The HDMI Licensing Knowledge Base is a library of current information about the HDMI standard. Select an appropriate category from the pull down below, or, you may use your own search terms to obtain results.
If your question involves a specific product, please contact the manufacturer directly. The HDMI Knowledge Base does not contain information about specific products.
Q. Can I use HDMI to connect one from to another using wall plates?
You can connect from one room to another using wall plate connections. However, the quality of the wall plate can affect the transmission. Be sure to select an HDMI-compliant wall plate that fits your specific installation requirements.
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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.
For Adopters, the latest HDMI Specification is v1.3a and the latest HDMI Compliance Test Specification (CTS) is 1.3c.
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Q. Does HDMI support Closed Captioning?
Close Captioning
The evolution from analog to digital TV has added some complexity to Close Captioning (CC). With one standard way of broadcasting/transmitting, decoding and displaying content NTSC or PAL, depending on region, analog TV made enabling CC fairly easy across CE devices since the TV was able to do all the CC decoding.
With the advent of digital TV and the introduction of digital HDTV services (cable, satellite, etc.) the responsibility of decoding CC has been taken away from the TVs and put into the various Set Top Boxes (STB) that are required for the majority of the digital HDTV services. Additionally, these STBs now have different ways of enabling CC making it complicated and creating confusion for consumers. All set-top boxes are required to support CC, however the implementation of CC can vary from one product to another. Enabling CC on a specific set-top box can be simple, or more difficult, depending on the implementation.
HDMI, LLC recommends contacting your TV service provider (cable, satellite, etc.) for the correct way to switch on its CC feature as a first step to resolve this issue. The second step is to contact the manufacturers directly for the correct way to enable the CC feature within your product.
HDMI and Close Captioning
Closed Captioning (CC) works differently with digital connections (HDMI, DVI, etc.)
How old analog CC worked:Source always sent CC information to the TV and the TV controlled whether the CC was displayed or not via the TV's remote (CC button). The CC button on the TV only controls CC for analog connections (S-Video, Composite, Component) or Over The Air tuners (ATSC digital or NTSC analog)
How CC works in HDMI and other digital connections:The TV remote's CC button does not enable/disable CC on HDMI sources. To enable CC, the user must enable it at the source either through a source remote control key (i.e. CC button) or by going through the setup menu of the source. The source will then combine the video content with the CC information and output that (video + CC) via HDMI to the TV.
The CC rendering is done at the source and not at the TV as it was with analog connections. For example, with a typical cable box the CC is enable by going to the cable box setup menu and not the TV remote's CC button. The TV remote's CC only controls the analog CC and does not control the CC for each of the HDMI source devices. CC must be enabled from each of the individual HDMI sources.
Exact steps to enable CC varies between manufacturers so please contact the source manufacturer for instructions.
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Q. What is the difference between Active HDMI and Passive HDMI?
There is no active or passive HDMI in the test specification. These terms apply to cables. Active cables have built-in electronics to enable long cable runs, and typically these cables require a power supply. These cables use active electronics to help push the signal farther than typical passive cables.
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Q. Is there support in the HDMI interface for closed caption information?
Closed captioning is available as long as the source supports and renders it.
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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.
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Q. Who supports HDMI?
The HDMI Founders include leading consumer electronics manufacturers Hitachi, Panasonic Corporation, 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.
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Q. What are the advantages of HDMI over existing analog video interfaces such as composite, S-Video and component video?
Quality: Because HDMI is a digital interface, it provides the best quality of the video since there are no lossy analog to digital conversions as are required for all analog connections (such as component or S-video). The difference is especially noticeable at higher resolutions such as 1080p. Digital video will be sharper than component, and eliminates the softness and ghosting found with component. Small, high contrast details such as text bring this difference out the most.
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. This is particularly beneficial when equipment is being upgraded or added.
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. By using HDMI, devices automatically deliver the most effective format (e.g 480p vs 720p, 16:9 vs 4:3) for the display that it is connected to - eliminating the need for the consumer to scroll through all the format options to guess what looks best.
HD Content-Ready: HDMI devices supporting HDCP have the comfort of knowing they will have access to premium HD content now and in the future. HD-DVD and Blu-ray have delayed the activation of the image constraint token (a.k.a. content protection flag) with today’s HD movies to help minimize potential issues caused by the transition, but are expected to activate this in a few years, meaning future HD movies will then not be viewable at HD resolutions over unprotected interfaces such as analog component.
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Q. What is the advantage of using HDMI over existing audio interfaces such as analog RCA connectors and digital SPDIF (coax and optical connectors)?
Quality: HDMI maintains the audio in its pure digital form all the way to the amplifier. Analog audio connections are more prone to losses depending on the cabling and other electronics of the audio rendering device. Compared to SPDIF connections, HDMI has significantly more bandwidth, allowing it to support the latest lossless audio formats such as Dolby TrueHD and DTS-HS Master Audio. These formats can not be supported over SPDIF connections due to their very high data rate requirements that exceed the capabilities of SPDIF. Please also see section on HDMI 1.3 for further details on Dolby TrueHD and DTS-HD Master Audio formats.
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. This is particularly beneficial when equipment is being upgraded or added.
Intelligence: HDMI supports two-way communication between the audio source (such as a DVD player) and the audio rendering device (such as an A/V receiver), enabling new functionality such as automatic configuration and one-touch play. By using HDMI, devices automatically deliver the most effective format (e.g Dolby Digital vs. 2 channel PCM) for the A/V receiver that it is connected to - eliminating the need for the consumer to scroll through all the audio format options to guess what is best and properly supported.
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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.
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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.
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Q. How do I get extra ports to plug in all of my devices if I only have 1 HDMI plug on my TV?
You might consider getting a switcher system with multiple plugs. Check out Gefen www.gefen.com
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Q. How can I find devices with HDMI v1.3 features?
The best way is to contact the Manufacturer directly. If you have a brand preference, please contact them directly. They will have information regarding availability and the feature set.
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Q. How will HDMI change the way we interface with our entertainment systems?
The most tangible and immediate way that HDMI changes the way we interface with our components is in the set-up. One cable replaces up to 11 analog cables, highly simplifying the setting up of a home theater as well as supporting the aesthetics of new component design with cable simplification.
Next, when the consumer turns on the HDMI-connected system, the video is of higher quality since the signal has been neither compressed nor converted from digital to analog and back.
Lastly, because of the two-way communication capabilities of HDMI, components that are connected via HDMI constantly talk to each other in the background, exchanging key profile information so that content is sent in the best format without the user having to scroll through set-up menus. The HDMI specification also includes the option for manufacturers to include CEC functionality (Consumer Electronics Control), a set of commands that utilizes HDMI’s two- way communication to allow for single remote control of any CEC-enabled devices connected with HDMI. For example, CEC includes one-touch play, so that one touch of play on the DVD will trigger the necessary commands over HDMI for the entire system to power on and auto-configure itself to respond to the command. CEC has a variety of common commands as part of its command set, and manufacturers who implement CEC must do so in a way that ensures that these common command sets interoperate amongst all devices, regardless of manufacturer.
CEC is an optional feature, however, so consumer interested in this functionality must look for CEC in the product feature list. Also, it is important to know that some manufacturers are creating their own proprietary names for their implementation of the CEC command set.
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Q. What are the HDMI-related questions consumers should ask when shopping for a new CE or PC device?
Several questions are key to evaluating HDMI on a CE component.
- How many inputs/outputs do I need?
- We are seeing more and more inputs and outputs on components as more and more people are connecting with HDMI. It is common to see 3 and 4 inputs on an HDTV – many with one input on the side or front for connecting to game consoles or other portable devices such as digital still cameras or camcorders. Always think about the number of sources and displays (or projectors) that could become part of your home theater system, and make sure the device you are evaluating has the number of inputs and outputs to support your needs over the near and long term.
- For those who have existing systems with one or two inputs, and are finding they need more, there are HDMI switches in the market that switch from multiple inputs (sources) to one output (to your display).
- Think features rather than HDMI version number.
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HDMI is constantly evolving to meet the needs of the marketplace. The standard is constantly adding more and more features that manufacturers can implement if they desire. But HDMI does not require manufacturers to implement everything that HDMI can do. HDMI provides a menu of capabilities and allows the manufacturer to choose which of those features make sense for its product line.
As a result, HDMI strongly recommends that consumers look for products with the features they want, rather than the version number of the HDMI components. Version numbers reflect capabilities, but do not correspond to product features. For example, if you want the new video features called Deep Color, look for Deep Color in the feature set rather than HDMI 1.3, the version of the specification that enabled Deep Color. Why? Because the version of the specification that enables Deep Color (1.3) does not mandate that Deep Color functionality be implemented.
However, it is important to also note that all HDMI versions are backwards compatible, so it does not matter what version of HDMI is in the component, all HDMI-enabled components will work together at the highest level of shared functionality.
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Q. As more and more devices converge, is HDMI an interface that can accommodate convergence between the PC and CE?
Absolutely. HDMI was developed using the same technology as DVI (Digital Visual Interface), the digital connection standard for the PC environment. So, HDMI is fully compatible with all DVI-enabled PCs (since HDMI offers both audio and video over one cable, and DVI carried only video, DVI-HDMI connectivity requires a separate audio cable).
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 – fully compatible with the hundreds of millions of DVI displays already in the market.
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Q. Are we seeing any adoption of HDMI in the PC space?
In 2007, the market started to see HDMI in many PC and PC-related devices. Major display manufacturers (like Samsung, BenQ, Viewsonic) have started to market PC displays with HDMI. Every major graphics card manufacturer (nVIDIA, ATI/AMD, Intel) has HDMI-enabled graphics cards on the market, as major PC manufacturers, including Samsung, Sony, HP, Dell and others have PCs on the market that have HDMI outputs.
- What is causing the sudden surge in PCs with HDMI?
- Notebooks, especially, have been quick to include the HDMI interface. With the advent of next generation DVD players in many notebooks, manufacturers need to accommodate the desire of many consumers to connect their new notebook to HDTVs to watch HD movies.
- The pervasiveness of HDMI – with HDMI as the digital connection of choice in all categories of CE devices, any and all PCs and PC-related products that may want to connect to the home theater environment must have HDMI in order to interconnect seamlessly.
- The HDMI connector is much smaller than DVI – making it a much more desirable connector, especially on a notebook where the size of a connector can be critical.
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