UHD Blu-ray Capabilities Require Workflow Adjustments
While much or recent press has focused on the rapid growth in OTT, streaming media and digital entertainment, industry watchers shouldn’t overlook that there are some exciting, new things cooking over in physical home entertainment. UHD Blu-ray, the new ultra high definition physical format experienced some strong sales and vibrant sales growth during the 2016 holiday shopping season. According to data cited by the Blu-ray Disc Association, movie lovers snapped up an impressive 1.8 million UHD Blu-ray discs in the United States in 2016, as well as 300,000 UHD Blu-ray players. The disc-to-player attach rate was an impressive 6-to-1, noted the BDA, adding that sales have been three times as fast as the launch of Blu-ray. As consumers are showing increasing interest in UHD Blu-ray, studios are planning to release more titles, more than doubling 2016 release slate with over 250 titles expected in 2017.
To enable our clients to achieve this increase and to service this upcoming release wave, we at Giant Interactive have developed and implemented new processes and workflows to accommodate the new capabilities and technical specifications of this ultra-high definition format. For example, unlike “standard” Blu-ray, the UHD Blu-ray specification supports High Dynamic Range (HDR) and wide color gamut (WCG) , greatly increasing the range of contrast between light and dark images on the screen as well as enhancing the color-space resulting in a much more life-like image. Ultra HD Blu-ray supports a default 10-bit HDR but other optional HDR formats available. For authoring teams, these new features mean that information from mastering needs to be incorporated much earlier in the production workflow, affecting both video compression and authoring processes.
The format also has necessitated an overhaul in menu design to accommodate both the graphics plane’s HD resolution and its visibility against HDR background video. The graphics plane is not in 4K resolution but is instead still in high-definition (1920×1080 ). Upon playback, menu graphics are automatically scaled to 4K (3840×2160) by the player, compelling designers to conceive and create menus that won’t lose integrity with upscaling. The new design also needs to take into account the perceptibility of the menu against both a high dynamic range video, as well as down-converted SDR video, if playback doesn’t occur on a HDR display. Subtitles pose a similar challenge but do not require radical change in creation since most subtitles have a consistent look and usually employ only one or two colors.
As a result of these changes, additional quality checks are required from both the authoring and quality control teams to ensure proper color reproduction and brightness levels. Due to the diverse set of players and televisions and variation of settings in these, images can be rendered differently and can lead to a disappointing consumer experience. UHD displays fall into three broad categories: SDR/HD, SDR/4K or HDR/4K displays, thus quality control reviews must include all three. Complicating matters further, the UHD Blu-ray specification allows for authoring to use one or all three optional HDR-to-SDR technologies or even leave the choice to the playback device, so to ensure good picture quality across all players, televisions, and various settings, quality control must be applied against all of the different color, brightness, and conversion combinations.
Ultra HD Blu-ray Disc configurations also must be adjusted to accommodate the larger data requirements of 4K video and support larger 100 GB, 66 GB, and 50 GB disc capacities and each disc layout must be optimized to maximize player performance. A UHD Blu-ray spec compliant technique first utilized by Giant’s CTO Bhanu Srikanth and her team uses a special logical layout called “dual zone” can be used to accommodate the required higher bitrate, locating that specific high-bitrate video content on the outer area of the disc which enables the player to read more bits at a time. Although this isn’t a dramatic workflow change, it is one which to be considered carefully in the planning stage of authoring since switching to a dual zone configuration at a later stage can have an enormous impact to the project timeline, which may result in shipping delays and street date postponement, which everyone wants to avoid.
Anti-piracy safeguards have also been strengthened with the introduction of AACS 2.0 to the Ultra HD Blu-ray specification. The newly-enabled, advanced features such forensic watermark and correction keys further change the workflow since these affect video encoding, authoring and testing.
While Ultra HD Blu-ray is technically an extension of Blu-ray from a standardization perspective, the expanded capabilities and technical characteristics of the format have necessitated extraordinary changes in the post-production workflow in every phase of the production process, making the authoring process of the two formats dissimilar in a number of ways.
More information about the differences in UHD Blu-ray production can be found in Ultra HD Blu-ray Brings Forth Ultra-Workflow Challenges by Bhanu Srikanth, appearing in the Winter edition of MESA’s M&E Journal.