Dolby Digital Header

Audio Encoding/Decoding Technology

Dolby® Digital, also referred to as AC-3, is an advanced audio encoding/decoding technology that efficiently delivers up to 5.1 discrete channels of vibrant surround sound for broadcasting, home theater, cinema, PC, online streaming, and video game programming.

Enables the efficient storage and transmission of high-quality 5.1 digital surround sound

Immerses audiences in the on-screen action

Provides compatibility with millions of existing playback units

Dolby Digital ensures that your audience experiences a rich, enveloping surround sound experience by delivering up to 5.1 discrete audio channels.

Three front channels (Left, Center, and Right) provide crisp, clean dialogue and accurate placement of on-screen sounds, while twin surround channels (Left Surround and Right Surround) immerse the audience in the action.

The Low-Frequency Effects (LFE) channel delivers deep, powerful bass effects that can be felt as well as heard. As it needs only about one-tenth the bandwidth of each of the other channels, the LFE channel is referred to as a “.1” channel.

Already found in thousands of cinemas and millions of homes worldwide, Dolby Digital is the preferred standard in home theater surround sound today.

Why Dolby

Dolby Digital technology, also known as AC-3, is a sophisticated digital audio encoding technology that provides up to 5.1 channels of enveloping, engaging home theater surround sound.

Dolby Digital’s coding efficiency lets you deliver high-quality multichannel surround sound without compromising video quality. That’s why Dolby Digital is a designated global audio standard for DVD: virtually every DVD-Video player includes Dolby Digital decoding, with a digital output for 5.1-channel surround sound and stereo outputs for two-channel mixdowns of the Dolby Digital movie soundtrack.

Nearly 60 million digital cable and satellite set-top boxes are currently in use worldwide, supported by over 30 million audio/video receivers equipped with 5.1-channel Dolby Digital decoding.

Dolby Digital is also a standard audio codec for Blu-ray Disc™.

Whether high-definition (HD) or standard-definition (SD), all digital television (DTV) broadcasts use Dolby Digital audio in the US, Canada, and other countries that have adopted the ATSC television standard. Dolby Digital audio is also used in some countries, such as Australia, in conjunction with other transmission standards, and is an optional multichannel audio delivery format in DVB and direct-to-home (DTH) broadcasts in Great Britain and Europe.

That makes Dolby Digital the preferred multichannel audio standard worldwide for direct broadcast, DTH satellite, and digital cable systems, further expanding the market for home theater systems.

Dolby Digital Products

The Dolby Digital solution includes a complete suite of hardware products for encoding, decoding, content preparation, and audio synchronization.

Dolby Digital is also supported by Dolby Media Producer, the definitive suite of professional software designed to support all Dolby audio codecs used in mastering DVD-Video, DVD-Audio, Blu-ray Discs—and beyond.

Channels: 1.0 to 5.1, discrete

Data rate: 32–640 kbps, scalable

DVD data rate, 5.1-channel audio: 384 or 448 kbps

Blu-ray Disc data rate, 5.1-channel audio: 640 kbps

Supports Dolby metadata: Yes

Connections: S/PDIF, HDMI, IEEE 1394

Mixing/streaming capabilities: Yes

Dolby Metadata Parameters

Metadata Parameter
Informational
Control
Dialogue level  
x
Channel mode  
x
LFE channel  
x
Bitstream mode
x
 
Line mode compression  
x
RF mode compression  
x
RF overmodulation protection  
x
Center downmix level  
x
Surround downmix level  
x
Dolby Surround mode  
x
Audio production information
x
 
Mix level
x
 
Room type
x
 
Copyright bit
x
 
Original bitstream
x
 
Preferred stereo downmix  
x
Lt/Rt Center downmix level  
x
Lt/Rt surround downmix level  
x
Lo/Ro Center downmix level
 
x
Lo/Ro surround downmix level  
x
Dolby Digital Surround EX mode  
x
A/D converter type
x
 
DC filter  
x
Lowpass filter  
x
LFE lowpass filter  
x
Surround 3 dB attenuation  
x
Surround phase shift  
x


 
DOCUMENT LIBRARY
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