What version of HDMI is needed to play BluRay and HD-DVD content in High Definition?

What version of HDMI is needed to play BluRay and HD-DVD content in High Definition?

What version of HDMI is needed to play BluRay and HD-DVD content in high definition? First let's look at what HDMI is and does, and what the various versions support. We need to understand what HDMI means and what it does to understand what is needed to play this content.

HDMI stands for High Definition Multimedia Interface. This is an all-digital audio/video interface capable of transmitting uncompressed streams. HDMI has compatibility with the HDCP Digital Rights Management technology. High Definition Multimedia Interface provides an interface between any compatible digital audio/video source, like a set top box, a video game system, an A/V Receiver, or a personal computer, and/ or a video display monitor like a digital television. HDMI is a current replacement for the older analogue standards like SCART, Coax, Composite Video, Component Video, VGA, RCA connectors, and DVI-A, and the consumer electronics replacement for the older digital standards like DVI, which includes DVI-I and DVI-D.

HDMI will support any PC or TV video format, this includes standard, enhanced, or high-definition video, plus multi-channel digital audio on one single cable. It is independent of the various DTV standards such as ATSC, and DVB , as these are encapsulations of the MPEG movie data streams, which are passed to a decoder, and are output as uncompressed video data on HDMI. HDMI encodes the video data into TMDS for transmission digitally over HDMI.

When devices are manufactured, they adhere to various versions of the specification, where each version is given a number, such as 1.0 or 1.3. Each successive specification version uses the same cables, but it increases the capabilities, or the throughput, of what the cable can transmit. As an example, HDMI version 1.2 had a maximum pixel clock rate of 165MHz, which is sufficient to support 1080p at 60 Hz, but HDMI 1.3 increased that to 340MHz, and provides support beyond the highest resolution monitors available today.

HDMI also supports 8-channel uncompressed digital audio at 192kHz sample rate with 24 bits/sample as well as any compressed stream such as DTS or Dolby Digital. HDMI supports up to 8 channels of one-bit audio, such as what is used on Super Audio CDs, at rates up to 4 times what used by SuperAudio CD. With version 1.3, HDMI now also supports very high bitrate lossless compressed streams such as DTS-HD Master Audio and Dolby TrueHD.

Last year, 2006, two high definition optical disc formats were released that are in competition, HD DVD and Blu-ray Disc. These formats support higher fidelity audio than the old DVD format. These audio formats include Dolby Digital Plus, Dolby TrueHD and DTS-HD Master Audio. Not all of these formats are mandated by the HD DVD formats. High definition players provide numerous ways to transmit this audio. Today, the best fidelity is heard when the player is set to output LPCM over HDMI when using one of the higher fidelity formats. This method requires a preprocessor or audio/video receiver capable of handling multi-channel LPCM over HDMI. While this has been supported by the HDMI specifications since 1.0, not all devices that support HDMI 1.1 support this feature.

Every version of HDMI specifications supports the ability to watch BluRay or HD-DVD content in high definition up to 1080p resolution. There may other, non HDMI related reasons that may prevent some devices from accessing the content in high definition. This may include a lack of HDCP support. HDCP stands for High Bandwidth Digital Content Protection. This is a form of Digital Rights Management that was developed by Intel Corporation to control digital audio and video content as it travels across High-Definition Multimedia Interface or Digital Visual Interface connections. HDCP specification is proprietary and implementing HDCP requires obtaining a license first. HDCP is licensed by Digital Content Protection, which is a subsidiary of Intel. Licensees may not allow their devices to make any copies of content, and licensees must design their products to effectively frustrate any attempts to defeat the content protection requirements. The main purpose of HDCP is to prevent the transmission of non-encrypted high definition content. There are three ways this is done. The first system is an authentication process that disallows a non-licensed device to receive HD content. The second system is the encryption of the actual data that is sent over the DVI or the HDMI interface prevents any eavesdropping of information. It also prevents any "man in the middle" attacks. The third system includes key revocation procedures that ensure that any devices manufactured by vendors who violate the license agreement could be fairly easily blocked from receiving any HD data.