Will Ultra HD Blu-ray players have to be connected to the Internet to play 4K discs? How will consumers transfer 4K content from discs to portable devices? Will Ultra HD Blu-ray players play DVDs and CDs? And will players and discs accommodate content created with Dolby Vision high dynamic range (HDR) technology.
The Blu-ray Disc Association (BDA), which promotes the Bluray Disc format, answered these and other questions:
Disc compatibility: Ultra HD Blu-ray players are required to play back 2D 1080p Blu-ray discs, but as is the case with current Blu-ray players, playback of CDs and DVDs isn’t mandatory. Nonetheless, the association expects all 4K players will offer CD and DVD playback, as do all current Blu-ray players.
Playback of 3D 1080p Blu-ray discs is a player option, but you won’t see 3D 4K content on Ultra HD Blu-ray discs. The Ultra HD Blu-ray standard doesn’t include 3D on 4K discs.
Separately, the Ultra HD Blu-ray standard does not require a player to be connected to the Internet to get authorization to play a disc. Studios, however, have the option to remotely store encryption keys, thus requiring an Internet connection. That’s not expected to be common practice, though it could be useful in controlling the distribution of early release discs.
Video performance: The more efficient HEVC codec, combined with higher capacity movie discs (66MB and 100MB compared to Blu-ray’s 25GB and 50GB) will allow for 3,840 by 2,160 resolution compared to Bluray’s 1920 by 1080 resolution. The Ultra HD Blu-ray format will also accommodate 10-bit color versus 8-bit color and high dynamic range (HDR) content. The format supports 100Mbs peak bit rates, compared to Bluray’ s 40Mbps, and frame rates up to 60 fps, up from 24 fps.
Color gamut: Players are required to support the ITU’s BT 2020 color range, which exceeds the DCI-P3 range of colors delivered by digital cinemas, which in turn exceeds the BT.709 gamut that current Blu-ray discs can deliver. Players must also be able to reproduce the BT.709 gamut, which delivers 35 percent of the colors that the human eye can perceive.
TVs capable of displaying 2020 gamut will begin to appear this year and next, the association said. One studio has already released a theatrical movie with 2020 gamut.
High Dynamic Range (HDR): Players must support the baseline 10-bit SMPTE 2084/2086 Open HDR standard, though 4K discs themselves aren’t required to offer HDR content. Optional BDA-approved HDR technologies from Dolby Vision and Philips can accompany 2084 on a disc, but players aren’t required to recognize the Dolby and Philips technologies.
Copy and Export: This optional feature set, previously called Digital Bridge, consists of two main options. First, players can incorporate embedded hard drives to make and store bit-for-bit copies of multiple 4K discs, including bonus content and interactive features. The intent is to make individual movies accessible without requiring people to browse through a stack of discs. Panasonic’s first player, announced for the Japan market, incorporates a 3TB hard drive, though in Japan, Blu-ray players are often combined with cable settop boxes and DVRs. Samsung also plans a model with optional hard drive.
The export part of this optional feature set will let disc purchasers obtain copies of a title for playback on portable devices, if the content provider approves. Consumers, however, won’t be able to transfer a copy from their player’s hard drive directly to a portable device. Instead, consumers will engage with third-party services, as they do now for UltraViolet copies of 2D Blu-ray discs. Only the movie itself, soundtracks, and subtitles will appear in the copy.
Audio: The requirements and options are the same as they are for 2K Blu-ray discs and players.
Other: The spec doesn’t require two HDMI outputs on players, and it allows for BD Live-type interactive content on 4K discs at the content providers’ option.