HDMI (High Definition Multimedia Interface) is an interface for

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HDMI (High Definition Multimedia Interface) is an interface for transmitting digital      The problem of possible data losses in longer cable lengths –usually after approxi-
audio and video data und video data which was mainly developed for connection to         mately 3-5 meters – was already a topic when HDMI 1.3b was introduced. There are
devices from the Home Video Area (televisions/recorders, set top boxes, camcorders       factors here which influence the signal quality which have mainly to do with the cable:
and SAT/cable receivers, for example). The HDMI is downwards compatible to               the performance of the HDMI interface in transmitting and receiving devices and also
established DVI (Digital Visual Interface). This means that an HDMI-DVI adapter          the transfer rate of the signal also play a role. The higher the latter is, the shorter the
cable can connect a DVD player with an HDMI output to a projector with a DVI input,      „non problematic“ cable length is. If a 4.95 Gbit/s signal could be transmitted with
for example.                                                                             a previous HDMI with a cable length of up to 10 meters, for example, this length
                                                                                         shortens now with the HDMI 1.3b to only 5 meters.
It is important for all HDMI and DVI connections that both connected components
(hardware/device/interface) are provided with HDCP copy protection. Transmission of      Important: All existing HDMI cables also transmit data in accordance with HDMI 1.3b.
encrypted, digital video data according to this standard is not possible without HDCP!   This is only guaranteed up to 4.95 Gbit/s however, in other words slightly less than
PLEASE NOTE ! DVI has existed in the computer area for some time – without HDCP          half of the maximum data rate of the HDMI 1.3b. The following therefore has to be
however. Many projectors and also a few plasma TV devices come from the computer         taken into consideration: HDMI 1.3 defines the maximum data rate but it does not
area and have therefore not implemented HDCP.                                            increase the data rate of a given signal. An existing 1080p signal transmitted with
                                                                                         HDMI 1.3b will continue to run with HDMI 1.3b - with the same quality and the same
HDMI has been continuously developed in recent years. This reflects in the states of      cable length. The quality of the cable will start to be decisive only when the connected
the corresponding versions: HDMI 1.0, HDMI 1.1, HDMI 1.2, HDMI 1.2a, HDMI 1.3            components replace the new technical improvements possible with HDMI 1.3b to
and now currently HDMI 1.3b. HDMI 1.3 doubles the band width of the data rate from       send correspondingly higher synchronized signals.
previously 4.5 Gbit/s (165 Mhz) to 10.2 Gbit/s (340 Mhz) compared to the previous
version 1.2. Another plug type has been established with the introduction of HDMI 1.3.

HDMI Typ A Plug (left), Mini HDMI Typ C Plug (right)

The greatest confusion is with 1080p (full HD). Since 1080p was also a topic in the
media with the introduction of HDMI 1.3 onto the market, several people have the
impression that HDMI 1.3 is required for 1080p. In fact both these terms have nothing
to do with each other. 1080p was already a part of the HDMI specifications already in
Version 1.0. Additional data rates were introduced with HDMI 1.3 which were above
those of 1080p.