DSC (Display Stream Compression) is a function developed by Video Electronics Standards Association (VESA) and it supports VESA DSC version 1.2a with a maximum compression ratio of 4:5:1 at 12 BPC (Bits Per Color). DSC allows users to transmit a larger amount of data using the same bandwidth. Without DSC, the DP (DisplayPort) 1.2a specification supports output up to 8K@30Hz with 4:4:4 encoding at 8 bits. When DSC is enabled, the resolution and color depth can be raised to 8K@60Hz with 4:4:4 encoding at 12 bits.
DSC adopts a software compression method which enables users to conveniently set the DSC parameters and compress images through Chroma 2238’s VPG Master software. The images can be previewed in real time when using the software.
The software comes equipped with 37 industry-standard DSC images for immediate use. Users can also import external test images (Bitmap, Jpeg, Tiff, and Portable Pix Map) and store up to 100 images compressed in accordance with DSC parameters.
With the VPG Master software, users can set BPP (Bits Per Pixel) and BPC (Bits Per Color/Component) to 8 / 10 / 12 bits each, providing a variety of compression ratios for users to set up their own test applications.
Users can set the number of horizontal and vertical cuts (Picture Parameter Set) for the test image.
- Horizontal: 1 / 2 / 4 / 6 / 8/ 10 / 12 / 16 / 20 / 24
- Vertical: 1 / 2 / 4 / 8
'Slice' technology reduces distortion after compression during DSC encoding, with various combinations of cutting methods providing users with a range of testing conditions and applications.
VPG Master software supports 5 video output modes: RGB / YCbCr / simple_422 / native_422 / native_420.
With the Read DSC Capabilities function, users can manually set the module placement Slot and DP Port to be read. After pressing the Read button, the VPG Master software will automatically load the DSC parameters of the sink under test (shown in the dotted orange box below) to help users understand the DSC capabilities of the device.
Users can input their own text string (up to 31 characters) onto the displayed picture, customize its font, size, color, and position, and preview the content and position of the string in the customized test chart section. The edited image can be directly downloaded to Chroma 2238, and can then be used to assess whether DSC has been enabled as well as its compression parameters.