Hdmi | Vsif

Abstract The VESA DisplayID Structure for HDMI (VSIF HDMI) is a critical, yet often overlooked, extension mechanism defined in the HDMI 2.0 and later specifications. It enables the transmission of VESA-defined metadata, particularly DisplayID blocks, over an HDMI link. This paper details the motivation, packet structure, operational principles, and use cases of VSIF HDMI, distinguishing it from legacy EDID and CEA-861 Vendor Specific Data Blocks. Special focus is given to its role in supporting advanced display features like high refresh rates, adaptive sync, and multiple monitor topologies. 1. Introduction HDMI (High-Definition Multimedia Interface) has long relied on EDID (Extended Display Identification Data) and CEA-861 extensions to communicate display capabilities. However, as display technologies advanced—introducing variable refresh rates (VRR), Display Stream Compression (DSC), and high dynamic range (HDR) beyond the original HDMI 1.4b scope—the need for richer, more flexible metadata became apparent.

| Byte Offset | Field | Size (bits) | Description | |-------------|-------|-------------|-------------| | 0 | InfoFrame Type | 8 | 0x81 (VSIF) | | 1 | Version | 8 | 0x01 for HDMI VSIF v1 | | 2 | Length | 8 | Number of bytes following (max 31) | | 3 | IEEE OUI[0] | 8 | 0x00 | | 4 | IEEE OUI[1] | 8 | 0x11 | | 5 | IEEE OUI[2] | 8 | 0x11 (VESA) | | 6 | VSIF Payload | Variable | Contains DisplayID structure(s) | After the OUI, the payload begins with a DisplayID Header : vsif hdmi