High Definition Multimedia Interface (HDMI)

High Definition Multimedia Interface ( HDMI ) is a digital video / audio interface technology, is suitable for image transmission of dedicated digital interface, which can simultaneously transmit the audio and video signals, the maximum data transmission rate of 5Gbps. At the same time without the signals to be transmitted before the D / A or a / D conversion. HDMI with high bandwidth digital content protection ( HDCP ), to prevent having the copyright video content from unauthorized copying. HDMI has the extra space and can be used in future upgrade audio and video formats. But because of a 1080p video and a 8 channel audio signal needs less than 4Gbps, so HDMI has a large margin. This allows it to use a cable are respectively connected with DVD player, PRR receiver and.

In 2002 April, Hitachi, Panasonic, Philips, Silicon Image, Sony, Toshiba, Tomson and other 7 companies jointly set up the HDMI multimedia interface interface organization HDMI Founders ( HDMI Forum ), began to formulate a new era with HD standard digital video / audio interface technology. After more than half a year of preparations, HDMI founders officially released in December 9, 2002 1 edition of the HDMI standard, indicating HDMI technology formally entered the stage of history.

HDMI technology is not introduced, these manufacturers on a whim of impulsive behavior, on the contrary, in HDMI technology introduced behind, and the more deep-seated reason.

In 1999 April, in order to meet the digital era of high quality graphics imaging requirements, DDWG ( Digital Display Working Group ) digital display working group in the United States of America Silicon Image 's patented technology modelled, launched a project called DVI ( Digital Visual Interface ) interface, aims to unify a new era of digital display interface standard. This technique and by the IT industry, DELL, HP to Intel, IBM, Microsoft and other large enterprises a wide range of support. After more than 3 years of promotion, DVI technology in the computer display output fields has been applied quickly, but with the development of digital high-definition audio and video technology, the DVI interface also gradually exposed various problems, and even to some extent become the bottleneck of digital imaging technology.

DVI interface are the main problems:

* DVI interface to consider the object is a PC, for flat panel TV compatible ability in general. * DVI interface for image copyright protection for lack of support.

* DVI interface support only in the field of computer RGB digital signal, the digital color difference signals cannot support.

* DVI interface only supports 8bit RGB signal transmission, can't let wide color gamut display terminal displays the best performance.

* DVI interface for compatibility, reserved many pins to support the simulation equipment, interface resulting in greater volume, efficiency is very low.

* DVI interface can transmit image signals, for digital audio signal support without any consideration.

As a result of the above defects, DVI interface has been unable to meet the development of the whole industry needs. Therefore, whether it is IT manufacturers, flat-panel TV manufacturers, or Hollywood of the many publishers, urgently need a better to meet future HD video industry development interface technology, it is also based on these reasons, prompted the HDMI standard was born.