HDMI stands for High Definition Multimedia Interface
HDMI works as an interface between any multimedia devices to transfer audio and video signals. It is mainly a port in which cables(known as HDMI cables) are connected to transfer audio and video together. In old TV, monitors HDMI is not supported, they have the support of RCA cables only. Nowadays Tv, monitors such as HD, 4k, Blu-ray, etc even laptops have built-in HDMI support with HDMI port attached with them. HDMI is used as a trademark and brand name for a digital multimedia interface. Also, cable set-top boxes and video game consoles have HDMI.
HDMI cables have less signal noise than analog cables like RCA. HDMI can transmit high-definition video and audio signals over up to 8-channels. HDMI has EIA/CEA-861 standards for video formats, these standards electrically compatible with the DVI(Digital Visual Interface) interface. So HDMI doesn’t need digital-to-analog and analog-to-digital or any other signal conversion, for this reason, there is no data or signal loss happens, or no signal frequency is distorted so that the quality of video and audio is very much good in HDMI than other RCA, VGA cables.
History
The motivation of developing HDMI is to make a connector which is directly compatible with DVI(Digital Visual Interface). HDMI standard was developed by multiple companies, such as Hitachi, Silicon Image, Thomson, Philips, Sony, Panasonic and Toshiba, the development of HDMI started on 16th of April, 2002, in this time the version of HDMI was 1.0. Then in the year of 2003 on 23rd June first HDMI is tested at ATC(Authorized Testing Center) of Silicon Image.
After this all other companies are started to open their own ATC as fast as possible. See below:
| SL no. | Year | Company name | Country |
|---|---|---|---|
| 1 | 2004 | Panasonic | Japan |
| 2 | 2005 | Philips | Europe |
| 3 | 2005 | Silicon Image | China |
| 4 | 2008 | Philips | India |
After this the HDMI devices are sold in a very large quantity over the world i.e., from 2004 to 2009, the sold quantity of HDMI was 788 million, in which only 394 million piece was sold in 2009.
Then in October of 2011 the HDMI forum was established by the HDMI founders to make a platform for helping the companies which want to adopt HDMI technology in their devices. Then a huge amount of request was placed.
In 2013 HDMI authority has declared that there is more that 1300 HDMI adopters and nearly equal to 5 billion devices have been sold in which HDMI technology is used.
Characteristics
| Size | |||
|---|---|---|---|
| Types | Height | Width | No of pins |
| Type-A | 4.5mm | 13.9mm | 19 |
| Type-B | 4.45mm | 21.2mm | 29 |
| Type-C | 2.42mm | 10.42mm | 19 |
| Type-D | 2.8mm | 6.4mm | 19 |
| Audio & Video Signals | |
|---|---|
| Supported Audio | Supported Video |
| Dolby Digital, CD-DVD quality sound, Dolby Digital Plus, Dolby Atmos, Dolby TrueHD, DTS-HD Audio etc | All the video signal are supported in the maximum resolution |
| Performance | |
|---|---|
| Frequency | 25 Mhz to 340 Mhz |
| Bitrate | Up to 48 GB/sec |
| Color Depth | 24 bit to 48 Bit |
| Color Space | ITU-R BT709-5, xvYCC |
| Protocol | TMDS |
| Voltage | +5V |
| Ampere | 1.0 A to 1.5 A |
Also, the ordinary HDMI cables are capable of transmitting data at 10.4 – 11.0 GB/sec speed but the ports are capable of supporting up to 48 GB/sec data rate.
Versions of HDMI
HDMI has some versions from the 1st development to till now,
| HDMI Version | supported MAX resolution with refresh rate | Description |
|---|---|---|
| 1.0 | 1920×1080 at 60p | v1.0 supports first high-end digital TV standard |
| 1.1 | 1920×1200 at 60p | Same as 1.0 with extra Support of DVD audio |
| 1.2 | 1920×1200 at 60p | same as 1.1 with extra support of one Bit Audio format, such as Super Audio CD’s DSD, also need low-voltage |
| 1.3 | 2560×1440 at 60p | It boosted the resolution and colors by support xvYCC and it supports True HD and DTS sound |
| 1.4 or 1.4a | 3840×2160 at 30p | it has included home theater enhancements, 4K resolution, 3D, Blu-ray and also it supports 48bit color depth with 10.2 GB/sec data rate. |
| 2.0 | 3840×2160 at 60p | It has increased 4K frame rate and supports 32 audio channels. It can transfer data at speed of 18 GB/sec with 48 bit color depth |
| 2.0a | 3840×2160 at 60p | Same as 2.0, only extra, added the support of HDR(high dynamic range) in 2.0 version. |
| 2.1 | 7680×4320 at 60p to 3840×2160 at 120p | It can transfer data at a speed of 48 GB/sec with color depth 48 bit and it has the support of 4K at 120p, 8K, also dynamic HDR |
Advantages
- HDMI support high resolution at high refresh rate.
- HDMI supports audio and video together with one port and one cable.
- Also HDMI supports HDCP and 3D transmission.
- HDMI has comes with nowadays TVs, monitor, laptops, in many devices.
- HDMI has Simple connection to connect devices.
- It has integrated audio. video and content protection.
- HDMI uses digital interface instead of an analog interface.
- In HDMI high definition signal is not compressed at all.
Disadvantages
- While using HDMI sometimes authentication delay can be happen which causes blanks screen, which is irritating thing.
- HDMI cables as well as HDMI supported devices are costlier than others.
- There are limitations to field terminations of HDMI cables
- CEC(Consumer Electronics Control) causes confusion when the devices themselves change their configuration as they might get undetected by the control systems.
- HDMI use DVI interfacing so its need a HDMI-DVI adapter to connect the audio, otherwise the audio cannot be connected.
- Multiple applications are difficult to run simultaneously via HDMI.