Lossless audio - Dolby TrueHD

Lossless Audio for HD Surround Sound

Dolby TrueHD Lossless Audio: The Most Authentic HD Surround Sound

Dolby® TrueHD is a 100 percent lossless audio format that ensures you’ll experience movies and music that are identical to the studio masters, soundstage mixes, or concert recordings.

With support for up to 7.1 channels of dramatic high-definition (HD) surround sound, Dolby TrueHD lossless audio lets you experience the full potential of Blu-ray™ audio in your living room.

Watch the Dolby TrueHD Lossless Audio Video

Benefits 

Reproduces 100 percent lossless audio that is bit-for-bit identical to the studio master, so you hear the music, movie, or TV show just as its creators intended

Delivers up to 7.1-channel playback for the most realistic and immersing Blu-ray audio experience available from your home theater

Allows you to experience the full potential of HD entertainment on Blu-ray Disc™

Supports up to 16 discrete channels and offers expandability to accommodate more channels in the future

Lossless Audio for Studio-Master Quality

As a lossless audio codec, Dolby TrueHD ensures that the listener hears every nuance of a movie, television program, or music soundtrack, without any loss of quality.

On Blu-ray Disc, Dolby TrueHD supports up to eight full-range channels of 96 kHz/24-bit audio and six full-range channels of 192 kHz/24-bit audio, for perfect studio-master-quality lossless audio playback of high-definition movies, music, and television shows. The result is the most authentic audio experience available for your home theater system.

Where You’ll Find Dolby TrueHD

See the Products tab for the range of equipment and content available, along with specific examples.

The Ultimate High-Definition Surround Sound Experience

Dolby TrueHD is a lossless compression audio format that enables bit-rate efficiencies (disc and transmission) for a file size half that of uncompressed pulse-code modulation (PCM), while simultaneously delivering a 100 percent studio-master-quality reproduction of the original audio performance. As a result, Dolby TrueHD enables the best possible audio fidelity from Blu-ray Disc and streamed or downloaded media sources.

Features

Transfers data at bit rates of up to 18 Mbps for unmatched sound quality

Delivers up to 16 channels of pristine audio at studio-master quality

Maintains consistent dialogue levels when changing between Dolby TrueHD and Dolby Digital programming

Includes dynamic range control, enabling reduced peak volume levels without loss of overall sound quality—ideal for listening without disturbing others

Provides superior 7.1 downmix overload detection and protection

Gives the content creator the ability to include a companion Dolby Digital (640 kbps) 5.1-channel theatrical mix on 7.1-channel Dolby TrueHD titles

Advanced 96k Upsampling

Movie soundtracks and TV shows are generally recorded using a 48 kHz (48k) sampling frequency. To ensure clearer, more natural playback sound, Dolby has taken further steps by implementing a proven upsampling process developed by Meridian Audio.

This upsampling technique applies higher sample rates and increased playback quality through an advanced apodizing filter that masks undesirable digital artifacts introduced by the 48k analog-to-digital (A-to-D) conversion downstream in the recording process.

These artifacts, called preringing, add an unnatural harshness or edginess to the sound. Dolby upsampling results in a cleaner signal with a high sampling frequency that produces the highest-quality lossless Blu-ray audio from material originally recorded at 48k.

A Blu-ray Disc with Dolby TrueHD lossless audio brings you one step closer to what was captured by the microphones and the mixing board. You’ll hear the difference as more "air" and clarity, and a more natural ambience, particularly for high-frequency sounds.

Full compatibility with all Blu-ray players and A/V receivers means that you don’t need to add hardware or upgrade software.

World-class advanced 96 kHz (96k) upsampling provides a new measure of audio quality for movies and television programming.

An advanced apodizing filter masks digital audio artifacts introduced in the content-creation process, delivering clearer sound on Blu-ray Disc.

Blu-ray soundtracks achieve their optimum capability, further enhanced by A/V receivers equipped with 96k digital-to-analog (D-to-A) converters.

Dolby TrueHD Lossless Audio Specifications

Format: Lossless compression

Sampling frequency: 44.1 kHz to 192 kHz

Word length: Up to 24 bits

Data rate: Variable, up to 18 Mbps

Maximum channel support: 16 channels, as presently deployed

Blu-ray Disc channel support:

Up to eight channels of 96 kHz/24-bit audio

Six channels (5.1): up to 192 kHz/24-bit

Two- to six-channel support: up to 192 kHz/24-bit maximum bit rate, up to 18 Mbps on Blu-ray Disc

UltraViolet™ channel support: Up to eight channels of 96 kHz/24-bit audio

Support for multiple artistic mixes in a single data stream