Here's the scoop:
By Joseph Palenchar -- TWICE, 4/10/2006
New York — The first HD DVD players will decode all mandatory and optional surround sound formats outlined in the HD DVD specifications, and the players will deliver surround to consumers' existing A/V receivers through digital S/PDIF, HDMI 1.1 and 5.1-channel analog outputs, the HD DVD promotion group said.
Because the players will transcode all of the formats to 5.1-channel PCM with up to 96kHz/24-bit quality, the streams can be transported along with high-definition video via a single HDMI 1.1 cable to the handful of current A/V receivers with HDMI 1.1 inputs, a group spokesman said. Transcoding to uncompressed 96/24 PCM ensures the resulting sound quality will match the quality of the soundtracks in their native form, he said.
The players will transcode all surround formats to PCM for one reason: so they can be mixed by the player with menu sound effects and with optional directors' commentaries, which will reside on the disc in compressed form and be transcoded to PCM, the spokesman explained. PCM mixing will enable menu sounds and directors commentaries to be heard while a soundtrack is playing.
For A/V receivers lacking HDMI 1.1 inputs, the players will feature 5.1-channel analog outputs and will down-mix a 7.1-channel soundtrack to 5.1, the group said.
For consumers who don't want to connect six analog cables to enjoy a 5.1-channel stream, the players will also transcode all streams to DTS 5.1 for transport through a digital S/PDIF output, whose 1.5Mbps bandwidth will limit sound quality to what can be achieved with today's DVD players. Stereo analog outputs will also be provided.
The mandatory decoders that must appear in all HD DVD players are losslessly compressed two-channel Dolby True HD up to 96kHz/24-bit quality; a core 5.1-channel DTS HD lossy stream that's compatible with existing 1.5Mbps DTS 5.1 decoders in A/V receivers; and lossy Dolby Digital Plus at data rates up to 3Mbps, including 5.1 and 6.1 variations. The players will convert Dolby Digital Plus to 5.1- and 6.1-channel Dolby Digital at a data rate up to 640Kbps for playback by existing Dolby Digital decoders.
All HD DVD discs must feature at least one of the three mandatory surround formats.
HD DVD's optional decoders are Dolby True HD with up to 7.1-channel 96/24-quality channels, losslessly compressed DTS HD Master with up to 5.1 192kHz/24-bit quality channels, and all optional variations of lossy DTS HD, including 6.1- and 7.1-channel soundtracks with up to 192kHz/24-bit quality at data rates up to 3Mbps.
The next generation of HD DVD players will likely feature 7.1-channel analog outputs and perhaps HDMI 1.3 outputs. The latter would enable all surround codecs to be transported in native form to future HDMI 1.3-equipped outboard decoders or A/V receivers with built-in decoders, the spokesman said.
HDMI 1.1 is capable of transporting all HD DVD and Blu-ray audio formats in native form except for losslessly compressed DTS HD Master and Dolby True HD, whose 768kHz “frame rates” exceed HDMI's 192kHz frame-rate capability, the HDMI licensing organization previously told TWICE.
One of the first Blu-ray players, Sony's $1,000 model, decodes Blu-ray's mandatory codecs — Dolby Digital 5.1, DTS 5.1 and six-channel 192kHz/ 24-bit uncompressed PCM — for transfer in native form through the player's HDMI 1.1 output and through six analog outputs.
Dolby Digital and DTS also stream through the players' S/PDIF, which also carries six-channel PCM soundtracks after down-conversion to two-channel PCM.
The player doesn't support Blu-ray's optional surround codecs, some of which require HDMI 1.3 outputs for transfer in native form to future outboard decoders or A/V receivers with 1.3 inputs, the company said.
Although some companies have considered modifying the HDMI 1.1 spec to deliver some of the optional codecs in native form to outboard decoders, Sony said it doesn't plan to go off-standard.
The publication of the HDMI 1.3 spec is tentatively set for June.
Panasonic has announced September shipments of its first Blu-ray player, the DMP-BD10, but said it doesn't have details on the device's supported surround formats and A/V receiver connectivity.
Navigating HD DVD, Blu-ray Surround Formats
(Mandatory, Optional In Players)
