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The High-Definition Multimedia Interface (HDMI) is an industry-supported, uncompressed, all-digital audio/video interface. HDMI provides an interface between any compatible digital audio/video source, such as a set-top box, a DVD player, or an A/V receiver and a compatible digital audio and/or video monitor, such as a digital television (DTV).

HDMI FAQ

Contents:
General HDMI Questions
Becoming an Adopter
Features of HDMI Specifications
HDMI 1.3
Compliance Testing
Compatibility and Interoperability
Connectors and Cables
Content Protection
HDMI Government Mandates

General HDMI? Questions

Q: What is HDMI?
Q: Who supports HDMI?
Q. What are the advantages of HDMI over existing analog interfaces such as composite, S-Video and component video?
Q. What is the life expectancy of HDMI?
Q. How can a consumer identify which HDMI products support a specific feature, such as DVD Audio or deep color?

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 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 400 companies have become adopters, and more than 60 million devices featuring HDMI are expected to ship in 2006 (conservative estimate 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: Who supports HDMI?
The HDMI Founders include leading consumer electronics manufacturers Hitachi, Matsushita Electric Industrial (Panasonic), Philips, Sony, Thomson (RCA), Toshiba, and Silicon Image. In addition, HDMI has the support of major motion picture producers Fox, Universal, Warner Bros. and Disney, and system operators DirecTV, EchoStar (Dish Network) as well as CableLabs.

Q. What are the advantages of HDMI over existing analog interfaces such as composite, S-Video and component video?
Quality: HDMI transfers uncompressed digital audio and video for the highest, crispest image quality.
All-Digital: HDMI ensures an all-digital rendering of video without the losses associated with analog interfaces and their unnecessary digital-to-analog conversions.
Low-cost: HDMI provides the quality and functionality of a digital interface while also supporting uncompressed video formats in a simple, cost-effective manner.
Audio: HDMI supports multiple audio formats, from standard stereo to multi-channel surround-sound.
Ease-of-use: HDMI combines video and multi-channel audio into a single cable, eliminating the cost, complexity, and confusion of multiple cables currently used in A/V systems.
Intelligence: HDMI supports two-way communication between the video source (such as a DVD player) and the DTV, enabling new functionality such as automatic configuration and one-touch play.

Q. What is the life expectancy of HDMI?
HDMI is an evolving standard and changes to meet the needs of the market. HDMI has capacity to spare, and can incorporate new technology advancements and capabilities long into the foreseeable future.

Q. How can a consumer identify which HDMI products support a specific feature, such as DVD Audio or deep color?

The key for consumers to remember is that HDMI has consistently enabled a variety of the most innovative new technologies (whether they be DVD Audio, SACD, 1080p/60, etc.). However, in many cases, it is up to each manufacturer to choose which features to implement in any given product. The manufacturer can thus use its knowledge of the market to choose the mix of features that makes sense for its customers. So, customers must choose devices that have the features that they want (instead of focusing on which version of HDMI is implemented by the device.) . Consumers interested in confirming whether a particular consumer electronics product supports DVD-Audio or any other feature over HDMI are urged to review users’ manuals and product reviews and check with manufacturers directly.

HDMI Specifications

Q. When was the HDMI specification released?
Q. What functionality was added to each specification?
Q. What has been added in the HDMI 1.3 specification
Q. Are all of the new HDMI versions backwards compatible with previous versions?
Q. How can I get the latest HDMI Specification?

Q. When was the HDMI specification released?

The initial HDMI 1.0 specification was released in December 2002.
Version 1.1 was released in May 2004.
Version 1.2 was released in August of 2005.
Version 1.2a was released in December of 2005.
Version 1.3 was released in June of 2006.

Q. What functionality was added to each specification?

The following provides an overview of major functionality added to each version of HDMI

HDMI 1.1

• Support for DVD Audio

• 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)
o 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
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• 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.
???????????????????? o 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.

Q. What has been added in the HDMI 1.3 specification

Please see the HDMI 1.3 section below for more information on version 1.3

Q. Are all of the new HDMI versions backwards compatible with previous versions?

Yes, all HDMI versions are fully backwards compatible with all previous versions.

Q. How can I get the latest HDMI Specification?

Please visit the Manufacturer area of this site to download the HDMI Specification

Compatibility and Interoperability

Q. Is HDMI backward compatible with DVI (Digital Visual Interface)?
Q. What types of video does HDMI support?
Q. What version of HDMI does a consumer need to view 1080p content?
Q. Do you need a new version of HDMI to play Blu-ray and HD-DVD content in high definition?
Q. Are HDMI 1.0, 1.1 and 1.2 compatible with the next generation videogame consoles implementing 1080p and HDMI’s new deep color capability?
Q. What is HDMI’s new deep color capability?
Q. Does HDMI support Dolby 5.1 audio and high-resolution audio formats?
Q. Does HDMI support Dolby Digital, DTS, and high-resolution audio formats?
Q. Does HDMI support SACD?
Q. What is the most common compatibility problem among devices with HDMI connections?
Q. Some cable TV set-top boxes with HDMI outputs don’t deliver a picture to displays with HDMI inputs. What is the problem, and is there a solution?

Q. Is HDMI backward compatible with DVI (Digital Visual Interface)?

Yes, HDMI is fully backward compatible with DVI compliant devices. HDMI DTVs will display video received from existing DVI-equipped products, and DVI-equipped TVs will display video from HDMI sources. However, some older PCs with DVI are designed only to support computer monitors, not televisions. Consumers buying a PC with DVI should make sure that it specifically includes support for television formats and not just computer monitors.

Also, consumers may want to confirm that the DVI interface supports High-bandwidth Digital Content Protection (HDCP), as content that requires HDCP copy protection will require that both the HDMI and DVI devices support HDCP to properly view the video content.

Q. What types of video does HDMI support?

HDMI has the capacity to support existing high-definition video formats (720p, 1080i, and 1080p/60). It also has the flexibility to support enhanced definition formats such as 480p, as well as standard definition formats such as NTSC or PAL.

Q. What version of HDMI does a consumer need to view 1080p content?

HDMI has always supported 1080p resolution, starting from version 1.0 in 2002. However, as with many functions that HDMI enables (such as DVD-Audio and SACD), it is up to the manufacturer to choose whether to implement 1080p in the device. Some TV and device manufacturers have chosen not to implement 1080p in their products because 1080p content has not been widely available, and because changing the internal electronics of the device to support 1080p would increase cost.

Viewing 1080p resolution requires at minimum that the HDTV have a display supporting the 1080p pixel resolution. Today, many HDTVs use display technologies (such as PDP, LCD, and microdisplay screens) designed for 720p pixel resolution.

In addition, many of today’s 1080p HDTVs support only 720p or 1080i on the HDMI input, then perform video processing to up-convert the 720p/1080i signal to 1080p. This is now changing, as 1080p content is becoming increasingly available, and HDTVs fully supporting 1080p in the display and HDMI electronics have begun to reach the market in early 2006.

All versions of HDMI are backward compatible. Consumers should not look for a particular version of HDMI, but rather for the functionality that they want the device to support (SACD, 1080p, etc.).

Q. Do you need a new version of HDMI to play Blu-ray and HD-DVD content in high definition?

All versions of the HDMI specification support the ability to watch HD-DVD / Blu-Ray content in high definition up to 1080p resolution. However, there may be non-HDMI reasons that prevent some devices from accessing content in high definition, including lack of HDCP support.

Q. Are HDMI 1.0, 1.1 and 1.2 compatible with the next generation videogame consoles implementing 1080p and HDMI’s new deep color capability?

HDMI has been able to support 1080p content since version 1.0, and each new revision of the HDMI specification is fully backward compatible with previous revisions.

The HDMI Founders issued a press release during CES 2006 announcing that a future HDMI specification would expand the performance capabilities to support deeper color (up to 48-bit color RGB color) and higher resolution audio formats (such as Dolby TrueHD and DTS-HD). PCs and videogame consoles in particular are expected to be capable of delivering content that takes advantage of HDMI's latest capabilities. When such sources are interfaced to older HDMI HDTVs, the source should automatically select the highest quality video and audio performance supported by the HDTV.

Q. What is HDMI’s new deep color capability?

The new deep color capability lets manufacturers build devices allowing consumers to enjoy billions of colors with incredible visual clarity and detail. HDMI 1.3 supports 30-bit, 36-bit and 48-bit red/green/blue color depths and color space, an upgrade from the 24-bit maximum resolution in previous versions of the HDMI Specification.

Q. Does HDMI support Dolby 5.1 audio and high-resolution audio formats?

Yes. From the start, HDMI was defined to carry 8-channels, of 192kHz, 24-bit uncompressed audio, which exceeds all current consumer media formats. In addition, HDMI can carry any flavor of compressed audio format such as Dolby or DTS. (Such compressed formats are the only multi-channel or high-resolution audio formats that can be carried across the older S/PDIF or AES/EBU interfaces.) Additionally, most existing HDMI sources can output any compressed stream, and the newer sources can output uncompressed 6-channel, 96kHz audio from a DVD-Audio disk. There are A/V receivers on the market that can accept and process the 6- or 8-channel audio from HDMI.

Q. Does HDMI support Dolby Digital, DTS, and high-resolution audio formats?

Yes. From the start, HDMI was defined to carry 8-channels of 192kHz, 24-bit uncompressed audio, which exceeds all current consumer media formats. In addition, HDMI can carry any currently available flavor of compressed audio format such as Dolby (including Dolby Digital EX 7.1, Dolby Digital Plus 7.1, Dolby TrueHD) or DTS (including DTS-ES 6.1 and DTS-HD Master Audio). (Such compressed formats are the only multi-channel or high-resolution audio formats that can be carried across the older S/PDIF or AES/EBU interfaces). HDMI 1.3 adds additional support for new lossless digital surround audio formats Dolby TrueHD and DTS-HD Master Audio. Additionally, most existing HDMI sources can output any compressed stream, and the newer sources can output uncompressed 6-channel, 96kHz audio from a DVD-Audio disk. There are A/V receivers on the market that can accept and process the 6- or 8-channel audio from HDMI.

Q. Does HDMI support SACD?

HDMI has supported One Bit Audio format, such as SuperAudio CD's DSD (Direct Stream Digital), since version 1.2 (released in August, 2005). Customers interested in this feature should make sure that their device supports SACD.

Q. What is the most common compatibility problem among devices with HDMI connections?

The most common compatibility problems have to do with HDCP. Probably the most common failure is the lack of an HDCP repeater function or failure to perform the authentication reliably in all types of usage scenarios.

Q. Some cable TV set-top boxes with HDMI outputs don’t deliver a picture to displays with HDMI inputs. What is the problem, and is there a solution?

In some cases, the set top box software does not activate or support the HDMI port. In other cases, cable TV set-top boxes don’t work correctly when used in conjunction with an A/V receiver (but will typically function correctly when connected directly to a TV or monitor). Investigation of some of these devices reveals that this is caused by an error in the way these set top box devices implement HDCP. Specifically, some of those boxes do not support "HDCP repeaters" (devices that pass along the signal to another device) such as an A/V Receiver or switch. We believe that this may be a problem in the initial versions of these products, and in some cases there is new firmware available that fixes this issue in HDMI (newer versions may already have this fix). We have been actively working with manufacturers to resolve these problems. We suggest that users contact their cable operator and request the new software to address these issues.

Connectors and Cables

Q. Does HDMI accommodate long cable lengths?
Q. I need to connect two devices with 20 feet of cable, but the cable I bought doesn’t seem to work at that length.
Q. My HDMI cable sometimes falls out of the HDMI connector. Is anything being done to address this problem?

Q. Does HDMI accommodate long cable lengths?

Yes. HDMI technology has been designed to use standard copper cable construction at long lengths. In order to allow cable manufacturers to improve their products through the use of new technologies, HDMI specifies the required performance of a cable but does not specify a maximum cable length. Cable manufacturers are expected to sell reasonably priced copper cables at lengths of up to 15 meters. As semiconductor technology improves, even longer stretches can be reached with fiber optic cables, and with active cable technologies such as amplifiers or repeaters.

Q. I need to connect two devices with 20 feet of cable, but the cable I bought doesn’t seem to work at that length.

One solution is to buy a higher-quality cable. Another is to use an HDMI repeater.

Q. My HDMI cable sometimes falls out of the HDMI connector. Is anything being done to address this problem?

The combination of vertically-oriented connectors and heavy, thick-gauge cables appears have the potential of causing the connector to fall out. In some cases, it is due to the usage of a cable with a non-compliant, large connector over-molding that prevents proper connector engagement. The HDMI Founders are actively investigating a locking connector option that would be backward compatible with existing Type A connectors.

We have seen a few connectors that are out of spec (e.g., not the right size, too much over-molding, etc.), which led to compatibility issues and, in some cases, connector damage. However, we have started a connector certification program to help ensure that all Adopters use compliant connectors.

Content Protection Questions

Q. Does HDMI provide a secure interface?
Q. What is HDCP?
Q. If my digital monitor doesn’t have an HDCP-compatible connection (such as an HDMI connection with HDCP), will I be able to view HD DVD and Blu-ray content in high definition?
Q. I’ve read that the Hollywood studios are using Advanced Access Content System (AACS) to protect their high-definition content. Is AACS an alternative to HDCP?

Q. Does HDMI provide a secure interface?

While no security system is one hundred percent secure, HDMI, when used in combination with HDCP, provides an audio/video interface that meets the security requirements of content providers and systems operators.

Q. What is HDCP?

High-bandwidth Digital Content Protection (HDCP) is a technology developed by Digital Content Protection, LLC (a subsidiary of Intel) to protect digital entertainment content. HDCP has been implemented across both DVI and HDMI interfaces. The HDCP specification provides a cost-effective and transparent method for transmitting and receiving the highest quality digital entertainment content to DVI/HDMI-compliant digital displays.

The HDMI standard does not require HDCP. However, it is required by industry groups and governmental regulation (details below).

Q. If my digital monitor doesn’t have an HDCP-compatible connection (such as an HDMI connection with HDCP), will I be able to view HD DVD and Blu-ray content in high definition?

Content owners (i.e., a movie studio releasing a DVD) decide which technologies they will use to protect their content against unauthorized copying. Movie studios, which fear that high-definition versions of their movies will be pirated, are expected to use HDCP when releasing high-definition versions of their movies, though some may choose to release some titles without HDCP. To be safe, consumers who want to be able to play high-definition content should ensure that their HDTVs and other HD devices are able to decode HDCP-encrypted content.

There are also specific requirements on HDCP usage mandated by the U.S. Federal Communications Commission and by industry bodies in Europe and Asia. See below for more information.

With certain exceptions, nearly all HDMI devices on the market include HDCP support. DVI devices, in particular earlier versions of DVI, are more likely to lack HDCP support.

Q. I’ve read that the Hollywood studios are using Advanced Access Content System (AACS) to protect their high-definition content. Is AACS an alternative to HDCP?

No, the two are complementary. AACS is the content protection for the video on the DVDs and HDCP is the content protection on the HDMI link between the DVD player and the TV. AACS is a stronger replacement for the current content protection on today's standard-definition DVDs (which has been broken). The DVD player will decrypt the AACS-encrypted content coming off the HD-DVD or Blu-ray disc and then send the content over the protected HDMI link (using HDCP) to the HDTV.