Dolby TrueHD
From Wikipedia, the free encyclopedia
Dolby TrueHD, from Dolby Laboratories, is an advanced lossless audio codec based on Meridian Lossless Packing. Dolby TrueHD can handle up to 14 discrete sound channels simultaneously. And TrueHD retains the metadata capability of Dolby Digital, allowing dialog normalization, Dynamic Range Control, and other content-dependent info to be embedded in the bitstream.
Dolby TrueHD competes with DTS-HD Master Audio, another lossless codec from Digital Theater System.
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[edit] TrueHD and high-definition optical disc
TrueHD is supported in both the HD DVD and competing Blu-ray Disc specification. While it is a mandatory codec for HD DVD, TrueHD is optional for BD-ROM. All HD DVD players are required to be capable of decoding TrueHD into a minimum of two channels of uncompressed audio, while BD players are not required to handle TrueHD at all. In both applications, TrueHD supports up to 8 discrete channels of 24 bit/96 kHz audio, at a maximum coded bitrate of 18 Mbit/s. The details of the bitstream differ between the two formats, due to the required presence of a AC-3 "core" bitstream in BD-ROM.
An HDMI 1.3 link is required for transport of the (raw) coded bitstream[1], although in practice, the lossless nature of TrueHD eliminates any potential difference between an HDMI 1.3 and HDMI 1.1 audio link. SPDIF/toslink cannot carry TrueHD at all, due to insufficient bitrate-capacity. Thus far, most HDMI-equipped players internally decode TrueHD to LPCM, and output the LPCM over HDMI.[2]. Fewer support analog-audio output or HDMI 1.3 output. All HD DVD players can transcode the TrueHD bitstream into a different format (such as DTS), providing a legacy AV receiver a high-quality approximation of the original TrueHD audio over the familiar SPDIF/toslink cable.
The Phantom of the Opera, released April 18, 2006 on HD DVD, was the first movie to offer a TrueHD soundtrack.
[edit] HD DVD titles with TrueHD
- The Phantom of the Opera
- Training Day
- Constantine
- Troy
- The Perfect Storm
- The Wicker Man
- End of Days
- Fear and Loathing in Las Vegas
- Charlie and the Chocolate Factory (isolated music-only track)
- Batman Begins
- V for Vendetta
- Superman Returns
- Lady in the Water
- Harry Potter and the Goblet of Fire (UK only)
- Clerks II
- Pulse
- Nine Inch Nails - Beside You in Time
- Poseidon'
- The Departed
- Happy Feet
- The World's Fastest Indian
- Feast (release on April 17)
- School for Scoundrels (release on April 17)
- Alpha Dog (release on May 1)
- Manilow Live!
- Heart: Alive In Seattle
- Nature's Colors With The World's Greatest Music
[edit] Blu-ray Disc titles with TrueHD
- Nine Inch Nails - Beside you in Time
- LEGENDS OF JAZZ with Ramsey Lewis "Showcase"
- LEGENDS OF JAZZ with Ramsey Lewis "Showcase" Product Site
