The HDMI terminal can transmit uncompressed audio signals and video signals, and provide compatible equipment including set-top boxes, DVD players, personal computers, integrated amplifiers, digital audio and TV sets, etc., and have common data Connecting pipes can transmit audio and video signals at the same time. Since the audio and video signals use the same cable, the installation of the system is greatly simplified. HDMI is designed to replace the older analog video transmission interface such as SCART or RCA terminals.
HDMI supports any TV and computer image format, including standard and high-definition video images, and multi-channel digital audio. During transmission, various video data will be encoded into data packets by the HDMI transceiver chip using Transition Minimized Differential Signaling (TMDS) technology.
When the HDMI terminal specification was released, the maximum pixel transfer rate was 165Mpx/sec, which was sufficient to support 1080p resolution at 60 frames per second, or UXGA resolution (1600x1200). Later, it was extended to 340Mpx/sec in the HDMI 1.3 specification to cope with future possibilities. demand.
HDMI can also support uncompressed 8-channel digital audio transmission (sampling rate 192kHz, data length 24bits/sample), and any compressed audio stream such as Dolby Digital or DTS. It also supports 8-channel 1-bit audio used by SACD. In the HDMI 1.3 specification, support for uncompressed audio streaming with ultra-high data volume such as Dolby TrueHD and DTS-HD has been added.
The standard Type A HDMI connector has 19 pins, and another Type B connector that supports higher resolution has been defined, but it is still not used by any manufacturer. The Type B connector has 29 pins, allowing it to transmit expanded video channels to meet future high bandwidth requirements, such as WQSXGA (3200x2048px).
Type A HDMI is backward compatible with the single link DVI-D or DVI-I interface (but does not support DVI-A) currently used by mainstream computer screens and display cards, which means that the signal source using the DVI-D interface can pass The conversion cable drives HDMI display devices, but this conversion solution does not support audio transmission and remote control functions. In addition, DVI monitors without HDCP certification will not be able to watch the video data output from HDMI with HDCP encryption protection.
