Uncompressed formats.
WAV.
A wave file, is the most used uncompressed file format. This file format is a subset of Microsoft’s RIFF specification for the storage of multimedia files. A RIFF file starts out with a file header followed by a sequence of data chunks.
A WAVE file is often just a RIFF file with a single «WAVE» chunk which consists of two sub-chunks — a «fmt » chunk specifying the data format and a «data» chunk containing the actual sample data. Call this form the «Canonical form».
This file format is preferred by most of the technicians during studio recording and DJ’s. The WAV files contain more details and you can obtain more precise sound with it.
BWF.
The increasing use of computer technology and equipment in broadcasting creates a need for seamless exchange of audio material between different broadcast environments and equipment based on different computer platforms. The EBU (European Broadcast Union) has specified a file format which contains the minimum information that is considered necessary for all broadcast applications. The basic information, together with the audio data, is organized as «Broadcast Wave Format», BWF files.
The purpose of this file format is the addition of metadata to facilitate the seamless exchange of sound data between different computer platforms and applications. It specifies the format of metadata, allowing audio processing elements to identify themselves, document their activities, and supports timecode to enable synchronization with other recordings. This metadata is stored as extension chunks in a standard digital audio WAV file.
AIFF.
The Audio Interchange File Format (AIFF) provides a standard for storing sampled sounds. The format is quite flexible, allowing for the storage of monaural or multichannel sampled sounds at a variety of sample rates and sample widths.
AIFF is primarily an interchange format*, although application designers should find it flexible enough to use as a data storage format as well. If an application does choose to use a different storage format, it should be able to convert to and from the format defined in this document. This will facilitate the sharing of sound data between applications.
In addition to audio data, AIFF can include loop point data and the musical note of a sample, for use by hardware samplers and musical applications.
This format is currently widely used on Apple Macintosh computers.
* A generic container file format originally introduced by the Electronic Arts company in 1985 (in cooperation with Commorode) in order to facilitate transfer of data between software produced by different companies.
Compressed formats – Lossless formats:
FLAC.
FLAC stands for Free Lossless Audio Codec, a lossless audio format, meaning that audio is compressed in FLAC without any loss in quality. This is similar to how Zip works, except with FLAC you will get much better compression because it is designed specifically for audio, and you can play back compressed FLAC files in your player just like you would another file.
FLAC stands out as the fastest and most widely supported lossless audio codec, and the only one that at once is non-proprietary, is unencumbered by patents, has an open-source reference implementation, has a well-documented format and API, and has several other independent implementations.
WavPack.
WavPack is a completely open audio compression format providing lossless, high-quality lossy, and a hybrid compression mode. In the default lossless mode WavPack acts just like a WinZip compressor for audio files. However, unlike MP3 or WMA encoding which can affect the sound quality, not a single bit of the original information is lost, so there’s no chance of degradation. This makes lossless mode ideal for archiving audio material or any other situation where quality is paramount. The compression ratio depends on the source material, but generally is between 30 and 70%.
The hybrid mode provides all the advantages of lossless compression with an additional bonus. Instead of creating a single file, this mode creates both a relatively small, high-quality lossy file that can be used all by itself, and a «correction» file that (when combined with the lossy file) provides full lossless restoration.
MLP.
Meridian Lossless Packing is a lossless compression technique developed by Meridian Audio that eliminates the redundancy of PCM audio signals. It achieves a compression ratio of approximately 2:1, while allowing the signal to be perfectly recreated by an MLP decoder.
The DVD-Audio uses this compression, a single-side one can record about 2 hours of 6-channel audio and 24-bit/96 KHz quality or about 2 hours in 24-bit/192 KHz stereo.
This format, like other Lossless formats, does not lose quality once compressed, and its original wave can be reconstructed exactly.
APE (MONKEY’S AUDIO):
Monkey’s Audio is a file format for compressing audio information. Being a lossless compression format, Monkey’s Audio does not eliminate audio stream information.
Similar to other compression methods, the main advantage of using Monkey’s Audio is in reducing the bandwidth and storage requirements, but in the case of Monkey’s Audio, the integrity of the sound source must not be sacrificed (as is the case with the MP3). The audio sources compressed with Monkey’s Audio can be compressed to approximately (varying according to type of sounds, musical genre, presence of silences …) half of its original size.
Monkey’s Audio is suitable for distribution, playback and archiving purposes. It is usually very slow to decompress on portable audio devices, and has limited compatibility on platforms other than Windows.
Monkey’s Audio files use the .ape extension for audio, and .apl for track metadata.
ALAC:
Apple Lossless (also known as Apple Lossless Encoder, ALE, or Apple Lossless Audio Codec, ALAC) is lossless audio codec developed by Apple Computer.
Apple Lossless data is stored within an MP4 or MOV container with the filename extensions .m4a or .mov. It is not a variant of AAC, but a totally new codec. Apple iPods with a dock connector and recent firmware can play Apple Lossless encoded files. It does not utilize any DRM scheme, but by the nature of the container, it is thought that DRM can be applied to ALAC much the same way it can with other files in QuickTime containers.
Apple claims that audio files compressed with its lossless codec will use up «about half the storage space» that the uncompressed data would require.
REFERENCES:
– Weber, J.T. (2005, September 15). The WAVE File Format. Retrieved from: http://www.lightlink.com/tjweber/StripWav/WAVE.html
– EBU Technical Review. (2004, May 6). Broadcast Wave Format (BWF) User Guide. Retrieved from: https://www.aelius.com/njh/wavemetatools/doc/bwf_user_guide.pdf
– Kabal, P. (2017, September 20). Audio File Format Specifications. Retrieved from: http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/AIFF/AIFF.html
– Coalson, J. (2013, April 4.) “FLAC format”.Retrieved from: https://xiph.org/flac/format.html#stream
– WavePack “Hybrid lossless audio compression” [Web log post]. Retrieved from: http://www.wavpack.com/
– Stuart, J.T. Craven, P.G. Gerzon, M.A. Law, M.J. Wilson, R.J. (1999, June) MLP Lossless Compression. Retrieved from: https://www.meridian-audio.info/public/mlp_jap_new%5B2521%5D.pdf
– Ashland, M. (2000-2019) Monkey’s Audio “A fast and powerful lossless audio compressor”. Retrieved from: https://monkeysaudio.com/
– Apple Inc. (2019, November 29) Apple Lossless Audio Codec. Retrieved from: https://macosforge.github.io/alac/
Noise above our heads. 