The HDMI connector has quickly become the standard interface for connecting your audio-visual devices together.
However, many people are confused by this connection type, so here we look at some common issues and explain it in more detail.
What does the connector on the device look like?
The HDMI connection on the back of your TV or Blu-ray player looks like this.
It's a bit like a USB port on your computer - but a bit thinner and wider.
The connection is designed so that HDMI cables will only fit one way round.
What does the cable look like?
The HDMI cable that is used to connect two devices looks like this.
You just need one cable between devices to transfer the sound and the picture.
What does it do?
HDMI cables transmit digital video and digital audio signals between devices.
high-definition video signals and surround sound audio (5.1 Dolby Digital and high-definition audio soundtracks found on Blu-ray players).
When should I use it?
As a general rule, this is the best connection to use to link most modern audio visual devices together....assuming each device has an HDMI port of course!
Most devices made in the last couple of years will probably have these, older devices may not.
Remember, the HDMI connection sends the video and the audio signals, and so one cable is all that is required.
If you have a DVI connector on one device and HDMI on another, then it is possible to buy DVI to HDMI cables to send from one connection type to another. This will only send the picture as, unlike HDMI, DVI only supports video signals. The DVI device may also need to be HDCP-enabled in order to send certain signals. All HDMI devices support HDCP.
What else can you tell me?
HDMI allows the transmission of all video signal types (including high-definition signals up to full 1080p) - plus up to 8 channels of uncompressed digital audio (such as Dolby TrueHD and DTS-HD Master Audio).
There have been different versions of the HDMI specification over the last few years. The latest version currently in widespread use is HDMI v.1.3, although HDMI 1.4 has now been released. The older versions have some limitations as to the features they support, and therefore the HDMI inputs and outputs on older devices may not have the same functionality as newer devices.
HDMI cables are often described as version 1.3 or 1.4 etc. However, HDMI cables really only come in two versions - 'standard' speed and 'high' speed. As a rule of thumb, a category 1 'standard' speed cable will be fine for 720p and 1080i signals, whereas a category 2 'high' speed cable will be more suitable for higher data rates such as 1080p signals.
Before you buy an HDMI device, you should check that it has been certified to the most recent version to be sure it will support the latest features. Of course, if you don't need these features then it doesn't matter so much.
The main features of each version are:
HDMI 1.0: release version supported data transfers up to 4.9 Gb per second and the playback of standard Blu-ray disc video and audio at full resolution.
HDMI 1.1: support for
HDMI 1.2: support for
HDMI 1.3: supported bandwidth increased to 10.2 Gb per second. Added support for streaming high-definition Dolby TrueHD and DTS-HD Master Audio to external AV receivers for decoding. Additional (rarely used) functionality such as Deep Colour and auto lip-sync.
HDMI 1.4: support for 3D TV control codes, higher video resolutions and an HDMI ethernet connection between two devices.
For more detailed information go to the HDMI FAQ.