VESA introduced the first Display Stream Compression (DSC) standard in 2014 and it quickly became the industry standard for data compression across the display interface. DSC was the first to offer a low latency, low complexity codec expressly designed for this purpose. DSC 1.1 has been incorporated into the VESA Embedded DisplayPort (eDP) and MIPI® DSI embedded mobile interface standards, and DSC 1.2a into the DisplayPort and HDMI® external video interface standards. The latest VESA Display Compression-M (VDC-M) standard has also been adopted into the MIPI DSI standard.
For mobile applications, DSC 1.1 and VDC-M mainly serve to reduce the video interface data rate, which reduces system power, prolongs battery life, and reduces interconnects to enable sleeker designs. For external display interfaces, DSC 1.2a extends resolution across existing connectors and cables, enabling 8K video and legacy support from the same connection.
The VESA Display Compression Codecs are designed to work with a wide variety of displays in a wide variety of use cases. They provide efficient compression and visually lossless quality for consumer and professional products. They work seamlessly with today’s wide variety of visual content including text and graphics, photographs and video, including high resolution and high dynamic range (HDR) content, and the dramatic and/or pastille graphics in games. The codecs are designed to perform well in HDR and Wide Color Gamut consumer and professional displays, in embedded displays for mobile computing, tablet, and high-resolution smart phones, in automotive applications, and in artificial and virtual reality headsets.
To assure visually lossless performance, VESA’s display interface compression standards are rigorously tested for subjective image quality using a diverse group of test subjects. Test images and a summary of test results are available from VESA.
|Features||DSC 1.1||DSC 1.2a||VDC-M 1.1||VDC-M 1.2|
|Visually lossless compression performance verified by subjective testing|
|30 bit color, compression ratio (bits/pixel)||3.75:1 (8 bpp)||3.75:1 (8 bpp)||5:1 (6 bpp)||5:1 (6 bpp)|
|24 bit color, compression ratio (bits/pixel)||3:1 (8 bpp)||3:1 (8 bpp)||4:1 (6 bpp)||4:1 (6 bpp)|
|Backwards compatibility||DSC 1.x||DSC 1.x||VDC-M 1.x||VDC-M 1.x|
|Both encoder and decoder are specified||✓||✓||✓||✓|
|Normative C language code||✓||✓||✓||✓|
|8, 10, 12 bits per color support||8/10/12||8/10/12/14/16||8/10/12||8/10/12|
|High Dynamic Range-ready||✓||✓||✓||✓|
|RGB and YCbCr 4:4:4 native encoding||✓||✓||✓||✓|
|YCbCr 4:2:0 or 4:2:2 native encoding||No||✓||✓||✓|
|Image test data base available from VESA||✓||✓||✓||✓|
|Compliance test guideline and test scripts||✓||✓||In Development|
|Publicly known adopting standards||MIPI DSI 1.2
VESA eDP 1.4b
VESA DP 2.0
VESA eDP 1.4b
|MIPI DSI-2 1.1||MIPI (forthcoming)|
|✓ = Available now|
1 These codecs are capable of operating in real-time within the throughput rate guidance, refer to the technical specification for details.