HDMI-High Definition Multimedia Interface, is the most ubiquitous interface connection and is found on almost all newer TVs, monitors, laptops, HDTV and other consumer electronic products. Although HDMI 2.1 was recently announced, HDMI 2.0 has become the modern standard video interface mostly widely used for 3820 x 2160 or 4K content.
HDMI 2.0 can provide 18Gbps of bandwidth, support 4K resolutions and 60Hz. While most film and television content is filmed at 24 fps, the FPS increase will potentially be more important for home videos, video games, and future content that has yet to be released.
These are all functionally the same cable, with the same pins and wires. The only difference is the connector has been made smaller to accommodate smaller devices.
|HDMI Version||Max Resolution||Max 4K Frame rate||HDCP 2.2||HDR||WCG||Hybrid Log Gamma||Dynamic Metadata|
With the TV industry moving inexorably toward Ultra HD “4K,” it was clear there needed to be more bandwidth in the connection to handle the future’s higher resolutions and frame rates. On that front, HDMI 2.0 delivers, supporting “4K” up to 60fps. This allows for full-resolution 4K 3D, along with higher-frame-rate 2D content, like (potentially) home videos and computer games (PC, not PS4/Xbox One). Since almost all movies are shot at 24fps, this increase is less important for feature films or scripted TV shows.
Check out What is refresh rate? for more on refresh and frame rates.
|HDMI 1.4||HDMI 2.0|
|4K @ 30Hz||Yes||Yes|
|4K @ 60Hz||No||Yes|
|Up to 32 Audio Channels||No||Yes|
HDMI 2.0 was announced as a standard in late 2013. It got a lot of people confused, wondering if they suddenly needed to throw away their TVs in order to get on this latest tech trend.
As far as tech advancements go, HDMI 2.0 is a pretty friendly one. It’s as much a standard of software as hardware, and cables designed for HDMI 1.4 systems will work just fine with new HDMI 2.0 devices.
What you need to make sure is that both ends of your entertainment chain – your TV and Blu-ray player, for example – support the standard. It’ll mean they’re geared up for the new standards we’ll dig into shortly. Some previously HDMI 1.4 hardware needs nothing more than a firmware update HDMI 2.0 is a reimagining of the interchange between your bits of home entertainment gear, one that factors in the immense amount of data required to get high-quality audio and video to something like a 4K 3D-capable TV.
HDMI 1.4 introduced the kind of bandwidth required to deliver 4K video, but HDMI 2.0 can dole out 4K video without compromise, at 50 and 60 frames per second. In HDMI 1.4, the rate of 4K was limited to 24 frames per second.
24p and 30p are perfect for watching films, but there are times when the extra speed of 50p and 60p come in handy. Gaming could make great use of 60p content, while more films are being shot at higher frame rates, giving quite a different look from that of slow old traditional cinema.
Just as important as the higher frame rates for Ultra HD/4K HDMI 2.0 enables, the extra bandwidth also means HDMI is able to transport 4K video at 10-bit and 12-bit color depths. With HDMI 1.4 it was limited to 8-bit.
What’s the difference between 8-bit, 10-bit and 12-bit color? It tells you how much information goes into each pixel’s color. 8-bit color results in a color palette of 16.7-million colors – it’s a figure you may have heard floating about if you’ve ever read into buying a screen of some kind.
As 12-bit color ramps-up the specificity of the color information that goes into rendering an image, the total number of possible colors is 68.7 billion. That exponential ramping-up of data is what makes transporting 4K 12-bit such a data-heavy task.
These higher color bit rates are often labeled “deep color”, so if you see that term you now know what it refers to.
It’s this ability that unlocks High Dynamic Range, which gives you video information required to more and brighter colors.
Here’s a neat one: HDMI 2.0 supports the delivery of two different video streams, which can be delivered to the same screen. Exactly what will happen to those streams will depend on what the box (perhaps a TV) at the end does with them.
This improvement is really a pure bandwidth issue. 18Gbps gives a comfortable pipe for two high bit-rate 1080p streams with audio.
It sounds like a gimmick, but this adds a hardware standard for something we’ve seen in proprietary form before now. With a 3D TV, it opens up ‘dual view’ TV watching, where you’d use a pair of 3D glasses to deliver two completely difference streams to two people watching the same TV.
HDMI 2.0 makes huge updates to the often-neglected side of AV – audio. From being able to transmit just eight channels, you can now send 32.
This is what has enabled the Dolby Atmos standard to be moved over to home cinema receivers. It was once the preserve of just a few super high-end cinema sound systems, but you can now get it in your home.
Dolby Atmos is all about giving your much more accurate positional audio, making sound appear 3D for a more immersive cinema experience.
The quality of the audio streams has been improved too. Sample rates now go up to 1536KHz. In a full 32-channel system that means you’d get 48KHz per channel. That’s decent if not the sort of sample rate that get audio nerds drooling. 24-bit, 192KHz is where it’s at for that crowd. Of course, those sort of frequencies are perfectly possible with HDMI 2.0, just not if you want 32 channels of audio
The HDMI1.4 release begins with the addition of the HDMI Ethernet and Audio Return Channel (HEAC) function, which is to add Ethernet signals and sound echo signals in the pins of HDMI (pin14 and pin19).The Ethernet signal is the network sharing of HDMI output devices (such as computers, DVDS, etc.) and receiving devices (such as TV).
|Signal Standard||Max Resolution and Frame Rate||Signal Type||Notes|
|DVI-D||2560 x 1600 @ 60fps||RGB @ 10-bit color (single)||Uncompressed video,Max cable length 10m,3,96Gbps,Disbanded|
|HDMI||4096 x 2160 @ 24fps(30fps for Ultra HD) 1920 X 1080 @ 120 fps||RGB,Y’CbCr @ 16-bit color||HDCP,15m cable length,8.16Gbps|
|Displayport||3840 x 2160 @ 60 fps|
2560 x1600 @ 120 Hz
|RGB,Y’CbCr @ 16-bit color||HDCP and AES,33m cable length,17.28Gbps,2m at full resolution|
HDMI cable and DVI cable as two input-output media interfaces in home network are posing difficulty in distinguishing them. In fact, the biggest difference between these two transmission media lies in their layout. An HDMI cable is more compact and resembles a USB cable, while a DVI cable is usually bigger in size. Another major difference is in capability: the HDMI supports audio and video, whereas the DVI is strictly video-only.