HDMI It is an English acronym that alludes to High Definition Multimedia Interface . This expression can translate into our language as High Definition Multimedia Interface .
It is a standard that allows High definition digital video transmission and uncompressed multichannel digital audio through a single cable . Companies like Sony , Panasonic , Philips , Hitachi and Toshiba boosted this technology as a replacement for scart connector , which required at least two cables.
Thanks to HDMI technology, it is possible to connect a device such as a video game console, a player Blu-ray or one computer (a computer) to a TV . The HDMI, in short, transmits video and audio between two devices using a single cable. This not only means greater comfort compared to older connectors that required more than one cable, but another advantage of HDMI is that its most common connector is relatively small compared to its predecessors.
The connector Standard HDMI , known as type A , has 19 pins. He HDMI type C and the HDMI type D too They have 19 pins, although they are smaller and are oriented to the connection of portable devices (smartphones, tablets, etc.). There is also the HDMI type B , of 29 pins, whose use is not yet massive, designed for the screens of the future That will have higher resolution.
Since its creation, HDMI technology has been evolving to increase its capabilities. That is why it is possible to recognize several versions HDMI, from the HDMI 1.0 (which supports a maximum speed of 4.9 Gbps) up to HDMI 2.1 (48 Gbps), going through the HDMI 1.2 , he HDMI 1.3 , he HDMI 1.4 and the HDMI 2.0 .
It is important to mention that, although the HDMI standard does not establish a maximum length for cables, from a certain length the signal Start to dim.
While HDMI is the most used technology to transmit high resolution audio and video to all types of screens , there is also Displayport, a less popular alternative but that presents certain advantages. Since its launch, DisplayPort offered users the ability to transmit a signal from ultra high definition (UHD), that is to say 4k, at 60Hz, something that with HDMI was only possible with its version 2.0 and until then it required the use of two HDMI 1.4 cables connected simultaneously to the screen.
Since DisplayPort is less known than HDMI, it is common to find wrong information on the Internet when searching, either to solve problems or to buy a cable. However, choosing one of these two technologies does not always depend on the preferences of each user, but in general this is limited to the options present in their dispositives . For example, if our laptop only has a mini DisplayPort output and our TV or external monitor, an HDMI, we must get an adapter.
Regarding the HDMI channel protocols, we can mention the following:
* TMDS : transmits video, audio and data called "auxiliary". It can have a single or double link signaling method, as can be seen in HDMI type A or B, respectively. The frequency of pixels for video information ranges from 25 MHz to 330 MHz, and each can have a depth of up to 24 bits, regardless of the frequency. The maximum of audio channels is eight;
* CEC : is based on the protocol AV Link. It is used for remote operations and has a two-way bus. Its definition took place with the HDMI 1.0 specification and is also known as Anynet, Aquos Link, BRAVIA Link, Regza Link, VIERA Link and Easylink;
* HDCP : It's about a protocol to protect the contents of pirated copies, and affects that certain audio and video files cannot be transmitted between certain devices through an HDMI cable.