2 Audio Formats with Lossy Compression

pcbuck April 22, 2021 0 Comments



Waveform Audio (.wav)


Waveform Audio (.wav) is a common file format. Created by Microsoft and IBM,WAV was one of the first audio file types developed for the PC. WAV files aredefined as lossless, meaning that files are large and complete; nothing hasbeen lost. Professionally recorded CDs are also a lossless audio source. Incontrast, the three audio formats listed below are lossy-redundant and non-auditory data is removed to allow for more compact storage; in essence, somedata has been lost. This process of removing data to shrink the file size iscalled compression. The three file formats below must begin with a losslessformat (such as a computer WAV file) then compress it. Most lossy formatsboast little or no detectable change in sound quality. But because eachcompressing format selects the deleteable data differently, converting onecompressed file into another lossy format will sometimes result in lowerquality audio. Again, always start with a WAV file, then compress.(Image credit: Adobe)

MPEG-1 or 2 Audio Layer 3 (.mp3)


MPEG-1 or 2 Audio Layer 3 (.mp3) is a common, compressed WAV file. MPEG-1files are about one-twelfth the size of WAV files. This is why MP3 players canaccommodate hundreds of songs on a tiny chunk of storage space.Windows Media Audio (.wma) was developed to compete with the MP3 format forWindows Media Player. Microsoft claims that the WMA files are compressed threetimes more than MP3s yet retain their original sound quality.

Other audio file types


* Musical Instrument Digital Interface (.midi) Musical Instrument Digital Interface (.midi) is commonly used for computer keyboards and other computer-based musical tools. MIDI files contain musical notes, rhythm notation and other information often needed by a composer. * Audio Interchange File (.aif, .aifc or .aiff.) Audio Interchange File (.aif, .aifc or .aiff.) was developed for the Mac computer to store audio files. * Sun Audio (.au) Sun Audio (.au) or Audio/Basic was developed by Sun Microsystems for use on UNIX systems. * Emblaze Audio (.ea) Emblaze Audio (.ea) was created by Geo and offers compression similar to MP3 formats, but its purpose is to be played with a JAVA applet-a miniature Internet program. Online greeting cards often use JAVA applet programs for motion and .ea sound files to play music.The Thing (2002) – MobyGames

1. Uncompressed Audio Formats


Uncompressed audio formats are the most accurate and genuine representation ofthe original sound waves. The sound from uncompressed files is very similar tohow it was recorded and intended to listen. Since the files do not undergo anykind of compression, there is no loss of information, which results in a high-quality audio experience and a fairly large file size. When compared to mostof the other audio formats, uncompressed audio formats offer the best audioexperience of the lot.

(b) Waveform Audio File Format (WAV)


The WAV audio file format was developed by Microsoft and IBM back in the year1991. And during that initial time, it used to be called ‘Audio forWindows’. WAV, in a nutshell, is like a container for various audio formats,because of which, it can sometimes contain compressed audio formats. However,that is rarely the case, and most of the times, the files are uncompressed andpresent in the PCM audio format.

(c) Audio Interchange File Format (AIFF)


Similar to WAV, which is developed by Microsoft and IBM, and largely intendedfor use on Windows, the AIFF format is an in-house format developed by Applefor its Mac lineup. Much like WAV for Windows, AIFF is a container for Apple,which can hold different kinds of audio formats. However, more than anything,it is a wrapper for the PCM format, specifically for the Mac.Note: Both WAV and AIFF are also compatible with Mac and Windows,respectively.

2. Audio Formats with Lossy Compression


Lossy compression is that compression which incurs a loss of data during thecompression process. And since compression is required to shrink down the filesize of an audio file, the trade-off for quality is acceptable in most use-case scenarios. Depending on how the compression is carried out, it can turnout to be either a good compression — with not much loss of data — or badcompression — that completely tampers the audio quality and introducesartifacts that alter the original audio. Since the smaller file size alsoaccompanies a loss of data and audio fidelity, lossy compression is not thepreferred choice in professional settings which demand high-quality audio.

(a) MPEG-1 Audio Layer 3 (MP3)


MP3 is a relatively older format than most other audio formats normally foundin use today. Back when it released, MP3 replaced the MIDI and WAV files thatwere widely used at that time, and slowly made its way into the mainstream.And later, got adopted as the standard format used in audio CDs and variousmusic portals. One of the main reasons for the widespread adoption of MP3 isits smaller file size, which, the format manages to achieve using a lossy datacompression algorithm that gets rid of some data (sound that is usually beyondhearing capabilities of humans). And back in the day, since a majority ofdevices did not come with massive storage space like they do today, the sizeof an audio file was a major deterrent in choosing an audio format. Eventoday, most of the devices in the market come with support for MP3 audiofiles, which speaks for its popularity and widescale adoption.

(d) Windows Media Audio (WMA) – Lossy


Going by its name, one can get an idea about the involvement of Microsoft,which apparently owns this proprietary audio format. WMA was essentiallyintroduced to address some of the issues with the compression algorithm usedin MP3, which Microsoft managed to do a good job of fixing, and bringing intolight a better audio format that dealt with a lot of compression qualityissues. However, since it was a proprietary format, it did not find muchtraction in the audio industry, and despite having fixed some of the prominentissues that MP3 had, it still failed to find its place across differentdevices and platforms currently in use. However, due to its advantages overMP3, if one has to choose between using MP3 and WMA on a Windows platform, WMAappears to be a better choice between the two formats.

3. Audio Formats with Lossless Compression


Unlike lossy compression which loses some data during the compression process,and in-turn alters the original audio quality, lossless compression, on theother hand, reduces the file size of an audio file by keeping the audioquality intact, without any loss of data. And since there is no loss of datain compression, the audio quality is not compromised, which makes theseformats a preferred choice for use in a professional environment. While thebigger file size might not be a deal-breaker for some, people with limitedstorage space on their device might need to resort using other audio formats.

(a) Free Lossless Audio Codec (FLAC)


FLAC is an open-format that has rapidly found its way to becoming one of themost popular formats for the high-quality audio experience. It is prettysimilar to MP3 in some ways, but lossless, which is why, unlike MP3 it doesnot undergo any loss of data during compression and offers an actualrepresentation of the original audio, much like a CD-level quality in smallerfile size. Over the years, different platforms and devices have startedsupporting the FLAC format, which has in-turn, evolved FLAC as an alternativeto the very popular MP3 format.

(b) Apple Lossless Audio Codec (ALAC)


Similar to FLAC, the ALAC format also offers an original audio qualityexperience, but in comparatively smaller file size. The reduction of the filesize, however, does not involve any loss of data during the compressionprocess. Despite its similarities with FLAC, ALAC does not share the samepopularity and range of supported platforms and devices since it is designedto only work with the Apple products. Conversely, users with an Apple devicecannot natively use the FLAC format. And therefore, have to resort with itsequivalent for Apple devices, ALAC.

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