HDMI FAQ

On this page we have listed many of the common questions related to HDMI cables and connectors, and provided simple answers to each.

Furthermore, if you find there is an issue related to this subject that we haven't covered, then you can post your own question at the bottom of the page and we will try our best to find an answer.

What does HDMI stand for?

HDMI stands for High-Definition Multimedia Interface.

What are the different versions?

Version 1.0:

The release version of the HDMI standard. An audio and video interface which allowed the transfer of standard and high-definition video - and up to 8 channels of uncompressed digital audio.

Maximum data transfer of 4.9 Gb per second.

Version 1.1:

Support for DVD Audio.

Version 1.2 and 1.2a:

Support for the One Bit Audio format such as SACD (up to 8 channels).

Fully specified support for CEC.

Version 1.3:

Increased bandwidth to 10.2 Gb per second.

Improved colour - support for Deep Colour and x.v.Colour. These provide increased colour depths and the ability to reproduce any colour the eye can see.

Lip sync - allows devices to automatically synchronise the picture and sound.

Support for streaming high-definition Dolby TrueHD and DTS-HD Master Audio to an AV receiver for decoding.

Defined two standards for HDMI cables - category 1 and 2 (see below).

Version 1.4:

Support for increased resolutions - up to 3840 x 2160p at 25/30Hz and 4096 x 2160p at 24Hz.

Support for an audio return channel - allows the TV to send audio from an internal tuner to the AV receiver - therefore allowing an easy way to send this audio to a home theater sound system.

Support for an ethernet connection over HDMI - therefore allowing an internet or home network connection through the cables.

Support for 3D TV signals.

Do I need HDMI 1.3 to hear HD audio?

No. The versions of HDMI before 1.3 fully supported the transfer of HD audio. However, this required the HD audio to be decoded by the playback device and then sent across the cable to the amplifier as a Linear PCM signal (LCPM). The amplifier/receiver also needed to support HDMI audio (not all did).

What was added by HDMI 1.3 was the ability to to bitstream the HD audio to the amplifier/receiver. This means the HD audio signal is sent ('streamed') directly to the amplifier/receiver without being decoded first, and the decoding is done by the receiver instead.

For this to work, all of the parts of the chain must be HDMI 1.3 compliant.

What is a category 1 cable?

A 'standard' cable that has been tested at speeds of 75 MHz - or up to 2.25 Gb per second. This is roughly equivalent to a 720p or 1080i signal.

What is a category 2 cable?

A 'high speed' cable that has been tested at speeds of 340 MHz - or up to 10.2 Gb per second. This is roughly equivalent to a 1080p signal at the increased colour depths and resolutions.

Do I need an HDMI 1.3 cable?

Cables aren't defined by the version numbers 1.2, 1.3 etc. These numbers refer to the capabilities of the hardware connections in your devices. To transfer 1080p video and 3DTV signals you should make sure you buy a category 2 'high speed' cable to ensure it will transfer the high data rates required. If you aren't sending the highest resolution signals, then a standard category 1 cable should be sufficient.

What is the maximum cable length?

There is no defined maximum cable length for HDMI cables - only a required performance. The ability of a cable to accurately reproduce signals over a long distance is very much dependant on the build quality of the cable - and the quality of the circuits in the devices. However, in practice, a high quality cable should be able to transfer data successfully over about 10 metres before a repeater or amplifier is required to boost the signal.

Are the new versions compatible with the old versions?

Yes. HDMI is fully backwards compatible with older versions.

What is the difference between HDMI and DVI?

They are essentially the same, except HDMI has:

• Support for 8 channels of audio
• Support for the YUV colour space
• CEC (wiring to enable remote control between devices)
• A different connector

Is HDMI compatible with DVI?

Yes - although not DVI-A. You can buy DVI to HDMI cables and send video signals between devices. However, the DVI device must be HDCP enabled for this to work.

What is the difference between HDMI and component video cables?

HDMI cables are audio/video interconnects that send digital signals between AV devices. Component video cables send component analog signals between devices and are restricted to video only - they do not send audio signals.

Can I convert a component video output to HDMI?

Not easily/cheaply. You cannot simply have a component video to HDMI cable/adaptor as one is an analog signal and the other is digital. You can buy converter boxes but these can be expensive. Many AV receivers have the ability to upconvert a component input to an HDMI output.

Do I need to buy a new cable for my 3D TV?

Probably not. If you already have a 'high speed' category 2 HDMI cable then this will support all the requirements of HDMI 1.4 and 3DTV signals (with one exception - see below). A standard category 1 cable hasn't been tested to support the higher data rates, and so may not be reliable enough.

However, one part of the new HDMI 1.4 specification will require a new cable. The 1.4 update supports an ethernet connection through HDMI. To utilize this in your equipment, you will need a category 1 or 2 HDMI cable 'with ethernet'.

the HOME CINEMA GUIDE
HDMI Cable Store HDMI Switcher Store HDMI Splitter Store HDMI Matrix Store	HDMI Cable Shop HDMI Switch Shop HDMI Splitter Shop HDMI Matrix Shop
STORES

Have Your Say:

Did we miss something? Got something to say? Ask your own question about HDMI here - or just add your own comments about this page.

Please give as much detail as you can - we may not be able to use very short submissions with little information.

What others have said...

Follow the links below to see what other visitors have asked about HDMI. Don't forget to add your own comments...

Back to: Home Theater Wiring from HDMI FAQ

Back from HDMI FAQ to Home Cinema & Home Theater Guide Homepage

back to top