High Definition Multimedia Interface is a Branded audio and video interface for uncompressed data transmission and compressed or uncompressed digital audio data from a HDMI compliant source device, like a display controller to a computer monitor, compatible video projector, digital audio device or digital television. HDMI is a digital replacement for analog video standards. A single HDMI cable can transmit both audio and video signals, so only a single cable is needed to complete the entire setup for data transmission. A few devices have their own HDMI cable, but sometime more than one are also needed.
A number of versions of HDMI have been industrialized and set out since initial release of the technology but altogether use the same cable and connector for HDMI. HDMI cable has three separate physical communication channels, which include TMDS (Transmission Minimized Differential Signaling, on HDMI interleaves audio, video and auxiliary data using three different packet types which are known as Video Data Period, Control Period and Data Island Period), DDC (Display Data Channel, a communication Channel based on bus specification, used by the HDMI source device to read data from the HDMI sink device to pick up what type of audio/video formats it can take.) and the optional CEC (Consumer Electronics Control, is HDMI feature designed to permit the user to command and control equal to 15 CEC enabled devices, which are attached through HDMI).
HDMI Cable is made up of four shielded twisted pairs with seven separate conductors shown in the figure. Following are the cables which are defined for HDMI universally:
- Standard HDMI Cable- up to 720p and 1080i
- Standard HDMI Cable with Ethernet
- Standard Automotive HDMI Cable
- High Speed HDMI Cable
- High Speed HDMI Cable with Ethernet