Dolby Digital Plus

Dolby® Digital Plus is the no-compromise standard for delivery of up to 7.1 channels of sound via cable, satellite, terrestrial, IPTV, and over-the-top (OTT) services. With 7.1 discrete channels of audio, Dolby Digital Plus brings the renowned Dolby cinema experience home.

What's more, Dolby Digital Plus enables cinematic sound across a new generation of entertainment devices, from televisions to phones to laptops. (It's in more than 640 million devices and counting.)

Broadcaster Benefits

Broadcasters can now deliver more channels of surround sound over less bandwidth. Dolby Digital Plus brings the following benefits to broadcasters:

Provides the same quality of audio as Dolby Digital, but with lower bandwidth

Supports a wide range of existing and emerging home theater, broadcast, streamed content, and mobile applications

Includes complete Dolby metadata support and backward compatibility with Dolby Digital home theater systems

Allows broadcasters to offer advanced services such as enhanced viewing options, including audio description for the visually impaired

Enables interactive stream mixing of multichannel secondary audio, such as a director's commentary, with the main theatrical soundtrack

Dolby Digital Plus is the ideal audio partner to complement the broadcaster's transition to H.264 video.

Consumer Benefits

Dolby Digital Plus has been designed to enhance the home theater experience, and provides the following benefits to consumers:

Brings cinematic surround sound within reach of a new generation of media devices

Optimizes sound quality for a richer, higher quality audio experience

Is backward-compatible with Dolby Digital home theater systems

Provides up to 7.1 channels of surround sound for dramatic special effects and a more involving experience

Can deliver audio description for the visually impaired at the same time as surround sound (the only audio codec capable of this)


Dolby Digital Plus decoders are already installed in more than 640 million consumer playback devices, are backward-compatible with Dolby Digital home theater systems, and can decode the Dolby Digital format.

No matter how it’s delivered, Dolby Digital Plus provides a no-compromise codec for a no-compromise experience. Contact us to find out more.

Solutions for Professional Partners

Integrate Dolby technologies into your products. We offer comprehensive solutions for both hardware and software products.

Dolby Digital Plus Specifications


Channels: 1.0 to 7.1, discrete

Data rate: 32/48 kbps–6 Mbps, scalable

Supports Dolby metadata: Yes

Connections: S/PDIF, HDMI, IEEE 1394

Mixing/streaming capabilities: Yes

Backward Compatibility: Yes; S/PDIF to legacy A/V receivers

Dolby Metadata Parameters

Professional metadata parameters are only carried in the Dolby® E bitstream and are used to configure a downstream decoder. Consumer parameters are carried in the Dolby E, Dolby Digital Plus, and Dolby Digital bitstreams, and are used by the consumer’s decoder.

Extended bitstream information parameters are in italics.

Metadata Parameter

Program configuration


Program description text


Dialogue level


Channel mode


LFE channel


Bitstream mode


Line mode compression


RF mode compression


RF overmodulation protection


Center downmix level


Surround downmix level


Dolby Surround mode


Audio production information


Mix level


Room type


Copyright bit


Original bitstream


Preferred stereo downmix


Lt/Rt Center downmix level


Lt/Rt surround downmix level


Lo/Ro Center downmix level


Lo/Ro surround downmix level


Dolby Surround EX mode


A/D converter type


DC filter


Lowpass filter


LFE lowpass filter


Surround 3 dB attenuation


Surround phase shift



Special Parameters

There are other professional parameters included in the Dolby E bitstream that are not under direct user control, such as timecode and pitch shift.

Dolby Digital Plus

Dolby Digital Plus is a highly sophisticated and versatile audio codec based on Dolby Digital and designed specifically to adapt to the changing demands of future audio, video delivery, and audio storage systems while simultaneously retaining backward compatibility with the existing Dolby Digital 5.1-channel home theater systems in use today.

Choose from the drop-down menus below to get Dolby professional reference material.