In addition to the regular serial digital interface described here, there are several other similar interfaces which are similar to, or are contained within, a serial digital interface.
There is an expanded specification called SDTI (Serial Data Transport Interface), which allows compressed (i.e. DV, MPEG and others) video streams to be transported over an SDI line. This allows for multiple video streams in one cable or faster-than-realtime (2x, 4x,...) video transmission. A related standard, known as HD-SDTI, provides similar capability over an SMPTE 292M interface.
The SDTI interface is specified by SMPTE 305M. The HD-SDTI interface is specified by SMPTE 348M.
The standard SMPTE 349M: Transport of Alternate Source Image Formats through SMPTE 292M, specifies a means to encapsulate non-standard and lower-bitrate video formats within an HD-SDI interface. This standard allows, for example, several independent standard definition video signals to be multiplexed onto an HD-SDI interface, and transmitted down one wire. This standard doesn't merely adjust EAV and SAV timing to meet the requirements of the lower-bitrate formats; instead, it provides a means by which an entire SDI format (including synchronization words, ancillary data, and video payload) can be encapsulated and transmitted as ordinary data payload within a 292M stream.
The HDMI interface is a compact audio/video interface for transferring uncompressed video data and compressed/uncompressed digitalaudio data from an HDMI-compliant device to a compatible computer monitor, video projector, digital television, or digital audio device. It is mainly used in the consumer area, but increasingly used in professional devices including uncompressed video, often called Clean HDMI.
The G.703 standard is another high-speed digital interface, originally designed for telephony.
The HDcctv standard embodies the adaptation of SDI for video surveillance applications.
The CoaXPress standard is another high-speed digital interface, originally design for industrial camera interfaces. The data rates for CoaXPress go up to 6.25 Gbit/s over a single coaxial cable. A 20 Mbit/s uplink channel and power over coax are also included in the standard.