HDMI stands for high definition multimedia interface, which is a system of connection often used with digital video and audio. A HDMI cable is a special cable that is able to transmit uncompressed digital audio and video simultaneously.
This lead is used in connecting digital input sources to other digital electronic equipment such as computer monitors, televisions and receivers. A HDMI compliant TV, cable and source are required in order to view high definition video, eight channel digital audio and Blu-Ray. HDMI cable works with any TV or PC video format, including standard and high definition.
HDMI was first developed in 2002 to fill the need for a higher quality digital visual and audio system. Many different television, computer and electronic manufacturers have adopted the HDMI specifications. These standards were introduced by an association of electronic manufacturing companies, in cooperation with major music and movie distribution firms. HDMI uses the EIA / CEA-861 standards that define video waveforms and formats, auxiliary data, transport of compressed and uncompressed audio, and also LPCM audio.
Two different types of leads are available in the market, namely category one and two. These categories only apply to versions 1.3 and higher, which were made available in 2008. Category one cables bear the standard HDMI cable label and are suitable for transmitting 720p or 1080i video and audio signals. Leads in category two are also considered fast speed leads, and can carry video and audio signals of 720p and 1080i as well as 1600p. Category two HDMI cables are the only type guaranteed to work with a cable that is greater than 16 feet long.
When choosing a lead, it is important to consider the length.
Because of signal attenuation, there is a limit to how long a lead should be. Cables that are too long transmit very weak digital signal, resulting to blinking images on the screen. The problem of loss of signal as a result of excess cable length can be taken care of by using HDMI extenders, equalizers or repeaters. These are devices that can be used to connect the cables to each other, thereby extending the cable length without losing signal strength. The maximum length that can be used depends on the cable's category. Cables in category five and six can increase the overall cable length to as much as 164 feet. If an extender used is optical fiber based, the overall cable length can increase to 328 feet.