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Dolby Vision gets ready for prime time: super-bright pictures set to arrive on TVs later this year

Tom Morgan
3 Sep 2014
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We get an early look at Dolby's next-level picture tech, which gives TV picture brightness and colours a massive boost

Dolby has been at the forefront of of both film and home cinema sound for years, but to date has focused on pictures in a strictly behind-the-scenes way. That looks set to change later this year when the company's ultra-bright Dolby Vision picture technology finally makes it out of the back room and into homes.

With several TV manufacturers onboard, including Philips (which is set to reveal its first Dolby Vision set at IFA later this week), Dolby Vision TVs are due to launch in North America before Christmas, bringing screens capable of 200 times brighter pictures and with 4000 times more contrast than a regular LCD set - meaning significantly more dynamic range and brighter colours.

We got a chance to see how Dolby Vision will work in the home ahead of the IFA show in Berlin, and heard from Dolby's VP of consumer imaging Roland Vlaicu on what to expect when the technology arrives.

Today's TVs are designed to handle 100nit signals. The rec709 display standard all broadcast and recorded video is shown in was designed for low brightness CRT monitors in the 1990s - despite the fact modern LCD, plasma and OLED sets are physically able to deal with much more. It can either show saturated colours or bright light, but not both.

According to Vlaicu, this stripping down of information and losing colour, contrast and visual range could be seen as "a big squeeze", where the signal is the bottleneck to a better picture - one Dolby Vision aims to remove.

THE TECHNICAL DETAILS

Dolby Vision content will initially be mapped to the P3 digital cinema colour gamut and produce 4,000nit images, but the system and container will eventually support rec2020, 10,000nit footage. It can be delivered over HDMI, with no changes made to the HDMI specification, which should mean there's one less barrier to getting it into the home.

That's not to say there aren't technical hurdles. Dolby Vision content is encoded as 12bit video, with an H.264 or HEVC codec extension to allow the 20% extra bandwidth to be decoded by the display. The extra metadata must be decoded by dedicated hardware, meaning existing TVs aren't compatible, but adding a chip that could do it would be all that's required.

DOLBY VISION ON A REFERENCE DISPLAY

The demo footage we were shown used Full HD, 24p content encoded for Dolby Vision, although all Dolby Vision TVs coming later this year will be 4K. The footage, shot on Arri Alexa cameras in uncompressed RAW video, was colour graded for Dolby Vision. On a Dolby PRM4200 professional colour grading monitor, renowned for its colour accuracy among film industry colourists but built for rec709 content, the footage looked bright and colourful. Played side by side with a Dolby Vision TV, however, the differences were incredible: 

The panel on the left produced brighter, more vivid colours than the old reference screen, while at the same time showing brilliantly bright sunshafts and retaining detail in the cloudy sky. The precision of the highlights and increased dynamic range give the impression of more resolution, despite the fact both images are displaying a 1080p source.

SIMULATED DOLBY VISION

We were also shown what an existing high-end TV, fitted with a chip that can decode the signal, could feasibly be capable of. Dolby algorithms, designed on a model-by-model basis, will know what the panels are capable of, then compact the original signal down to suit the display based on metadata contained within it.

Where the brightest areas would be lost from the signal on a traditional TV seen on the left, the retrofitted set on the right was able to produce an impressively bright and colourful image with much darker blacks. It wasn't quite up to the same standard as the native Dolby Vision set, but it came significantly closer than a standard TV.

Of course, content doesn't have to be filmed with Dolby Vision in mind for it to support the technology. The fireworks, crystal chandeliers and glitter in one scene from The Great Gatsby stood out on the Dolby Vision enabled set in a way that was lacking on the traditional panel, with brighter whites giving the impression of greater detail.

THE FINAL HURDLE

Although there's no need to refilm, Hollywood studios will have to re-colour grade their existing content, which then needs to be encoded in a specific format to support the technology. It's a time-consuming process that needs to be done for every piece of footage before it will use Dolby Vision effectively.

Streaming video will be the first path to market - according to Dolby it's the simplest way to encode and deliver content. Smart TV apps with Dolby Vision enabled will be running on the TVs that support it, with several dozen films expected to launch with the service.

North America is first on the list, as Dolby would need to equip other regions with the colour grading tools before they can turn locally produced films into Dolby Vision content. The company is also working with broadcast camera manufacturers to allow live shooting in Dolby Vision, but until a broadcast standard is finalised this won't be arriving any time soon.

Even so, we're optimistic that once the technology is in homes, the content won't be far behind. We're almost there with 4K thanks to streaming services like Netflix, and high dynamic range video may be next on the list. Hopefully we'll be bringing you a review of the first Dolby Vision enabled TVs towards the end of the year.

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