WAV

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**Waveform** <tr><th style="white-space: nowrap;">File extension:</th><td>`.wav`</td></tr><tr><th style="white-space: nowrap;">MIME type:</th><td>`audio/wav audio/wave`</td></tr><tr><th style="white-space: nowrap;">Type code:</th><td>WAVE</td></tr><tr><th style="white-space: wrap;">Uniform Type Identifier:</th><td>com.microsoft.waveform-audio</td></tr><tr><th style="white-space: nowrap;">Developed by:</th><td>Microsoft & IBM</td></tr><tr><th style="white-space: nowrap;">Type of format:</th><td>audio file</td></tr><tr><th style="white-space: nowrap;">Extended from:</th><td>RIFF</td></tr>

WAV (or WAVE), short for Waveform audio format, is a Microsoft and IBM audio file format standard for storing audio on PCs. It is a variant of the RIFF bitstream format method for storing data in "chunks", and thus also close to the IFF and the AIFF format used on Macintosh computers. Both WAVs and AIFFs are compatible with Windows and Macintosh operating systems. It takes into account some differences of the Intel 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 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, 16 bits per sample. 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.

1 Popularity
2 Limitations
3 Audio CDs
4 See also
5 External links

[edit] 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 formats such as MP3, AAC, Ogg and WMA are used to store and transfer audio, since their smaller file sizes allow for faster transmission over the internet as well as lower disk space consumption. There are also more efficient lossless codecs available, such as FLAC, Shorten, Monkey's Audio, Apple Lossless, WMA Lossless, TTA, and WavPack.

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. Because of this, it continues to enjoy widespread use with a variety of software applications, often functioning as a lowest common denominator when it comes to exchanging sound files between different programs.

[edit] 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. The RF64 format specified by the European Broadcasting Union has also been created to solve this problem.

[edit] 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 that can't be understood by CD players directly. To record WAV files to an Audio CD the file headers must be stripped and the remaining PCM data written directly to the disc as individual tracks with zero padding added to match the CD's sector size.

[edit] See also

BWF, Broadcast Wave Format
RF64, An extended File Format for Audio (multichannel file format enabling file sizes to exceed 4 Gbyte)

[edit] External links

Multimedia compression formats
Video compression formats	ISO/IEC	MPEG-1 \| MPEG-2 \| MPEG-4 \| MPEG-4/AVC	ITU-T	H.261 \| H.262 \| H.263 \| H.264	Others	AVS \| Dirac \| Indeo \| MJPEG \| RealVideo \| VC-1 \| Theora \| VP6 \| VP7 \| WMV
Audio compression formats	ISO/IEC MPEG	MPEG-1 Layer III (MP3) \| MPEG-1 Layer II \| AAC \| HE-AAC	ITU-T	G.711 \| G.722 \| G.722.1 \| G.722.2 \| G.723 \| G.723.1 \| G.726 \| G.728 \| G.729 \| G.729.1 \| G.729a	Others	AC3 \| ATRAC \| FLAC \| iLBC \| Monkey's Audio \| Musepack \| RealAudio \| SHN \| Speex \| Vorbis \| WavPack \| WMA
Image compression formats	ISO/IEC/ITU-T	JPEG \| JPEG 2000 \| JPEG-LS \| JBIG \| JBIG2	--	--	Others	BMP \| GIF \| ILBM \| PCX \| PNG \| TGA \| TIFF \| WMP
Media container formats	General	3GP \| ASF \| AVI \| FLV \| Matroska \| MP4 \| MXF \| NUT \| Ogg \| Ogg Media \| QuickTime \| RealMedia	Audio only	AIFF \| AU \| WAV	--	--