HD DVD Reference

HD DVD Welcome to the HDTV Magazine HD DVD reference page. This page is based on our HD DVD Primer article published in February 2006. We will cover on this page a general overview of HD DVD technology as well as digging down to the specifics of the format and comparing those with the DVD format. You will also find below a list of compatible hardware/players and a list of current movie titles and their availability.
Page Summary:

General HD DVD Overview
Format Specifics & Comparisons
Hardware Available
Titles Available
Additional Links & Information

General HD DVD Overview

Laser Spectrum The basic disc structure is the same as DVD (size, layers, etc.), but the compression and laser technologies involved are completely different. Traditional DVD's utilized a red laser for reading to and writing from the disc. HD DVD utilizes a new blue-violet laser. This new blue-violet laser has a 405nm wavelength vs. the red laser's 650nm. This shorter wavelength allows for much higher data density since the blue laser can write a much narrower data track. The net effect is that HD DVD can store more than 3 times the number of bits as traditional DVD's.

HD DVD also utilizes more advanced compression techniques than did traditional DVD. It can employ MPEG-4 AVC and VC-1 (aka Windows Media 9), whereas traditional DVD's were strictly MPEG-2. These compression advances allow for roughly twice the data storage as traditional DVD. For a direct comparison of these two specifications, see the table below:

In addition to improved video, HD DVD also features expanded audio support. Traditional DVD provided support for AC-3 (Dolby^® Digital) and MPEG codecs. HD DVD has added Dolby^® Digital Plus (lossy) and DTS^® (lossy) as mandatory codecs. Support for 2-channel Linear PCM and 2-channel MLP (True HD) are also mandated. The HD DVD standard also allows for DTS^® HD (lossless) as an optional codec. With respect to the two currently available Toshiba units, the audio capabilities are equally as impressive as their video capabilities. Their press release says it best:

The mandatory audio formats for HD DVD include both lossy and lossless formats from Dolby Labs and DTS^® - including the newly developed Dolby^® Digital Plus and DTS-HD.

The lossless mandatory formats include Linear PCM and Dolby TrueHD (only 2 Channel support is mandatory). The TrueHD format is bit-for-bit identical to the high resolution studio masters and can support up to eight discrete full range channels of 24-bit/96k Hz audio. Another lossless format (specified as an optional format) is DTS-HD. This employs high sampling rates of up to 192kHz.

Both models feature built-in multi-channel decoders for Dolby Digital, Dolby Digital Plus, Dolby TrueHD (2 channel), DTS and DTS-HD. The HD-XA1 employs the use of four high performance DSP engines to decode the multi-channel streams of the wide array of audio formats. These high performance processors will perform the required conversion process, as well as the extensive on-board Multi-Channel Signal Management including: User Selectable Crossovers, Delay Management and Channel Level Management.

For content protection, HD DVD utilizes the Advanced Access Content System (AACS), which is a standard for content distribution and digital rights management. For media that is AACS-enabled, these players will be required to recognize an Image Constraint Token (ICT), inserted into the movie data, and scale the analog output (over component) down to 540p. This is still better than standard 480p DVD, but far from HD resolutions. As well as preventing illegal copying, AACS provides "Managed Copy", which essentially allows content transfer from the HD DVD to other device (like a home media server). The decision to ICT-enable content is up to each studio, and each studio is likely to go their own way.

Format Specifics & Comparisons

	DVD	HD DVD
Disc type	DVD-ROM (Read-Only)	HD DVD-ROM (Read-Only)	HD DVD-R (Recordable)	HD DVD-Rewritable (Recordable)
Disc diameter	120mm	120mm	120mm	120mm
Disc structure	0.6mm x 2 substrates	0.6mm x 2 substrates	0.6mm x 2 substrates	0.6mm x 2 substrates
Capacity (Single-sided, single-layer) (Single-sided, dual-layer)	4.7GB 8.5GB	15GB 30GB	15GB	20GB 32GB(Under development)
Playback time* Recording time*	4.7GB, SD resolution: 132minutes 8.5GB, SD resolution: 238minutes	15GB, HD resolution: over 4 hours 30GB, HD resolution: over 8 hours	15GB, HD resolution: over 4 hours	20GB, HD resolution: over 5.5 hours 32GB, HD resolution: over 8.5 hours
Laser Wavelength	650nm (red laser)	405nm (blue laser)	405nm (blue laser)	405nm (blue laser)
Compression technology	MPEG-2	MPEG-4 AVC/ VC-1/MPEG-2	MPEG-4 AVC/ VC-1/MPEG-2	MPEG-4 AVC/ VC-1/MPEG-2
User bit rate	11.08Mbps	36.55Mbps	36.55Mbps	36.55Mbps
Track pitch	0.74µm	0.40µm	0.40µm	0.34µm

Hardware Available

Originally, the only manufacturer that had HD DVD players on the market was Toshiba, but recently RCA has nudged into the market. The HD-XA1 ($799.99) and the HD-A1 ($499.99) are both backward-compatibile, allowing playback of older CD and DVD formats. Both players also support copy-protected playback via HDCP at 720p and 1080i over HDMI, and will scale a traditional 480p DVD source to either 720p or 1080i to match your television's capabilities.

Toshiba also has two second-generation HD DVD players coming out by the end of the year. The Toshiba HD-A2 ($499.99) and the HD-XA2 ($999.99) will both support more advanced audio, while the HD-XA2 will be the first player to support 1080p output and will be HDMI 1.3 compliant. Both models also load the media in about half the time of their first-generation counterparts and also sport an improved remote control.

While not a "player" in and of itself, Microsoft will be releasing the HD DVD add-on drive for the Xbox 360 in November 2006. This drive, when combined with the Xbox 360 Gaming Console will be fully compliant with the HD DVD specification and is rumored to support 1080p output via VGA connector.

	Output Resolution	HDMI Version	Avialability	Retail	Street
Toshiba HD-A1	720p, 1080i	1.1	Now	$499.99	$164.95
Toshiba HD-XA1	720p, 1080i	1.1	Now	$799.99	$279.00
Toshiba HD-A2	720p, 1080i	1.2a	October 2006	$499.99	$157.03
Toshiba HD-XA2	720p, 1080i, 1080p	1.3	December 2006	$999.99	N/A
RCA HDV5000	720p, 1080i	1.1	Now	$499.99	$359.99
Microsoft Xbox 360 HD DVD Add-on	720p, 1080i, 1080p	N/A	November 2006	$199.99	$119.99