I thought I would share some info from HDMI.org, it is a great site and has a lot of useful information.
There is a lot of misinformation out there regarding which version of cable you need, and it can be a bit confusing at times. I figured I would post some of the most common FAQ's here. I am sure most people who view this site are very knowledgeable when it comes to HDMI, but there's the chance we might learn something new. Here are the basics:
"Q. What is HDMI?
HDMI (High-Definition Multimedia Interface) is the first and only industry-supported, uncompressed, all-digital audio/video interface. By delivering crystal-clear, all-digital audio and video via a single cable, HDMI dramatically simplifies cabling and helps provide consumers with the highest-quality home theater experience. HDMI provides an interface between any audio/video source, such as a set-top box, DVD player, or A/V receiver and an audio and/or video monitor, such as a digital television (DTV), over a single cable.
HDMI supports standard, enhanced, or high-definition video, plus multi-channel digital audio on a single cable. It transmits all ATSC HDTV standards and supports 8-channel, 192kHz, uncompressed digital audio and all currently-available compressed formats (such as Dolby Digital and DTS), HDMI 1.3 adds additional support for new lossless digital audio formats Dolby® TrueHD and DTS-HD Master Audio™ with bandwidth to spare to accommodate future enhancements and requirements.
- HDMI is the de facto standard digital interface for HD and the consumer electronics market: More than 700 companies have become adopters, and nearly 200 million devices featuring HDMI are expected to ship in 2008, with an installed based of nearly one billion HDMI devices by 2010 (conservative estimates by In-Stat).
- Convergence – HDMI is the interface for convergence of PC and consumer electronics devices: HDMI enables PCs to deliver premium media content including high definition movies and multi-channel audio formats. HDMI is the only interface enabling connections to both HDTVs and digital PC monitors implementing the DVI and HDMI standards.
- Evolving standard – HDMI is continually evolving to meet the needs of the market: Products implementing new versions of the HDMI specification will continue to be fully backward compatible with earlier HDMI products.
Q. What is the difference between HDMI 1.3 and HDMI 1.3a, or 1.3b?
For consumers, there is no difference between HDMI version 1.3 and 1.3a or 1.3b. These minor revisions to the specification typically relate to manufacturing or testing issues and do not impact features or functionality. In addition, HDMI Licensing, LLC is actively working with manufacturers to reduce confusion for consumers by de-emphasizing version numbers and focusing instead on product features and functionality.
Q. What functionality was added to each version of HDMI?
The following provides an overview of major functionality added to each version of HDMI:
- Adds features and capabilities that increase HDMI's appeal for use in both the CE and PC industries. Specifically, the features and modifications for HDMI 1.2 include: Support for One Bit Audio format, such as SuperAudio CD's DSD (Direct Stream Digital), changes to offer better support for current and future PCs with HDMI outputs, including: availability of the widely-used HDMI Type A connector for PC sources and displays with full support for PC video formats, ability for PC sources to use their native RGB color space while retaining the option to support the YCbCr CE color space, requirement for HDMI 1.2 and later displays to support future low-voltage (i.e., AC-coupled) sources, such as those based on PCI Express I/O technology.
- Consumer Electronic Control (CEC) features and command sets and CEC compliance tests are now fully specified.
- Creation of version 1.2a of the HDMI Compliance Test Specification (CTS), which includes a CEC Supplement. HDMI CTS 1.2a has been updated for technical consistency with HDMI Specification 1.2a as well as to the recently released HDMI Specification 1.2.
- Significantly, CTS 1.2a contains additional cable and connector testing and Authorized Testing Center (ATC) submission requirements. Specifically, under CTS 1.2a, the Adopter shall submit for testing to the ATC any new HDMI cable whose length exceeds previously tested cables.
- Additionally, HDMI Licensing, LLC will maintain a list of approved connectors. For a device to pass CTS 1.2a testing at an ATC, all connectors on such device must appear on the approved connector list. To add a connector to this list, the vendor must submit to the ATC or HDMI Licensing, LLC full and passing testing results.
- Higher speed: HDMI 1.3 increases its single-link bandwidth to 340 MHz (10.2 Gbps) to support the demands of future HD display devices, such as higher resolutions, Deep Color and high frame rates. In addition, built into the HDMI 1.3 specification is the technical foundation that will let future versions of HDMI reach significantly higher speeds.
- Deep Color: HDMI 1.3 supports 10-bit, 12-bit and 16-bit (RGB or YCbCr) color depths, up from the 8-bit depths in previous versions of the HDMI specification, for stunning rendering of over one billion colors in unprecedented detail.
- Broader color space: HDMI 1.3 adds support for “x.v.Color™” (which is the consumer name describing the IEC 61966-2-4 xvYCC color standard), which removes current color space limitations and enables the display of any color viewable by the human eye.
- New mini connector: With small portable devices such as HD camcorders and still cameras demanding seamless connectivity to HDTVs, HDMI 1.3 offers a new, smaller form factor connector option.
- Lip Sync: Because consumer electronics devices are using increasingly complex digital signal processing to enhance the clarity and detail of the content, synchronization of video and audio in user devices has become a greater challenge and could potentially require complex end-user adjustments. HDMI 1.3 incorporates automatic audio synching capabilities that allows devices to perform this synchronization automatically with total accuracy.
- New HD lossless audio formats: In addition to HDMI’s current ability to support high-bandwidth uncompressed digital audio and all currently-available compressed formats (such as Dolby® Digital and DTS®), HDMI 1.3 adds additional support for new lossless compressed digital audio formats Dolby TrueHD and DTS-HD Master Audio™.
HDMI Ethernet Channel – Adds high-speed networking to an HDMI link, allowing users to take full advantage of their IP-enabled devices without a separate Ethernet cable
Audio Return Channel – Allows an HDMI-connected TV with a built-in tuner to send audio data "upstream" to a surround audio system, eliminating the need for a separate audio cable.
3D – Defines input/output protocols for major 3D video formats, paving the way for true 3D gaming and 3D home theater applications
4K Support – Enables video resolutions far beyond 1080p, supporting next-generation displays that will rival the Digital Cinema systems used in many commercial movie theatres.
Content Type – Real-time signaling of content types between display and source devices, enabling a TV to optimize picture settings based on content type.
Additional Color Spaces – Adds support for additional color models used in digital photography and computer graphics.
HDMI Micro Connector – A new, smaller connector for phones and other portable devices, supporting video resolutions up to 1080p.
Automotive Connection System – New cables and connectors for automotive video systems, designed to meet the unique demands of the motoring environment while delivering true HD quality.
Q. What is the difference between a “Standard” HDMI cable and a “High-Speed” HDMI cable?
Recently, HDMI Licensing, LLC announced that cables would be tested as Standard or High-Speed cables.
- Standard (or “category 1”) HDMI cables have been tested to perform at speeds of 75Mhz or up to 2.25Gbps, which is the equivalent of a 720p/1080i signal.
- High Speed (or “category 2”) HDMI cables have been tested to perform at speeds of 340Mhz or up to 10.2Gbps, which is the highest bandwidth currently available over an HDMI cable and can successfully handle 1080p signals including those at increased color depths and/or increased refresh rates from the Source. High-Speed cables are also able to accommodate higher resolution displays, such as WQXGA cinema monitors (resolution of 2560 x 1600).
What are the new cables that have been introduced as part of HDMI 1.4?
HDMI Ethernet Channel functionality adds a new data channel, so new cables are required to support Ethernet connectivity. These two new cable types are Standard HDMI with Ethernet and High Speed HDMI with Ethernet, with the former supporting resolutions up to 1080i/720p, and the latter built for resolutions of 1080p or higher. Both cable types support a full-duplex 100 Mb/sec Ethernet connection.
The other new cable type is the Standard Automotive HDMI cable, designed for use in automotive video systems. It is a robust cable designed to handle the unique stresses of the motoring environment, such as vibration and temperature extremes, and will be tested to higher performance standards than other cables.
What are the types of HDMI cables?
In the HDMI specification, cables are specified in two categories (Standard and High Speed) according to their supported speed. Each can be made either with or without the HDMI Ethernet Channel. The 4 resulting cable types are then:
- Standard HDMI Cable
- High Speed HDMI Cable
- Standard HDMI Cable with Ethernet
- High Speed HDMI Cable with Ethernet
There are also cable-types defined for automotive applications but these cables are not currently available to consumers.
What cable do I need?
- Use a standard cable if you have a lower-resolution display (approx. 720p or 1080i).
- Use a High Speed cable if you have higher-resolution display (e.g. 1080p). High Speed cables can deliver all video content currently defined for the HDMI standard (i.e. more than two 1080p/60 video streams, including 3D).
- Use an HDMI cable with Ethernet if your devices take advantage of the HDMI Ethernet Channel. HDMI cables with Ethernet are capable of sending 100/mbps over the HDMI Ethernet Channel."