New video compression protocol developed for mobile devices and future 8K displays
The Video Electronics Standards Association (VESA) and the MIPI Alliance announce the finalization and availability of the Display Stream Compression (DSC) Standard, version 1.0.
VESA developed the DSC standard as an industry-wide compression standard for video interfaces, offering visually lossless performance and low latency. DSC has been adopted into VESA's embedded DisplayPort (eDP) v1.4 and into MIPI Display Serial Interface (DSI) Specification v1.2, which are used for embedded display interfaces within mobile systems, including smartphones, tablets and laptops. It is anticipated that the DSC standard will also be used for external display interfaces to computer monitors and televisions.
Increasing display resolution and higher refresh rates present challenges for small-display mobile devices and laptops, as well as large external displays. As display resolutions increase, the interface payload capacity must increase either with more power-consuming bandwidth, video data compression, or both. Displays going beyond 4K resolutions will push the video data rate beyond the current limits of the interface standards. For example, standard 1080p displays require a video data rate of 3.5 gigabits/sec; 4K displays at 60Hz require 14 gigabits/sec; and future 8K displays will require over 50 gigabits/sec. VESA's DSC standard version 1.0 enables up to 66 percent data rate reduction, extending battery life in mobile systems and laptops, while simplifying the electrical interface requirements for future 4K and 8K displays.
"VESA recognized the need for display interface compression in mobile devices to extend battery life without compromising visual quality," said Dale Stolitzka, VESA Display Stream Compression Task Group Chairman and member of Samsung Display America Laboratory. "In addition, on-going development of DisplayPort standards, which includes 8K resolution support, foresaw the need for compression because of inherent limits in the existing display interface cables. VESA realized that compression was becoming a common need in the industry, and that a standard compression coding system could meet these common display interface needs."
The VESA DSC Task Group, in collaboration with the MIPI Alliance Display Working Group, co-defined requirements for a high quality compression specification that meets the needs of today's varied display usage, which includes a wide range of image types from still graphics and text overlaps, to photography and video. The new coding system also addresses usage on a wide variety of display types, sizes and viewing conditions.
Unlike more complex compression algorithms, such as MPEG, the DSC standard uses a less complex algorithm that provides a lower compression rate, and consumes fewer system resources including power. DSC provides low latency, which is important for interactive systems. Through extensive subjective testing of the standard, DSC is shown to deliver visibly lossless performance for graphics, text, images and video. The DSC encoding algorithm is based on delta pulse code modulation (DPCM), an Indexed Color History (ICH), an entropy encoder and a rate buffer that guarantees video data throughput for any possible display content.
The DSC standard is available for free to VESA members and for $350 for non-members. For additional technical information on DSC, please see VESA Display Stream Compression white paper.
VESA eDP v1.4 and MIPI DSI v1.2 are available to the members of the respective organizations.