Serial Digital Interface (SDI) is a family of digital video interfaces standardized by SMPTE for professional broadcast and video production equipment. SDI transmits uncompressed digital video over 75-ohm coaxial cable using BNC connectors.
Common SDI standards include:
- SD-SDI (SMPTE 259M) – 270 Mb/s for standard definition video
- HD-SDI (SMPTE 292M) – 1.485 Gb/s for high definition video (720p, 1080i)
- 3G-SDI (SMPTE 424M) – 2.97 Gb/s for 1080p video
- 12G-SDI (SMPTE 2082) – 12 Gb/s for 4K video
SDI can carry embedded digital audio channels alongside video.
