Audio Video News

If you've been reading UAV's reviews you know that while 1080p displays are proliferating, the ability of these displays to actually accept a 1080p native signal is a rarity. And if you've been following our coverage of the next-gen disc formats you also know that DTS and Dolby have cooked up new audio formats that aren't based on the lossy compression schemes we've been living with on DVD for years. All of these developments are intertwined with the HDMI specs, as HDMI will be the carrier for both 1080p video and the new audio codecs. Here's the latest on what it all means.

HDMI specs have indeed continued to evolve. According to the HDMI Licensing LLC, version 1.2a was complete just before CES, and version 1.3 is anticipated to be locked down in the first half of this year. Despite speculation in some corners that only the most recent versions of the HDMI spec support 1080p, HDMI Licensing 's Leslie Chard informed me that all versions of the HDMI spec support 1080p video at 60Hz. It is up to the manufacturers of displays and other HDMI compliant devices to include support for 1080p throughout the architecture of the piece- the HDMI receivers, video decoders, video D-A converters, and all the video processing involved must support 1080p throughout. Given that 1080p sources aren't yet on the market, many display manufacturers seemingly have chosen not to absorb the expense in developing 1080p architectures throughout their displays.

Regarding when we're going to see 1080p, HD DVD's representative have indicated to me that at least the format's initial releases will be 1080i, not 1080p. Blu-ray titles however, have been specified in press releases as 1080p. We'll see. Given how few displays can accept 1080p native, and the specter of down-rez'd analog outputs haunts both formats, it's uncertain how the many people without 1080p native-compatible displays will get such a signal off of the discs that carry it. The processing involved in converting 1080p to 1080i seems extensive, and I've received no word as to whether players from either format will support such a provision- a provision that seems critically necessary for a good number of early adopters.

Dolby Digital Plus, Dolby TrueHD, and DTS' DTS-HD are the next-gen audio codecs that will be offered with HD DVD and Blu-ray. Both Dolby Digital Plus and DTS-HD will have backward-compatible core 5.1-channel soundtracks imbedded in their signals that can be carried over standard S/PDIF digital interfaces and decoded by the current generation DTS and Dolby Digital decoders in our AVRs and surround processors. Both formats are scalable and will offer much higher data rates than the current lossy formats, and both DTS and Dolby are offering full lossless compression formats with bit-for-bit reconstruction. Dolby's TrueHD uses Meridian Lossless Packing , while DTS' lossless format is the proprietary DTS-HD Master Audio. On HD DVD and Blu-ray both codecs will boast lossless coding for up to eight discrete channels of audio at resolution at least as high as 24-bit/96kHz. The catch is that the new codecs will only be carried digitally in their native form over HDMI 1.3.

This raises obvious questions given that HD DVD players are due in stores next month, while the HDMI 1.3 spec is due only for the first half of 2006. Blu-ray players are also targeted for the first half of '06, and the announcements we've seen for players indicate April to June. How can players incorporate a spec that isn't complete? Ditto goes for any HDMI-compatible surround processor released before the HDMI 1.3 spec is done.

Advisor to the Toshiba HD DVD Group Mark Knox offered a few potential answers. One, he intimated at CES 2006 that it's most likely that the initial HD DVD releases will have current standard DTS and Dolby Digital soundtracks, but at the highest data rates possible (DVDs usually run at lower audio rates to save more bits for the video transfer). Also, six channel analog outputs will be provided on the players, which could be used with the analog multichannel pass-through connectors found on many current AVRs and surround processors.

Going further, Knox also noted that HD DVD players will have the ability to "transcode" the new high-res Dolby and DTS formats to PCM, which can then be carried over the current HDMI spec and should be compatible with a number of current HDMI compatible surround processors and AVRs. Some Blu-ray titles have also been announced as carrying uncompressed digital audio soundtracks as well, which most likely means uncompressed PCM. HD DVD is also spec'd to carry up to eight discrete channels of uncompressed PCM at resolutions up to 24/96, while Blu-ray is spec'd to go all the way up to 24/192.

Knox also informed me that HD DVD players will be software updateable, but it is not yet known for certain that updating to HDMI 1.3 will be a software switch or whether new hardware will be required. All of this news, and the recent revelation that the AACS copy protection scheme to be used by both formats was just completed in the last couple of weeks, raises the question of whether either of these formats is fully complete and ready for prime time. Is the rush to market for both formats increasing the possibility that early adopters may not be able to take advantage of all the new features the new formats promise?

These questions and many others will be answered in the coming months. All we know for now is that it's dicey time to be buying a new disc player or a new surround sound processor or AVR, and formats themselves aren’t likely to be only points of confusion facing consumers as HD DVD and Blu-ray come to market.