I glanced briefly at your AV123 thread and had another thought... You might want to take a few minutes to peruse my
HDMI FAQ . It is intended to serve as a fairly complete single-point source of information about HDMI's various forms without getting
too in depth with the technology. Basically, there are several scenarios with HDMI audio and the new HD optical disc formats (HD-DVD and Blu-ray): carry the new audio formats (Dolby Digital Plus, Dolby TrueHD, and DTS-HD) over HDMI as multichannel PCM (decoded by the player but left in the digital domain), carry the new audio formats in their native bitstreams for decoding by the receiver or processor, decode the new audio formats and convert them to analog in the player, or decode the new audio formats and convert them to either high-bitrate DTS or high-bitrate Dolby Digital for output over SPDIF (coaxial or optical digital audio). Which of those four actually takes place depends on
entirely too many factors (not the least of which is which formats are actually supported by the player). Many people have assumed that HDMI v1.3 was the holy grail and that once it was here we would go back to the old familiar bitstream output - feed the new formats in their native data form to the receiver or processor over HDMI instead of SPDIF. In reality, we may
still need the player to decode to multichannel PCM in order to support bonus material or other player features. The most recent information I've seen suggested that HD-DVD's may actually continue to force internal decoding for a while in order to allow things like player-generated sound effects during menu navigation. That multichannel PCM is supported by HDMI v1.1, which would have probably appeared in products much sooner if v1.3 hadn't been looming on the horizon. Overall, it's just plain messy...