Audio file format
Encyclopedia
An audio file format is a file format
for storing digital audio
data on a computer
system. This data can be stored uncompressed, or compressed to reduce the file size. It can be a raw bitstream
, but it is usually a container format or an audio data format with defined storage layer.
and an audio codec
. A codec performs the encoding and decoding of the raw audio data while the data itself is stored in a file with a specific audio file format. Although most audio file formats support only one type of audio data (created with an audio coder
), a multimedia container format (as Matroska
or AVI
) may support multiple types of audio and video data.
There are three major groups of audio file formats:
or in a .aiff file on Mac OS
. The AIFF format is based on the Interchange File Format
(IFF). The WAV format is based on the Resource Interchange File Format (RIFF), which is similar to IFF. WAV and AIFF are flexible file formats designed to store more or less any combination of sampling rates or bitrates. This makes them suitable file formats for storing and archiving an original recording.
BWF (Broadcast Wave Format) is a standard audio format created by the European Broadcasting Union
as a successor to WAV. BWF allows metadata
to be stored in the file. See European Broadcasting Union: Specification of the Broadcast Wave Format (EBU Technical document 3285, July 1997). This is the primary recording format used in many professional audio workstations in the television and film industry. BWF files include a standardized timestamp
reference which allows for easy synchronization with a separate picture element. Stand-alone, file based, multi-track recorders from Sound Devices, Zaxcom, HHB USA, Fostex
, and Aaton all use BWF as their preferred format.
The .cda (Compact Disk Audio Track) is a small file that serves as a shortcut to the audio data for a track on a music CD. It does not contain audio data and is therefore not considered to be a proper audio file format.
Uncompressed audio formats encode both sound and silence with the same number of bits per unit of time. Encoding an uncompressed minute of absolute silence produces a file of the same size as encoding an uncompressed minute of music. In a lossless compressed format, however, the music would occupy a smaller portion of the file and the silence would take up almost no space at all.
Lossless compression formats enable the original uncompressed data to be recreated exactly. They include the common FLAC
, WavPack
, Monkey's Audio
, ALAC
(Apple Lossless). They provide a compression ratio of about 2:1 (i.e. their files take up half the space of the originals). Development in lossless compression formats aims to reduce processing time while maintaining a good compression ratio.
, to remove data with minimal reduction in the quality of reproduction. For many everyday listening situations, the loss in data (and thus quality) is imperceptible. The popular MP3 format is probably the best-known example, but the AAC format found on the iTunes Music Store is also common. Most formats offer a range of degrees of compression, generally measured in bit rate
. The lower the rate, the smaller the file and the more significant the quality loss.
File format
A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...
for storing digital audio
Digital audio
Digital audio is sound reproduction using pulse-code modulation and digital signals. Digital audio systems include analog-to-digital conversion , digital-to-analog conversion , digital storage, processing and transmission components...
data on a computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
system. This data can be stored uncompressed, or compressed to reduce the file size. It can be a raw bitstream
Bitstream
A bitstream or bit stream is a time series of bits.A bytestream is a series of bytes, typically of 8 bits each, and can be regarded as a special case of a bitstream....
, but it is usually a container format or an audio data format with defined storage layer.
Types of formats
It is important to distinguish between a file formatFile format
A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...
and an audio codec
Audio codec
All codecs are devices or computer programs capable of coding or decoding a digital data stream or signal.The term audio codec has two meanings depending on the context:...
. A codec performs the encoding and decoding of the raw audio data while the data itself is stored in a file with a specific audio file format. Although most audio file formats support only one type of audio data (created with an audio coder
Audio codec
All codecs are devices or computer programs capable of coding or decoding a digital data stream or signal.The term audio codec has two meanings depending on the context:...
), a multimedia container format (as Matroska
Matroska
The Matroska Multimedia Container is an open standard free container format, a file format that can hold an unlimited number of video, audio, picture or subtitle tracks in one file. It is intended to serve as a universal format for storing common multimedia content, like movies or TV shows...
or AVI
Audio Video Interleave
Audio Video Interleave , known by its acronym AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology. AVI files can contain both audio and video data in a file container that allows synchronous audio-with-video playback...
) may support multiple types of audio and video data.
There are three major groups of audio file formats:
- Uncompressed audio formats, such as WAVWAVWaveform Audio File Format , is a Microsoft and IBM audio file format standard for storing an audio bitstream on PCs...
, AIFFAIFFAudio Interchange File Format is an audio file format standard used for storing sound data for personal computers and other electronic audio devices...
, AUAu file formatThe Au file format is a simple audio file format introduced by Sun Microsystems. The format was common on NeXT systems and on early Web pages. Originally it was headerless, being simply 8-bit µ-law-encoded data at an 8000 Hz sample rate. Hardware from other vendors often used sample rates as...
or rawRaw audio formatRAW Audio format or just RAW Audio is a computer format for storing uncompressed audio in raw form. Comparable to WAV or AIFF in size, RAW Audio file does not include any header information . Data can be written in PCM, IEEE 754 or ASCII.-Extensions:The most typical extension is .raw or .pcm...
header-less PCM; - Formats with losslessLossless data compressionLossless data compression is a class of data compression algorithms that allows the exact original data to be reconstructed from the compressed data. The term lossless is in contrast to lossy data compression, which only allows an approximation of the original data to be reconstructed, in exchange...
compression, such as FLAC, Monkey's AudioMonkey's AudioMonkey's Audio is a file format for audio data compression. Being a lossless format, Monkey's Audio does not discard data during the process of encoding, unlike lossy compression methods such as AAC, MP3, Vorbis and Musepack....
(filename extensionFilename extensionA filename extension is a suffix to the name of a computer file applied to indicate the encoding of its contents or usage....
APE), WavPackWavPackWavPack is a free, open source lossless audio compression format developed by David Bryant.-Features:WavPack compression can compress 8-, 16-, 24-, and 32-bit fixed-point, and 32-bit floating point audio files in the .WAV file format. It also supports surround sound streams and high frequency...
(filename extensionFilename extensionA filename extension is a suffix to the name of a computer file applied to indicate the encoding of its contents or usage....
WV), TTATTA (codec)True Audio is a free software, real-time lossless audio codec, based on adaptive prognostic filters.Also, .tta is the generic extension to filenames of audio files created by True Audio codec.- Codec overview :...
, ATRACATRACAdaptive Transform Acoustic Coding is a family of proprietary audio compression algorithms developed by Sony. MiniDisc was the first commercial product to incorporate ATRAC in 1992. ATRAC allowed a relatively small disc like MiniDisc to have the same running time as CD while storing audio...
Advanced Lossless, Apple LosslessApple LosslessApple Lossless Apple Lossless Apple Lossless (also known as ALAC (Apple Lossless Audio Codec), or ALE (Apple Lossless Encoder) is an audio codec developed by Apple Inc. for lossless data compression of digital music. After initially being proprietary for many years, in late 2011 Apple open sourced...
(filename extensionFilename extensionA filename extension is a suffix to the name of a computer file applied to indicate the encoding of its contents or usage....
m4a), MPEG-4 SLSMPEG-4 SLSMPEG-4 SLS, or MPEG-4 Scalable to Lossless as per ISO/IEC 14496-3:2005/Amd 3:2006 , is an extension to the MPEG-4 Part 3 standard to allow lossless audio compression scalable to lossy MPEG-4 General Audio coding methods...
, MPEG-4 ALS, MPEG-4 DST, Windows Media Audio Lossless (WMA Lossless), and ShortenShortenShorten is a file format used for compressing audio data. It is a form of data compression of files and is used to losslessly compress CD-quality audio files . Shorten is no longer developed and more recent lossless audio codecs such as FLAC, Monkey's Audio , TTA, and WavPack have become more...
(SHN). - Formats with lossyLossy data compressionIn information technology, "lossy" compression is a data encoding method that compresses data by discarding some of it. The procedure aims to minimize the amount of data that need to be held, handled, and/or transmitted by a computer...
compression, such as MP3MP3MPEG-1 or MPEG-2 Audio Layer III, more commonly referred to as MP3, is a patented digital audio encoding format using a form of lossy data compression...
, VorbisVorbisVorbis is a free software / open source project headed by the Xiph.Org Foundation . The project produces an audio format specification and software implementation for lossy audio compression...
, MusepackMusepackMusepack or MPC is an open source lossy audio codec, specifically optimized for transparent compression of stereo audio at bitrates of 160–180 kbit/s...
, AACAdvanced Audio CodingAdvanced Audio Coding is a standardized, lossy compression and encoding scheme for digital audio. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates....
, ATRACATRACAdaptive Transform Acoustic Coding is a family of proprietary audio compression algorithms developed by Sony. MiniDisc was the first commercial product to incorporate ATRAC in 1992. ATRAC allowed a relatively small disc like MiniDisc to have the same running time as CD while storing audio...
and Windows Media Audio Lossy (WMA lossy)).
Uncompressed audio formats
There is one major uncompressed audio format, PCM, which is usually stored in a .wav file on WindowsMicrosoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
or in a .aiff file on Mac OS
Mac OS
Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface...
. The AIFF format is based on the Interchange File Format
Interchange File Format
Interchange File Format , is a generic container file format originally introduced by the Electronic Arts company in 1985 in order to ease transfer of data between software produced by different companies....
(IFF). The WAV format is based on the Resource Interchange File Format (RIFF), which is similar to IFF. WAV and AIFF are flexible file formats designed to store more or less any combination of sampling rates or bitrates. This makes them suitable file formats for storing and archiving an original recording.
BWF (Broadcast Wave Format) is a standard audio format created by the European Broadcasting Union
European Broadcasting Union
The European Broadcasting Union is a confederation of 74 broadcasting organisations from 56 countries, and 49 associate broadcasters from a further 25...
as a successor to WAV. BWF allows metadata
Metadata
The term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...
to be stored in the file. See European Broadcasting Union: Specification of the Broadcast Wave Format (EBU Technical document 3285, July 1997). This is the primary recording format used in many professional audio workstations in the television and film industry. BWF files include a standardized timestamp
Timestamp
A timestamp is a sequence of characters, denoting the date or time at which a certain event occurred. A timestamp is the time at which an event is recorded by a computer, not the time of the event itself...
reference which allows for easy synchronization with a separate picture element. Stand-alone, file based, multi-track recorders from Sound Devices, Zaxcom, HHB USA, Fostex
Fostex
Fostex is a Japanese manufacturer that is one of the largest transducer and OEM speaker makers in the world, founded in July 1973 by Foster Electric Co. Ltd.-Company history:Fostex , founded in July 1973 by Foster Electric Co...
, and Aaton all use BWF as their preferred format.
The .cda (Compact Disk Audio Track) is a small file that serves as a shortcut to the audio data for a track on a music CD. It does not contain audio data and is therefore not considered to be a proper audio file format.
Lossless compressed audio formats
A lossless compressed format stores data in less space by eliminating unnecessary data.Uncompressed audio formats encode both sound and silence with the same number of bits per unit of time. Encoding an uncompressed minute of absolute silence produces a file of the same size as encoding an uncompressed minute of music. In a lossless compressed format, however, the music would occupy a smaller portion of the file and the silence would take up almost no space at all.
Lossless compression formats enable the original uncompressed data to be recreated exactly. They include the common FLAC
FLAC
FLAC is a codec which allows digital audio to be losslessly compressed such that file size is reduced without any information being lost...
, WavPack
WavPack
WavPack is a free, open source lossless audio compression format developed by David Bryant.-Features:WavPack compression can compress 8-, 16-, 24-, and 32-bit fixed-point, and 32-bit floating point audio files in the .WAV file format. It also supports surround sound streams and high frequency...
, Monkey's Audio
Monkey's Audio
Monkey's Audio is a file format for audio data compression. Being a lossless format, Monkey's Audio does not discard data during the process of encoding, unlike lossy compression methods such as AAC, MP3, Vorbis and Musepack....
, ALAC
Apple Lossless
Apple Lossless Apple Lossless Apple Lossless (also known as ALAC (Apple Lossless Audio Codec), or ALE (Apple Lossless Encoder) is an audio codec developed by Apple Inc. for lossless data compression of digital music. After initially being proprietary for many years, in late 2011 Apple open sourced...
(Apple Lossless). They provide a compression ratio of about 2:1 (i.e. their files take up half the space of the originals). Development in lossless compression formats aims to reduce processing time while maintaining a good compression ratio.
Lossy compressed audio formats
Lossy compression enables even greater reductions in file size by removing some of the data. Lossy compression typically achieves far greater compression but somewhat reduced quality than lossless compression by simplifying the complexities of the data. A variety of techniques are used, mainly by exploiting psychoacousticsPsychoacoustics
Psychoacoustics is the scientific study of sound perception. More specifically, it is the branch of science studying the psychological and physiological responses associated with sound...
, to remove data with minimal reduction in the quality of reproduction. For many everyday listening situations, the loss in data (and thus quality) is imperceptible. The popular MP3 format is probably the best-known example, but the AAC format found on the iTunes Music Store is also common. Most formats offer a range of degrees of compression, generally measured in bit rate
Bit rate
In telecommunications and computing, bit rate is the number of bits that are conveyed or processed per unit of time....
. The lower the rate, the smaller the file and the more significant the quality loss.
List of formats
- 3gp3GP3GP is a multimedia container format defined by the Third Generation Partnership Project for 3G UMTS multimedia services. It is used on 3G mobile phones but can also be played on some 2G and 4G phones....
- multimedia container format can contain proprietary formats as AMR, AMR-WBAMR-WBAdaptive Multi-Rate Wideband is a patented speech coding standard developed based on Adaptive Multi-Rate encoding, using similar methodology as Algebraic Code Excited Linear Prediction...
or AMR-WB+AMR-WB+Extended Adaptive Multi-Rate – Wideband is an audio codec that extends AMR-WB. It adds support for stereo signals and higher sampling rates. Another main improvement is the use of transform coding additionally to ACELP. This greatly improves the generic audio coding...
, but also some open formats - actACT (audio format)ACT is a lossy ADPCM 8 kbit/s compressed audio format recorded by most Chinese MP3 and MP4 players with a recording function, and voice recorders....
- ACT is a lossy ADPCM 8 kbit/s compressed audio format recorded by most Chinese MP3 and MP4 players with a recording function, and voice recorders - AIFFAIFFAudio Interchange File Format is an audio file format standard used for storing sound data for personal computers and other electronic audio devices...
– standard audio file format used by Apple. It could be considered the Apple equivalent of wavWAVWaveform Audio File Format , is a Microsoft and IBM audio file format standard for storing an audio bitstream on PCs...
. - aacAdvanced Audio CodingAdvanced Audio Coding is a standardized, lossy compression and encoding scheme for digital audio. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates....
– the Advanced Audio Coding format is based on the MPEG2 and MPEG4 standards. aac files are usually ADTS or ADIFAdvanced Audio CodingAdvanced Audio Coding is a standardized, lossy compression and encoding scheme for digital audio. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates....
containers. - ALACApple LosslessApple Lossless Apple Lossless Apple Lossless (also known as ALAC (Apple Lossless Audio Codec), or ALE (Apple Lossless Encoder) is an audio codec developed by Apple Inc. for lossless data compression of digital music. After initially being proprietary for many years, in late 2011 Apple open sourced...
- Apple Lossless compression, a lossless compression format from Apple. - amrAdaptive Multi-RateThe Adaptive Multi-Rate audio codec is a patented audio data compression scheme optimized for speech coding. AMR was adopted as the standard speech codec by 3GPP in October 1999 and is now widely used in GSM and UMTS...
- AMR-NB audio, used primarily for speech. - atracATRACAdaptive Transform Acoustic Coding is a family of proprietary audio compression algorithms developed by Sony. MiniDisc was the first commercial product to incorporate ATRAC in 1992. ATRAC allowed a relatively small disc like MiniDisc to have the same running time as CD while storing audio...
(.wav) – the older style Sony ATRAC format. It always has a .wav file extension. To open these files, install the ATRAC3 drivers. - AuAu file formatThe Au file format is a simple audio file format introduced by Sun Microsystems. The format was common on NeXT systems and on early Web pages. Originally it was headerless, being simply 8-bit µ-law-encoded data at an 8000 Hz sample rate. Hardware from other vendors often used sample rates as...
– the standard audio file format used by SunSun MicrosystemsSun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
, UnixUnixUnix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
and JavaJava (Sun)Java refers to several computer software products and specifications from Sun Microsystems, a subsidiary of Oracle Corporation, that together provide a system for developing application software and deploying it in a cross-platform environment...
. The audio in au files can be PCMPulse-code modulationPulse-code modulation is a method used to digitally represent sampled analog signals. It is the standard form for digital audio in computers and various Blu-ray, Compact Disc and DVD formats, as well as other uses such as digital telephone systems...
or compressed with the μ-law, a-law or G729 codecs. - awb - AMR-WB audio, used primarily for speech, same as the ITU-TITU-TThe ITU Telecommunication Standardization Sector is one of the three sectors of the International Telecommunication Union ; it coordinates standards for telecommunications....
's G.722.2 specification. - dct – A variable codec format designed for dictation. It has dictation header information and can be encrypted (as may be required by medical confidentiality laws). A proprietary format of NCH SoftwareNCH SoftwareNCH Software is a software development company founded in 1993 in Canberra, Australia. The Denver office was started in April 2008 due to the large U.S. customer base...
. - dss – Digital Speech StandardDigital Speech StandardDigital Speech Standard is a proprietary compressed digital audio file format defined by the International Voice Association, a co-operative venture by Olympus, Philips and Grundig. It was originally developed in 1994 by Grundig with the University of Nuremberg. In 1997, the digital speech...
files are an OlympusOlympus Corporationis a Japan-based manufacturer of optics and reprography products. Olympus was established on 12 October 1919, initially specializing in microscope and thermometer businesses. Its global headquarters are in Shinjuku, Tokyo, Japan, while its USA operations are based in Center Valley, Pennsylvania,...
proprietary format. It is a fairly old and poor codec. Gsm or mp3 are generally preferred where the recorder allows. It allows additional data to be held in the file header. - dvf – a SonySony, commonly referred to as Sony, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan and the world's fifth largest media conglomerate measured by revenues....
proprietary format for compressed voice files; commonly used by Sony dictation recorders. - flacFLACFLAC is a codec which allows digital audio to be losslessly compressed such that file size is reduced without any information being lost...
– File format for the Free Lossless Audio Codec, a lossless compression codec. - gsm – designed for telephony use in Europe, gsm is a very practical format for telephone quality voice. It makes a good compromise between file size and quality. Note that wav files can also be encoded with the gsm codec.
- iklaxIklaxiKlax is a multitrack and interactive audio format which was developed in France by iKlax Media and the LaBRI through a project started in 2006...
– An iKlax Media proprietary format, the iKlax format is a multi-track digital audio format allowing various actions on musical data, for instance on mixing and volumes arrangements. - IVS – A proprietary version with Digital Rights ManagementDigital rights managementDigital rights management is a class of access control technologies that are used by hardware manufacturers, publishers, copyright holders and individuals with the intent to limit the use of digital content and devices after sale. DRM is any technology that inhibits uses of digital content that...
developed by 3D Solar UK Ltd for use in music downloaded from their Tronme Music Store and interactive music and video player. - m4pM4PThe term M4P refers to an approach in aid and development known as 'making markets work for the poor'. The approach utilises systems analysis as a means of diagnosing and addressing the constraints that face poor and disadvantages households and communities in accessing goods and services...
– A proprietary version of AAC in MP4 with Digital Rights ManagementDigital rights managementDigital rights management is a class of access control technologies that are used by hardware manufacturers, publishers, copyright holders and individuals with the intent to limit the use of digital content and devices after sale. DRM is any technology that inhibits uses of digital content that...
developed by Apple for use in music downloaded from their iTunesITunesiTunes is a media player computer program, used for playing, downloading, and organizing digital music and video files on desktop computers. It can also manage contents on iPod, iPhone, iPod Touch and iPad....
Music Store. - mmf - a Samsung audio format that is used in ringtones.
- mp3 - MPEG Layer III Audio. Is the most common sound file format used today.
- mpcMusepackMusepack or MPC is an open source lossy audio codec, specifically optimized for transparent compression of stereo audio at bitrates of 160–180 kbit/s...
- Musepack or MPC (formerly known as MPEGplus, MPEG+ or MP+) is an open source lossy audio codec, specifically optimized for transparentTransparency (data compression)In data compression or psychoacoustics, transparency is the ideal result of lossy data compression. If a lossy compressed result is perceptually indistinguishable from the uncompressed input, then the compression can be declared to be transparent...
compression of stereo audio at bitrates of 160–180 kbit/s. - msv – a SonySony, commonly referred to as Sony, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan and the world's fifth largest media conglomerate measured by revenues....
proprietary format for Memory Stick compressed voice files. - mxp4 – a Musinaut proprietary format allowing play of different versions (or skins) of the same song. It allows various interactivity scenarios between the artist and the end user.
- oggOggOgg is a free, open container format maintained by the Xiph.Org Foundation. The creators of the Ogg format state that it is unrestricted by software patents and is designed to provide for efficient streaming and manipulation of high quality digital multimedia.The Ogg container format can multiplex...
– a free, open source container format supporting a variety of formats, the most popular of which is the audio format Vorbis. Vorbis offers compression similar to MP3 but is less popular. - ra & rmRealAudioRealAudio is a proprietary audio format developed by RealNetworks and first released in April 1995. It uses a variety of audio codecs, ranging from low-bitrate formats that can be used over dialup modems, to high-fidelity formats for music. It can also be used as a streaming audio format, that is...
– a Real Audio format designed for streaming audio over the Internet. The .ra format allows files to be stored in a self-contained fashion on a computer, with all of the audio data contained inside the file itself. - ram – a text file that contains a link to the Internet address where the Real Audio file is stored. The .ram file contains no audio data itself.
- rawRaw audio formatRAW Audio format or just RAW Audio is a computer format for storing uncompressed audio in raw form. Comparable to WAV or AIFF in size, RAW Audio file does not include any header information . Data can be written in PCM, IEEE 754 or ASCII.-Extensions:The most typical extension is .raw or .pcm...
– a raw file can contain audio in any format but is usually used with PCM audio data. It is rarely used except for technical tests. - TTATTA (codec)True Audio is a free software, real-time lossless audio codec, based on adaptive prognostic filters.Also, .tta is the generic extension to filenames of audio files created by True Audio codec.- Codec overview :...
- The True Audio, real-time lossless audio codec. - vox – the vox format most commonly uses the Dialogic ADPCM (Adaptive Differential Pulse Code Modulation) codec. Similar to other ADPCM formats, it compresses to 4-bits. Vox format files are similar to wave files except that the vox files contain no information about the file itself so the codec sample rate and number of channels must first be specified in order to play a vox file.
- wavWAVWaveform Audio File Format , is a Microsoft and IBM audio file format standard for storing an audio bitstream on PCs...
– standard audio file container format used mainly in WindowsMicrosoft WindowsMicrosoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
PCs. Commonly used for storing uncompressed (PCM), CD-quality sound files, which means that they can be large in size—around 10 MB per minute. Wave files can also contain data encoded with a variety of (lossy) codecs to reduce the file size (for example the GSM or MP3 formats). Wav files use a RIFF structure. - wmaWindows Media AudioWindows Media Audio is an audio data compression technology developed by Microsoft. The name can be used to refer to its audio file format or its audio codecs. It is a proprietary technology that forms part of the Windows Media framework. WMA consists of four distinct codecs...
– the popular Windows Media Audio format owned by MicrosoftMicrosoftMicrosoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
. Designed with Digital Rights ManagementDigital rights managementDigital rights management is a class of access control technologies that are used by hardware manufacturers, publishers, copyright holders and individuals with the intent to limit the use of digital content and devices after sale. DRM is any technology that inhibits uses of digital content that...
(DRM) abilities for copy protection.
See also
- Red Book (audio CD standard)Red Book (audio CD standard)Red Book is the standard for audio CDs . It is named after one of the Rainbow Books, a series of books that contain the technical specifications for all CD and CD-ROM formats.The first edition of the Red Book was released in 1980 by Philips and Sony; it was adopted by the Digital Audio Disc...
- Container format (digital) definition and article
- Comparison of container formatsComparison of container formatsThis table compares features of container formats. To see which multimedia players support which container format, look at comparison of media players.-Information:-Audio formats supported:-Video formats supported:-Caption formats supported:...
- Audio compression (data)
- Comparison of video codecsComparison of video codecsA video codec is software or a device that provides encoding and decoding which may or may not include the use of video compression and/or decompression for digital video....