Dolby® Digital Plus extends the capabilities of Dolby Digital, optimizing sound quality and efficiency for a richer, more compelling audio experience.
Delivers scalable sound, optimizing quality and efficiency for available bandwidth
Supports a wide range of existing and emerging home theater, broadcast, streamed content, and mobile applications
Provides up to 7.1 channels of surround sound for a more involving experience and dramatic special effects
Includes compatibility with millions of existing playback systems
Dolby Digital Plus is a versatile digital audio coding technology that extends the capabilities of Dolby Digital. Dolby Digital Plus delivers up to 7.1 channels of surround sound, with scalable sound delivery and a wide range of bit rates ensuring optimized sound quality and efficiency for the available bandwidth. These advances are just a few reasons why Dolby Digital Plus delivers a more enveloping audio experience for existing and emerging applications, including new digital broadcast TV formats, Internet-delivered audio, and high-definition video discs.
Dolby Digital Plus for Broadcast
By delivering increased efficiency that enables lower bit rates, support for up to 7.1 channels, and advanced services like bitstream mixing, Dolby Digital Plus gives broadcasters the flexibility they need to create a high-quality audio experience for existing and next-generation applications. Read more about Dolby Digital Plus for Broadcast.
Why Dolby
Dolby Digital Plus is the audio complement to today’s video compression technologies, such as H.264 (MPEG-4 AVC). Because Dolby Digital Plus offers up to 7.1 channels for existing and next-generation applications, broadcasters can now deliver more channels of surround sound over less bandwidth, providing a richer and more enveloping audio experience whether via HDTV, IPTV, cable, satellite, or terrestrial broadcast television.
Maintains high quality at more efficient bit rates
Enables interactive stream mixing of multichannel secondary audio, such as a director’s commentary, with the main theatrical soundtrack
Allows broadcasters to offer advanced services such as enhanced viewing options for the visually impaired
Integrates scalability that allows the bit rate to be configured for a specific broadcast system
Includes complete Dolby metadata support and backward compatibility with existing home theaters equipped with Dolby Digital audio
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
|
Professional
|
Consumer
|
| Program configuration |
x
|
|
| Program description text |
x
|
|
| 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 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
|
|
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 backwards compatibility with the existing Dolby Digital 5.1-channel home theater systems in use today.