Audio format
From Wikipedia, the free encyclopedia
An audio format is a medium for storing sound and music. The term is applied to both the physical recording media and the recording formats of the audio content – in computer science it is often limited to the audio file format, but its wider use usually refers to the physical method used to store the data.
Music is recorded and distributed using a variety of audio formats, some of which store additional information.
[edit] Timeline of audio format developments
| Year | Media formats | Recording formats |
|---|---|---|
| 1877 | Phonograph cylinder | Mechanical analog; "hill-and-dale" grooves, vertical stylus motion |
| 1883 | Music roll | Mechanical digital (automated musical instruments) |
| 1895 | Gramophone record | Mechanical analog; lateral grooves, horizontal stylus motion |
| 1898 | Wire recording | Analog; magnetization; no "bias" |
| 1925 | Electrical cut record | Mechanical analog; electrically cut from amplified microphone signal, lateral grooves, horizontal stylus motion, discs at 7", 10", 12", most at 78 rpm |
| 1930s | Reel-to-Reel, Magnetic Tape | Analog; magnetization; "bias" dramatically increases linearity/fidelity, tape speed at 30 ips, later 15 ips with NAB equalization; refined speeds: 7 1/2 ips, 3 3/4 ips, 1 7/8 ips |
| 1930s | Electrical transcriptions | Mechanical analog; electrically cut from amplified microphone signal, high fidelity sound, lateral or vertical grooves, horizontal or vertical stylus motion, most discs 16" at 33 1/3 rpm |
| 1948 (Commercial release) | Vinyl Record | Analog, with preemphasis and other equalization techniques (LP, RIAA); lateral grooves, horizontal stylus motion; discs at 7" (most 45 rpm), 10" and 12" (most 33 1/3 rpm) |
| 1957 | Stereophonic Vinyl Record | Analog, with preemphasis and other equalization techniques. Combination lateral/vertical stylus motion with each channel encoded 45 degrees to the vertical. |
| 1962 | 4-Track (Stereo-Pak) | Analog, 1/4 inch wide tape, 3 3/4 inches/sec, endless loop cartridge. |
| 1963 | Compact Cassette | Analog, with bias, preemphasis, 0.15 inch wide tape, 17/8 inches/sec. 1970: introduced Dolby noise reduction. |
| 1965 | 8-Track (Stereo-8) | Analog, 1/4 inch wide tape, 3 3/4 inches/sec, endless loop cartridge. |
| 1969 | Microcassette | Analog, 1/8 inch wide tape, used generally for notetaking, mostly mono, some stereo. 2.4 cm/s or 1.2 cm/s. |
| 1969 | Minicassette | Analog, 1/8 inch wide tape, used generally for notetaking, 1.2 cm/s |
| 1970 | Quadraphonic 8-Track (Quad-8) (Q8) | Analog, 1/4 inch wide tape, 3 3/4 inches/sec, 4 Channel Stereo, endless loop cartridge. |
| 1971 | Quadraphonic Vinyl Record (CD-4) (SQ Matrix) | |
| 1975 | Betamax Digital Audio | 'Dolby Stereo' cinema surround sound |
| 1976 | Elcaset | |
| 1978 | Laserdisc | |
| 1982 | Compact Disc (CD-DA) | PCM |
| 1985 | Audio Interchange File Format (AIFF) | |
| 1985 | Sound Designer (by Digidesign) | |
| 1987 | Digital Audio Tape (DAT) | |
| 1991 | MiniDisc (MD) | ATRAC |
| 1992 | Digital Compact Cassette (DCC) | |
| 1992 | WAVEform (WAV)
Dolby Digital surround cinema sound |
|
| 1993 | Digital Theatre System (DTS)
Sony Dynamic Digital Sound (SDDS) |
|
| 1995 | MP3 | |
| 1997 | DVD | Dolby Digital |
| 1997 | DTS-CD | DTS Audio |
| 1999 | DVD-Audio | |
| 1999 | Super Audio CD (SACD) | |
| 1999 | Windows Media Audio (WMA) | |
| 1999 | The True Audio Lossless Codec (TTA) | |
| 2000 | Free Lossless Audio Codec (FLAC) | |
| 2001 | Advanced audio coding (AAC) | |
| 2002 | Ogg Vorbis | |
| 2003 | DualDisc | |
| 2004 | Apple Lossless (ALE or ALAC) | |
| 2005 | HD DVD | |
| 2005 | OggPCM | |
| 2006 | Blu-Ray |
