is the icing on the UHD cake,” Griffis said, but “you can do it with HD.” Dolby Vision is a suite of technologies that allow filmmakers to create a digital video master and deliver it to consumers, Griffis said. The company’s OTT partners are interested in the technology because “they could do this today,” he said, while a standard for next-gen Blu-ray is still in the discussion phase.

Griffis demoed content provided by filmmaker Steven Spielberg to showcase the additional brightness and color capabilities of Dolby Vision in the HD world. Differences in color reproduction and accuracy were impressive, albeit on $40,000 reference 1080p LCD displays with a nit rating of 4,000 compared with consumer-grade TVs limited to 100 nits of brightness. In a side-by-side comparison of Dolby Vision content and Blu-ray content, Griffis pointed out where colorists were able to preserve a brighter sun, more realistic shades of yellow on a flower and detailed stratus clouds in a sky that were washed out on the Blu-ray as a tradeoff to fully capture detail of the girl in the scene. “If you give the 100 nits to the cloud the girl will get darker, so the girl gets 100 nits and the clouds go away,” he said. “No amount of stretching will bring back detail that’s no longer there,” he said.

Dolby’s ambitious target is to “design for the human eye” by delivering more brightness, color and contrast. Today’s video production infrastructure is constrained by the limitation of video reproduction gear in the cinema and at home, he said. “We're a far way from what we know human beings would prefer to see,” he said, citing research the company did in its Sunnyvale, Calif., labs using a display it created that was 200 times brighter than today’s TVs. Dolby created test material where subjects could adjust and dictate how bright they wanted the sun to be. In the test, rather than technology dictating what consumers could do, Dolby asked consumers what their preferences would be. “What should we really be designing for if technology isn’t a limitation?” Griffis asked.

Griffis said the film industry has “lived in a box,” accepting the limitations of technology as it has always been. “The real design target is the human eye,” he said. Toward that end, Dolby is working with “all six studios” to create a standard around the “perceptual quantization curve.” A Dolby spokeswoman told us the company doesn’t have any additional information to share on the quantization curve at this time.

Scott Miller, a senior member of Dolby’s technical staff, in an article printed by The Society of Motion Picture & Television Engineers, described the quantization curve as a solution to limitations of current signal coding methods as TV displays become more advanced. “With bit-depth limitations set by industry standard interfaces, a more efficient coding system is desired to allow image quality to increase without requiring expansion of legacy infrastructure bandwidth,” Miller said in the abstract. “A good approach to this problem is to let the human visual system determine the quantization curve used to encode video signals. In this way, optimal efficiency is maintained across the luminance range of interest, and the visibility of quantization artifacts is kept to a uniformly small level."

For OTT providers to deliver Dolby Vision, they would encode a base layer in the same way they do for the AVC format for content stored in the cloud, he said. They would send an additional stream with Dolby Vision information, he said. The Dolby Vision solution in compatible TVs from partner companies will take the two streams, decode them and give the kind of image displayed in the demo, he said. A TV plays the “legacy stream” and ignores the Dolby stream, he said. A video player such as Amazon or Vudu with Dolby Vision software would be able to “decode the additional information, combine the two streams and output it to make the Dolby Vision picture,” he said. “All the OTT vendors want a backward-compatible approach because they have petabytes of content sitting in the cloud already, and this way they can offer a premium tier of service,” he said.

In the pursuit of “better pictures” by getting rid of “the big squeeze” of compressed video, three elements are required, Griffis said: more pixels for spatial resolution, faster pixels and “better pixels” that deliver whiter whites, blacker blacks and more and brighter colors, he said. Dolby, he said, is “uniquely positioned” to provide a solution for better pictures because “we have consumer partners and understand how content gets distributed, we know the tools and chip vendors and we've been studying the entire ecosystem end to end to address this problem,” he said. Dolby Vision is applicable both to OTT and Blu-ray playback, he said.