WAV

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WAV (or WAVE), short for Waveform audio format, is a Microsoft and IBM audio file format standard for storing audio on personal computer. It is a variant of the RIFF bitstream format method for storing data in "chunks", and thus also close to the Interchange File Format (IFF) and the AIFF format used on Apple Macintosh computers. Both WAVs and AIFFs are compatible with Window and Macintosh operating systems. It takes into account some differences of the Intel Central processing unit (CPU) such as little-endian byte order. The RIFF format acts as a "wrapper" for various audio compression codecs. It is the main format used on Microsoft Windows systems for raw audio.

Though a WAV file can hold compressed audio, the most common WAV format contains uncompressed audio in the pulse-code modulation (PCM) format. PCM audio is the standard audio file format for CDs at 44,100 samples per second. Since PCM uses an uncompressed, lossless storage method, which keeps all the samples of an audio track, professional users or audio experts may use the WAV format for maximum audio quality. WAV audio can also be edited and manipulated with relative ease using software.

Popularity

As file sharing over the Internet has become popular, the WAV format has declined in popularity, primarily because uncompressed WAV files are quite large in size. More frequently, compressed but lossy data compression formats such as MP3, Ogg Vorbis and Advanced Audio Coding (AAC) are used to store and transfer audio, since their smaller file sizes allow for faster transfers over the Internet, and large collections of files consume only a conservative amount of disk space. There are also more efficient lossless codecs available, such as Monkey's Audio, TTA, WavPack, FLAC, Shorten, Apple Lossless and Windows Media Audio (WMA) Lossless.

The usage of the WAV format has more to do with its simplicity and simple structure, which is heavily based on the IFF file format. So it is wide spread with all kinds of software and is more or less a lowest common denominator, when it comes to exchanging sound files between different programs.

Limitations

The WAV format is limited to files that are less than 4 GiB in size, due to its use of a 32 bit unsigned integer to record the file size header (some programs limit the file size to 2 GiB). Although this is equivalent to about 6.6 hours of CD-quality audio (44.1 kHz, 16-bit stereo), it is sometimes necessary to go over this limit. The W64 format was therefore created for use in Sound Forge. Its 64-bit header allows for much longer recording times. This format can be converted using the libsndfile library.

Audio CDs

Audio CDs do not use WAV as their sound format, instead using Red Book audio. The commonality is that both audio CDs and WAV files have the audio data encoded in PCM. WAV is a data file format for computer use. If one were to transfer an audio CD bit stream to WAV files and record them onto a CD-R as a data disc (in ISO format), the CD could not be played in a player that was only designed to play audio CDs.


This article is licensed under the GNU Free Documentation License. It uses material from the article: WAV on the WIKIPEDIA

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