Dolby Surround At A Glance
| Decoder | Encoder | Year | Description | Channels |
|---|---|---|---|---|
| Dolby Stereo | 1975 | Cinema use with optical technology. Uses Dolby A for noise reduction. Upmix stereo to Surround 4.0 | FL FR with C and MonoSurround matrixed | |
| Dolby Surround | Dolby Surround | 1982 | First Home use. Analog. Upmix stereo to Surround 3.0 | FL FR and MonoSurround matrixed |
| Dolby Stereo SR | 1986 | Cinema use. Uses Dolby SR for noise reduction. | FL FR with C and MonoSurround matrixed | |
| Dolby Pro Logic | 1987 | Improved Dolby Surround. Upmix Stereo to Surround 4.0. | FL FR with C and MonoSurround matrixed | |
| Dolby Digital | AC3 | 1992 Film 1995 Laser Disc |
Discrete channel encoder/decoder. Pro Logic Decoder can be used for downmixed stereo inputs. | FL FR C SL SR SUB |
| Dolby Digital EX/Dolby Digital Surround EX | 1999 | non-discrete 6.1 or 7.1 (5.1 with Center Rear matrixed onto SL & SR) | FL FR C SL SR (with matrixed RearMono) SUB | |
| Dolby Pro Logic II | 2000 | Improved Dolby Pro Logic. Upmix Stereo to Surround 5.1 in either Movie, Music, or Game mode. | FL FR C SL SR SUB | |
| Dolby Pro Logic IIx | 2002 | Upmix Stereo or Surround 5.1 to 6.1 or 7.1 in either Movie, Music, or Game mode. | FL FR C SL SR SUB Left Back and Right Back | |
| Dolby Digital Plus | Dolby Media Encoder | 2005 | Lossy compression codec; 48 kHz sampling frequency, 20-bit word length; supports data rates of 32 kbit/s – 6 Mbit/s, scalable, including 768 kbit/s – 1.5 Mbit/s on high-definition optical discs, typically, and 256 kbit/s for broadcast and online. 1.0- to 7.1-channel support for current media applications; extensible to 16 channels; discrete. Backward compatibile with Dolby Digital through S/PDIF connection up to 640 kbit/s. Supports Dolby Metadata. | FL FR C SL SR SUB Left Back and Right Back |
| Dolby TrueHD | Dolby Media Encoder | 2005 | Lossless compression codec; supports 44.1 kHz to 192 kHz sampling frequency up to 24-bit word length; supports variable data rate up to 18 Mbit/s; maximum channel support is 16 channels as presently deployed. Higher bitrate than Dolby Digital Plus. 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; and two- to six-channel support up to 192 kHz/24-bit maximum bit rate up to the maximum of 18 Mbit/s. | |
| Dolby Pro Logic IIz | 2009 | Upmix Stereo or Surround 5.1/7.1 to 7.1 Height or 9.1 with the addition of front height channels. (Based on Dolby Pro Logic IIx.) | L, C, R, Ls, Rs, Lrs (Left Back), Rrs (Right Back), LFE, Lvh and Rvh |
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