Audio Specifications
DVD-Audio offers many possible configurations of audio channels, ranging from single-channel mono to 5.1-channel surround sound, at various sampling frequencies and sample rates. (The ".1" denotes a Low-frequency effects channel (LFE) for bass and/or special audio effects.)
Compared to the Compact Disc, the much higher capacity DVD format enables the inclusion of either:
- Considerably more music (with respect to total running time and quantity of songs) or
- Far higher audio quality, reflected by higher linear sampling rates and higher bit-per-sample resolution, and/or
- Additional channels for spatial sound reproduction.
Audio on a DVD-Audio disc can be stored in many different bit depth/sampling rate/channel combinations:
| 16-, 20- or 24-bit depth | ||||||
|---|---|---|---|---|---|---|
| 44.1 kHz | 48 kHz | 88.2 kHz | 96 kHz | 176.4 kHz | 192 kHz | |
| Mono (1.0) | Yes | Yes | Yes | Yes | Yes | Yes |
| Stereo (2.0) | Yes | Yes | Yes | Yes | Yes | Yes |
| Stereo (2.1) | Yes | Yes | Yes | Yes | No | No |
| Stereo + mono surround (3.0 or 3.1) | Yes | Yes | Yes | Yes | No | No |
| Quad (4.0 or 4.1) | Yes | Yes | Yes | Yes | No | No |
| 3-stereo (3.0 or 3.1) | Yes | Yes | Yes | Yes | No | No |
| 3-stereo + mono surround (4.0 or 4.1) | Yes | Yes | Yes | Yes | No | No |
| Full surround (5.0 or 5.1) | Yes | Yes | Yes | Yes | No | No |
| Optical discs |
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General
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Optical media types
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Standards
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See also
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Different bit depth/sampling rate/channel combinations can be used on a single disc. For instance, a DVD-Audio disc may contain a 96 kHz/24-bit 5.1-channel audio track as well as a 192 kHz/24-bit stereo audio track. Also, the channels of a track can be split into two groups stored at different resolutions. For example, the front speakers could be 96/24, while the surrounds are 48/20.
Audio is stored on the disc in Linear PCM format, which is either uncompressed or losslessly compressed with Meridian Lossless Packing. The maximum permissible total bit rate is 9.6 Megabits per second. Channel/resolution combinations that would exceed this need to be compressed. In uncompressed modes, it is possible to get up to 96/16 or 48/24 in 5.1, and 192/24 in stereo. To store 5.1 tracks in 88.2/20, 88.2/24, 96/20 or 96/24 MLP encoding is mandatory.
The LFE channel is actually full range, and can be recorded at the same resolution as the other channels. This permits it to be used instead as an extra main channel, for example as a "height" speaker above the listening position; this has been done on some releases. Such usage is non-standard, and will often require special set-up by the end-user.
If no native stereo audio exists on the disc, the DVD-Audio player may be able to downmix the 5.1-channel audio to two-channel stereo audio if the listener does not have a surround sound setup (provided that the coefficients were set in the stream at authoring). Downmixing can only be done to two-channel stereo, not to other configurations, such as 4.0 quad. DVD-Audio may also feature menus, text subtitles, still images and video, plus in high end authoring systems it is also possible to link directly into a Video_TS folder that might contain video tracks, as well as PCM stereo and other "bonus" features.
Read more about this topic: DVD-Audio