HDMI stands for High Definition Multimedia Interface. B […]
HDMI stands for High Definition Multimedia Interface. Before HDMI became common, to transfer the digital video signal from a source to a TV, the source had to convert the signal from digital to analog, this resulted in some information loss.
However, an HDMI output can transfer a digital video source signal digitally, without conversion to analog. This results in a pure transfer of all of ?video information from the digital video source to a HDMI or DVI (via a connection adapter) equipped TV.
In addition, HDMI can transfer both video and audio signals.
HDMI can pass video resolutions from 480i up to 4K (8K is on the way). However, each manufacturer determines the parameters for what is to be transferred via HDMI in their components.
HDMI can be implemented on Televisions, AV Receivers, DVD Players, Blu-ray Disc Players, HD-DVD Players, HD Cable Boxes, and HD Satellite Boxes.
HDMI also includes provisions for HDCP (High Definition Copy Protection). This allows content providers to prevent their programming from being illegally copied.
HDMI can be adapted to DVI (Digital Video Interface), via adapter cable or connector. However, the device that has the DVI connection must be HDCP enabled for the signal transfer to work.
There are several versions of HDMI that have been developed over the years. In each case the physical connector is the same, but the content characteristics have evolved.
Depending on when you purchased an HDMI-enabled component (HDTV, DVD player, Blu-ray Disc player, etc...) would determine what HDMI version you have. All newer versions are backwards compatible. You can still use newer versions of HDMI with components equipped with older versions, you just won't be able to access the all the features of the newer version(s).
IMPORTANT NOTE: Although the various versions of HDMI are able to access the features listed, not all home theater components touted as being compliant with a specific version of HDMI will automatically provide all those features. Each manufacturer can pick-and-choose what features from their selected version of HDMI they want to incorporate into their products.
HDMI 1.0 combines a digital video signal (standard or high-definition) with a two-channel audio signal over a single cable, such as between an HDMI-equipped DVD player and Television.
This version adds the ability to transfer not only video and two-channel audio over a single cable, but also added the ability to transfer Dolby Digital, DTS, and DVD-Audio surround signals, as well up to 7.1 channels of PCM audio.
This version of HDMI adds the ability to transfer SACD signals in digital form from a player to a receiver.
This version includes improvements in both audio and video capability. With the advent of Blu-ray Disc and HD-DVD, version 1.3 adds the ability to transfer the digital bitstreams for the new high resolution audio formats: Dolby Digital Plus, Dolby TrueHD, and DTS-HD Master Audio.
In addition to the above audio improvements, HDMI 1.3 and 1.3a increase the amount of video bandwidth that can be transferred from a source to a display.
This means, that in addition to the standard 24-bit color depth we are used to, HDMI 1.3 and 1.3a have the ability to transfer color depths up to 48-bits, and can accommodate resolutions much higher than the 1080p resolution standard that is in use today.
HDMI version 1.4 adds practical enhancements for HDMI connectivity. If home theater components, such as HDTVs, Blu-ray Disc players, and Home Theater Receivers, are HDMI 1.4 enabled, one or more of the following features can be implemented:
HDMI Ethernet Channel: This adds internet and home network connectivity to HDMI. In other words, both Ethernet and HDMI functions are available within a single cable connection.
Audio Return Channel: This may be the most practical application of HDMI 1.4. What this feature provides is a single HDMI connection between a TV and a home theater receiver that can not only pass audio/video signals from the receiver to the TV, but also pass audio originating from the TV's tuner to the receiver. In other words, when listening to audio accessed by the TV's tuner, you don't need a separate audio connection going from the TV to the home theater receiver.
3D Over HDMI: HDMI 1.4 is designed to accommodate 3D Blu-ray Disc standards, with the capacity of passing two simultaneous 1080p signals using one connection. NOTE: An update (HDMI 1.4a) also incorporates additional 3D TV Broadcast, Cable, and Satellite formats.
4Kx2K Resolution Support: Although the current high definition standard for consumer equipment tops out at 1920x1080 (1080p), HDMI 1.4 can accommodate future 3840x2160 and 4096x2160 high definition pixel resolutions (limited to 30hz frame rate).
Expanded Support For Color Spaces: This allows better color reproduction when displaying digital still photos from HDMI-connected Digital Still Cameras.