🎥

Video Display Interfaces Overview

Jun 6, 2025

Overview

This lecture covers common video display interfaces, their features, compatibility, and physical characteristics, including HDMI, DisplayPort, DVI, VGA, and USB-C.

HDMI (High-Definition Multimedia Interface)

  • HDMI transmits both digital audio and video through a single 19-pin cable.
  • Maximum effective cable length for HDMI is about 20 meters before signal loss occurs.
  • HDMI Type-A is the most common connector for TVs and monitors.
  • Only HDMI cables fit the unique indented rectangular HDMI port.

DisplayPort

  • DisplayPort sends digital audio and video using packetized data, similar to Ethernet.
  • It is compatible with HDMI and DVI via passive adapters.
  • Full-size and mini DisplayPort connectors exist; full-size often found on desktops.
  • DisplayPort connectors lock in place and have a release button to prevent accidental unplugging.
  • DisplayPort and HDMI connectors differ in physical shape and cannot be interchanged.

DVI (Digital Visual Interface)

  • DVI only transmits video signals; no audio support.
  • Multiple DVI types: DVI-A (analog), DVI-D (digital, single or dual link), and DVI-I (integrated analog and digital).
  • Single link DVI: 3.7 Gbps, supports up to 1920x1200 resolution; dual link provides double the bandwidth.
  • DVI can be compatible with VGA for analog signals.
  • Check DVI cable and port types to ensure compatibility.

VGA (Video Graphics Array)

  • VGA is an older, analog-only standard using a 15-pin (DB15/DE15) D-shaped connector.
  • Signal quality degrades after 5-10 meters of cable length.
  • VGA connectors are usually blue according to standard PC system design guides.
  • Only video signals are sent through VGA, not audio.

USB-C and Other Video Transmissions

  • USB-C is a connector type capable of carrying multiple signals: power, serial data, HDMI, DisplayPort, Thunderbolt, and MHL.
  • With the correct cables and connections, USB-C can support a variety of video outputs.

Key Terms & Definitions

  • HDMI (High-Definition Multimedia Interface) — Digital interface transmitting audio and video over a single cable.
  • DisplayPort — Digital interface using packetized data for audio and video, with locking mechanism.
  • DVI (Digital Visual Interface) — Video-only interface with analog, digital, or integrated capability.
  • VGA (Video Graphics Array) — Legacy analog video interface with a 15-pin D-shaped connector.
  • USB-C — Versatile connector capable of transmitting power, data, and multiple video signals.

Action Items / Next Steps

  • Identify the video connectors on your devices and verify cable compatibility before connecting.
  • Review the physical shapes of HDMI, DisplayPort, DVI, and VGA connectors for proper identification.