Why Display Stream Compression (DSC) is Important to Video Compression?

As technology advances, the demand for higher resolution and refresh rate displays has grown exponentially. Whether it's for immersive gaming experiences, professional content creation, or simply enjoying high-definition media, the need for efficient video transmission is critical. Enter Display Stream Compression (DSC) – a technology that addresses these demands by enabling efficient video compression without compromising quality.

Understanding Display Stream Compression (DSC)

What is DSC? Display Stream Compression (DSC) is a visually lossless compression algorithm standardized by the Video Electronics Standards Association (VESA). Its primary purpose is to reduce the amount of bandwidth required to transmit video data over various interfaces, such as HDMI, DisplayPort, and so on. By compressing the video stream, DSC allows for higher resolution and refresh rate displays without exceeding the bandwidth limitations of current video interfaces.

The Need for Efficient Video Compression

Increasing Resolutions and Refresh Rates Modern displays are pushing the boundaries with resolutions like 4K (3840 x 2160 pixels) and 8K (7680 x 4320 pixels), and refresh rates reaching 120Hz and beyond. While these advancements offer stunning visual experiences, they also require significantly more data to be transmitted. For example, an uncompressed 8K video at 60Hz with 10-bit color depth requires approximately 48 Gbps of bandwidth. This surge in data can overwhelm existing video interfaces, leading to a need for effective compression technologies.

Bandwidth Limitations Traditional video interfaces have limited bandwidth. For instance, HDMI 2.1 supports up to 48 Gbps, and DisplayPort 1.4 supports up to 32.4 Gbps. Without compression, transmitting uncompressed 4K or 8K video at high refresh rates would require more bandwidth than most interfaces can handle. This is where DSC comes into play, allowing for the transmission of high-quality video within the existing bandwidth constraints.

How DSC Works

Basic Principles DSC operates on the principle of visually lossless compression, meaning that the compressed video stream maintains a quality indistinguishable from the original uncompressed video to the human eye. It achieves this by compressing the video data in a way that minimizes loss of visual information.

Compression Process The DSC compression process involves several key steps. First, the video is divided into slices, typically 1/3 or 1/4 of the video width, and each slice is processed independently. Each slice is divided into smaller blocks (usually 3x3 or 6x6 pixel blocks). These blocks undergo quantization, where less important visual details are reduced to save space. Finally, entropy coding is applied to further compress the data by removing redundancy. DSC can achieve compression ratios of up to 3:1 while maintaining visual quality, effectively reducing the required bandwidth by two-thirds.

Benefits of DSC

Bandwidth Efficiency One of the primary benefits of DSC is its ability to reduce the bandwidth needed for transmitting high-resolution, high-refresh-rate video. For example, using DSC, an 8K video at 60Hz with 10-bit color depth can be compressed to require only about 16 Gbps of bandwidth, making it feasible to transmit over HDMI 2.1 or DisplayPort 1.4 interfaces.

Quality Retention Despite the compression, DSC is designed to be visually lossless, ensuring that the video quality remains virtually indistinguishable from the original. This makes it ideal for applications where image quality is paramount, such as professional content creation and high-end gaming.

Compatibility and Standardization DSC has been widely adopted and standardized by VESA, making it compatible with various display technologies and interfaces. This widespread adoption ensures that devices and displays from different manufacturers can work together seamlessly.

KVM Switches Supporting DSC

Display Stream Compression (DSC) isn't limited to computers alone; it's also a crucial factor in peripherals like KVM switches. Opting for a KVM switch that supports high resolutions and DSC ensures optimal performance across all connected devices, maximizing productivity and minimizing compatibility issues.

TESmart's range of 8K KVM switches integrates DSC technology and advanced EDID emulation for seamless video output. Compatible with a variety of devices, including PCs and consoles, these switches guarantee stable connectivity and high-quality visuals, making them ideal for modern work and gaming environments alike. More are supported here:

• 8K(4320p)@60Hz
• 4K(2160p)@60Hz
• 4K(2160p)@120Hz
• 4K(2160p)@144Hz
• 4K(2160p)@165Hz

Conclusion

In conclusion, Display Stream Compression (DSC) is essential for maximizing the capabilities of KVM switches, enabling efficient video compression without compromising quality. By supporting high resolutions and ensuring seamless operation across multiple devices like PCs, laptops, and game consoles, DSC-equipped KVM switches streamline workflow and enhance user experience. Whether for professional use demanding clear visuals or gaming environments requiring smooth, tear-free graphics, choosing a KVM switch with DSC ensures optimal performance and compatibility.