The newly released HDMI 2.0 specification includes a host of new features that will enhance the viewing experience for the next generation of HDTVs, including support for ultra high-definition (HD) / 4Kx2K video, consumer electronic control (CEC) 2.0 for unified remote control functionality, and multi-view video and multi-stream audio. SoC designers must understand HDMI 2.0’s new consumer-friendly features to offer the ultimate home theater experience, as well as the specification’s enhancements over the 1.4 version.
In developing the HDMI 2.0 specification, the HDMI Forum’s main objective was to support an ultra HD experience with 4,096 x 2,160 pixels (4K x 2K) at 60Hz frame rate. Supporting this resolution and frame rate allows viewers to watch video on very large screens with high-definition clarity without any flicker. In addition, the HDMI Forum took the existing install base into account, one that has been established over the past 10+ years. Close to 100 percent of digital home multimedia devices offer HDMI connectivity, and any addition of a device featuring the latest HDMI technology must co-exist with devices using previous HDMI technology. The HDMI 2.0 specification was developed with this in mind, and includes mechanisms to ensure backwards compatibility including using the same hardware connector and cables
The key enhancement in the HDMI 2.0 specification is the amount of total bandwidth transferred has increased from 10.2 Gbps to 18 Gbps. With this increase in bandwidth, consumers can enjoy an improved visual experience in terms of high screen resolution (4K x 2K) for clarity, high frame rate options (60/120/240 Hz) for smooth images, multi-view video, multi-stream audio for special applications and standardized remote control functionality (CEC 2.0) for overall ease of use.
Ultra HD in 4K x 2K video format
HDMI 2.0 offers 4K x 2K (or just “4K” for short) video formats at 60Hz bandwidth and 24-bit color for an ultra HD experience. The 4K frames contain greater than four times the pixels as compared to a 1080p frame, as shown in Figure 1.
|Figure 1: Ultra HD in a 4Kx2K frame offers 4X as many pixels than Full HD (1080p), for a more realistic viewing experience|
An ultra HD image in a 4K video frame offers a wider view than a quad HD frame. A 4K frame denotes the very specific resolution of 4,096 x 2,160 video pixels, which is the resolution of most 4K recordings. A quad HD frame has a resolution of 3,840 x 2,160 video pixels, which is slightly lower than the 4K frame and is exactly four times higher than the full HD resolution of 1,920 x 1,080.
Although 4K video frame support was announced in HDMI 1.4 in 2009, the frame rate was limited to 30Hz, since the maximum defined bandwidth of HDMI 1.4 was 10.2 Gbps. However, consumers have found that a 30Hz frame rate is not sufficient for certain content types (e.g., sports). As a result, a 30Hz frame rate does not present a continuous image to the human eye and appears to flicker on the screen. With HDMI 2.0’s increase in bandwidth to 18 Gbps, the frame rate can now double from 30Hz to 60Hz and is much better suited for content with fast motion.
21:9 frame format
The CEA-861-F specification, referred to in the HDMI 2.0 specification, includes 64:27 aspect ratio formats. Usually known by its marketing term “21:9,” this format allows the transmission of original content in 21:9 formats over HDMI connections without requiring image manipulation in the TV.
Most current TVs support an aspect ratio of 16:9. The new HDMI standard adds support for 21:9 displays because most motion in life takes place on a horizontal plane, rather than vertically. Interestingly, for many years it has been standard practice to shoot movies in the 21:9 format, so unlike 3D, a lack of content will not inhibit the adoption of 21:9 by the consumers.
Although the market is dominated by 16:9 TVs, some manufacturers began offering 21:9 TVs prior to the advent of HDMI 2.0 specification. This aspect ratio allows displaying content recorded in cinema formats without black bars at the top and bottom of the screen. To fill the screen, the original 16:9 content is manipulated by expanding the image horizontally, and then vertically cropped (to remove the black bars) and expanded. The end result is close to the cinema format; however, the quality is not increased due to the scaling process.
Consumers find it very frustrating that electronics manufacturers haven’t worked together to standardize the remote control. Each consumer electronics manufacturer has its own proprietary Bluetooth link for its remote control system that includes various optional features and will not interoperate with equipment designed by other manufacturers. The universal remote controls that are available on the market today tend to be difficult to use, require awkward setup routines and sometimes only have the ability to control a subset of equipment features. The result is that most homes have multiple remotes to operate their DVDs, TVs and set-top boxes.
As an alternative to proprietary remote technology, HDMI 2.0 has upgraded the Consumer Electronics Control (CEC) functionality to version 2.0, which defines a set of operational codes to enable true universal remote controls. Once instantiated, CEC 2.0 lets consumers control up to 15 CEC-enabled devices, each connected through HDMI, by using only one of their remote controls (for example, controlling a television set, set-top box, and DVD player using only the remote control of the TV). CEC 2.0 enables greater integration and interoperability between HDMI devices of different brands, greatly enhancing the user experience and enabling seamless operation between devices.
Multi-view video & multi-stream audio
HDMI 2.0 supports multi-view video and multi-stream audio mode, which consists of two separate video/audio channels that let viewers in slightly different positions enjoy different images. Multi-view mode works a little like 3D TV – using overlapped polarised images that appear distinct when viewed from different angles.
Multi-view video and multi-stream audio features in the HDMI 2.0 specification offer interesting use cases in the gaming and automotive segments. They allow two independent video and audio streams for two people, as shown in Figure 2. For example, in a gaming application, when two players are competing against each other, each player needs to view the screen from his own position. Similarly, in an automotive application, a driver needs to view the GPS/map data while the passenger may want to watch a movie at the same time. Finally, multi-stream audio supports true “surround sound” for high-end home theater systems with state-of-the-art audio setups.
|Figure 2: Applications for multi-view video and multi-stream audio include automotive and gaming applications|
Selection criteria for HDMI 2.0 IP
The key features enabled by HDMI 2.0 center around the increase in bandwidth that in turn allows a greater number of pixels to support an ultra HD experience. Commercial IP solutions must support the plethora of new features of HDMI 2.0 that have been architected for premium home theater systems. The expansive list of HDMI 2.0 features is listed below:
In addition, ideal IP solutions are more than just the hardware netlist. Design teams need the PHY, controllers, verification IP, software, operating system drivers and emulation kits. By having a comprehensive IP solution, design teams will be able to integrate their HDMI 2.0 designs faster and with less risk. Learn more about the features available in HDMI 2.0 IP by downloading the white paper, “How HDMI 2.0 Will Enrich the Multimedia Experience.”
Synopsys is the first IP vendor to announce availability of HDMI 2.0 IP, and has several design wins and test chips available in 28-nanometer technology nodes. The Synopsys DesignWare HDMI solution includes a complete set of software drivers for the Linux platform, which reduces designers’ software development time from weeks to hours and accelerates the time-to-market for products incorporating HDMI 2.0 technology.
Manmeet Walia is a Senior Product Manager for Mixed-Signal PHY IP at Synopsys. He has over 12 years of experience holding product marketing, product management and system engineering positions covering ASSP, ASIC, and IP products for broad range of applications. Manmeet holds a Master of Science degree in Electrical Engineering from the University of Toledo, and an MBA from San Diego State University.