What is HDMI?
HDMI (High-Definition Multimedia Interface) is a standard for connecting video and audio signals using a single cable from one electronic device. Using a single HDMI cable, a video, and audio signal can be sent from one device, such as a DVD player, to another device using HDMI like a television set. Since HDMI is an industry standard, consumers can purchase any device with HDMI and connect it to another device that uses the HDMI connection.
Created in 2002, the standard for HDMI developed by Hitachi, Panasonic, Phillips Electronics, Silicon Image, Sony, Technicolor, and Toshiba. The standard includes specifications for the connectors, cables, and electronic video and audio signals and it currently managed by HDMI Licensing, LLC. HDMI Licensing is an industry organization that licenses the HDMI technology to over 1600 manufacturers of electronic equipment who use HDMI. With over four billion HDMI devices shipped, HDMI is supported by major motion picture studios.
HDMI cables and connectors
The unique shape and size of the standard HDMI connector is how mos people recognized an HDMI connection. With the standardized size and shape, one end of an HDMI cable can only fit one way into an HDMI connector. There are several different sizes of HDMI connectors, however since the standard was adapted to make smaller connector sizes possible for smaller d vices. For example, some video cameras and smartphones use the mini-HDMI size connector and a cable which has a mini-HDMI connector on one end can have a standard size connector on the other. The smaller size makes it possible to connect a video camera directly to a television set or monitor with an HDMI connector even though they have different size connectors.
Cables for HDMI can be different lengths as well, and the standard allows for cable lengths as long as ten meters. A longer connection is even possible with an electronic repeater but is usually not necessary since most HDMI devices are located near each other, like a cable box and a television display.
There are currently five different types of HDMI cable types. One type is strictly for automotive use in automobile video systems and is designed specifically for automobile manufacturer-installed and after-market video systems. You usually won't even see the HDMI cables in a car since they are concealed and hidden from view.
Two other types of HDMI cables are for standard HDMI or High-Speed HDMI. Standard HDMI is the most commonly used HDMI cable for home audio and video. The High-Speed HDMI cable standard is for 3D video, Blue-ray disk players, and the newer 4K (for 4,000 lines of resolution) video. You won't need the High-Speed HDMI cable types unless you use one of these types of devices. Both the standard and the High-Speed HDMI cable types have another variation, and that's the ability to carry Ethernet, so each type is available as anEthernet capable version or non-Ethernet capable version. You only need the Ethernet version if your equipment specifies that requirement.
History
HDMI was introduced when High-Definition television was introduced and required higher-quality video signals than existing video connectors could provide. In 2002, the television industry was going through a transition from standard-definition television to high-definition television.
Television creates a visual image by displaying an image made up of lines that light up the screen in some way. High-Definition television uses more lines than standard definition so the image is clearer and sharper and can be larger in height and width and still seem clear to the human eye. Standard -definition displays 352 lines on any display, regardless of how large the display is. With a small display, the human eye can't make out the lines and the image appears relatively clear. High-Definition displays use either 720 lines (called 720P), or 1080 lines (called 1080P) which is over twice as many lines on the display as standard definition video.
As a result of the higher number of lines of high-definition video compared to standard-definition video, images on the same she screen appear sharper and clearer and screens can be ade larger without losing detail. In addition to the higher number of lines and sharper images, the High-Definition changed the ration of the image width to the height from 4:3 ration to a 16:9 ratio. The 16:0 ratio means every High-Definition display is wider than the older standard-definition display.
In addition to the screen being a different format, the higher number of lines for the image required more information to create each image on a screen. As a result, the industry started using a digital signal using digital data with zeros and ones. The electronics industry decided to make cabling easier for consumers and include both the video and audio signals on one cable.
HDMI Advantages
Before HDMI cables existed the video, and audio signals were sent from one device to another using separate cables, one for video, and one each for left and right stereo. Add surround sound and audio and video cables created a spaghetti-like mess to connect a home theater system together. Add to that separate components for the video and audio sources such as a CD player, DVD player, cable box, video game player and different cable types and connectors was getting in the way of consumers buying and easily attaching consumer electronic devices.
The invention of HDMI has replaced eleven separate types of cables previously used for audio and video connections. HDMI technology also provides a higher quality signal for higher resolution video, higher quality audio and now also includes the ability to carry an ethernet signal between devices. Using an HDMI switch, several separate devices can be connected to an HDMI hub, which can then be connected to an HDMI connector on a television set even if the television set has only one or two HDMI connectors, making it possible for you always to connect any additional home electronic HDMI compatible devices to your television set.
To my way of thinking
HDMI has simplified cabling for television and audio systems for the average consumer as well as made it easier to buy electronic devices from one manufacturer and use them with another, as long as both use the widely-used HDMI industry standard.