HD-CVI Technology for CCTV Systems

HD-CVI, also written HDCVI, is High Definition Composite Video Interface: a video transmission technology developed by Dahua for compatible coaxial CCTV systems. It can support an upgrade path where suitable coaxial cabling already exists.

How the system connects

A compatible camera sends its video signal to a supported DVR or XVR. The recorder handles recording and the available network-viewing functions. Audio, camera control, and Power over Coax may be supported, but each feature depends on the specific camera, recorder, and accessories.

HD-CVI versus IP cameras

HD-CVI and IP describe different system connections, not a universal ranking of image quality. Both include equipment with different resolutions, lenses, low-light performance, analytics, and recording capabilities. Choose from the actual models and the site requirements.

IP cameras send network video streams. HD-CVI cameras use a supported coaxial video path to the recorder. A network-connected DVR still needs secure accounts, updates, and controlled remote access; coaxial camera wiring does not make the whole system immune to cybersecurity risks.

Check more than the maximum megapixels

Verify the camera’s selected output format, resolution, and frame rate against the recorder’s input specifications. Then check recording resolution and frame rate separately. A recorder’s maximum input resolution is not a promise of the same recording performance on every channel.

Existing cable is an asset only if it is suitable

Inspect cable construction, length, connectors, and intermediate devices. Use manufacturer-supported transmission limits for the actual format and equipment. Do not split or extend a signal using unapproved accessories, and do not assume ordinary coax automatically supplies power.

Upgrade checklist

  • Inventory existing cameras, recorder, cable routes, and power supplies.
  • Define the detail and coverage needed at each camera.
  • Confirm format, resolution, frame rate, and optional-feature compatibility.
  • Check recording capacity, storage, and remote-access requirements.
  • Test representative cable runs and recorded playback before a full rollout.

Continue with HD-CVI compatibility, EX-SDI and HD-SDI, Power over Coax, and the CCTV FAQ.