Lossless Compressed Audio Format
WAV file format
The WAV format is one of the most widely used uncompressed formats for audiofiles. It stands for Waveform Audio format and was introduced in 1991 byMicrosoft and IBM. The audio container follows an uncompressed technique andis majorly used to store sound recordings in CDs.Although the format is not that popular in the present time, it is stillextensively used in the recording. The size of an uncompressed file is usuallymore since it follows a standard 14-bit encoding. Though, we can stillcompress a WAV file by following a lossless compression technique. Ideally,the size of a one-minute uncompressed WAV file can be around 10 MB.
WMA Lossless File
WMA stands for Windows Media Audio and has been developed by Microsoft.Ideally, WMA can be both lossy and lossless. The lossless WMA compressionmight not compress files as well as FLAC or ALAC, but it is recommended forits DRM support. Also, it is mostly used by native Windows users. It is apropriety compression technique and thus is not recommended for data transferor distribution.
MP3 File Format
MP3 is certainly the most popular audio format that is accepted by everyleading platform and device. It stands for MPEG-1 Audio Layer 3 and was firstintroduced by the Moving Picture Experts Group in 1993. The compressiontechnique gets rid of all the sound that is not audible to human ears or noiseand then focus on the actual data. This can reduce the size of the audio fileby 75 to 90% as compared to the original size. It is known as a universalmusic extension as the open format is used in almost every media-supportingdevice.
WMA Lossy File
Ever since the release of WMA format by Microsoft in 1999, it has gone throughseveral changes. The format can follow both lossy as well as losslesscompression techniques. It can drastically reduce the size of an audio filewhile retaining most of the data. Though, it is a propriety format, owned byMicrosoft. While the output is better than MP3, it didn’t gain popularity asit wasn’t open-source.
Lossless Compressed Audio Formats
These compression techniques are recommended to maintain a balance between thequality of music and the size of audio files. While the size would be lesserthan the original file, the quality will be maintained.
Lossy Compressed Audio Formats
This is a lossy technique, in which the size as well as the quality of theaudio would be reduced. Therefore, the original sound of the music might bealtered. The formats are mostly used for data transfer and streaming.Audio files | WAV | AIFF | PCM | FLAC | ALAC —|—|—|—|—|— Type | Uncompressed | Uncompressed | Uncompressed | Lossless Compressed |Lossless Compressed Extensions | .wav; .wave | .aiff; .aif; .aifc | .pcm; .aiff; .au; .wav; .l16 |.flac | .m4a; .caf Open Source | Partially | Partially | Yes | Yes | Partially Size Reduction | No | No | No | Up to 60% | Up to 60% Popularity | Medium | Low | High | Medium | High Audio files | WMA | MP3 | OGG | AAC | WMA (lossy) —|—|—|—|—|— Type | Lossless Compressed | Lossy Compressed | Lossy Compressed | LossyCompressed | Lossy Compressed Extensions | .wma; .wmv | .mp3 | .ogg; .oga; .mogg | .aac; .m4a; .3gp; .m4r |.wma; .wmv Open Source | No | Yes | Yes | Partially | No Size Reduction | Up to 60% | Up to 90% | Up to 90% | Up to 90% | Up to 90% Popularity | High | Most popular | Low | High | High * * *
What Is an Audio File Format?
The audio file format is a file format for storing digital audio on a computersystem like PC, mobile phone, etc. Audio information are stored as bits in thefile and can be called as bit layout.These bit layout can be uncompressed, or compressed using lossless or lossyencoding.
Audio File Formats and Sound Quality
Audio file types (From: sguru.org)Not all audio file formats are equal. Sample rate and bit depth determine theresolution, the frequency range and the dynamic range of the audio. Thestandard for CD quality audio is a sample rate of 44.1kHz, and a bit depth of16-bit.Anything below this and your audio is not considered High-Definition (HD) orHigh-Resolution. Many audio file formats use settings lower than whatqualifies as HD. The reasons are explained in the following sections.> All the music you listen to, should at the very least, have a sampling rate> of 44.1kHz (44100Hz). This rate captures frequencies up to 22050Hz, just> above the limit of human hearing (~20kHz).
Lossless Compressed Audio Format
With lossless encoding or lossless compression, you get the best of bothworlds. Lossless files are compressed, reducing the file size, and making themeasier to store and distribute.On playback, they can be decoded to the original uncompressed state, with nodegradation of the signal.Think of it as a ZIP file. When you zip your documents, it becomes compressedand the file size is reduced. When you “unzip” or decode them, your originaldocuments is recreated with nothing changed.Representation of lossless compression (From: retromanufacturing.com)How do lossless compression work?Lossless compression seems like magic. How do you throw away data but yetrecreate them back in a an exact way? Lossy compression throws away data tooand they are unable to recreate the original copy.Turns out lossless compression throws away data in a smart manner which allowsthe original copy to be recreated. This is done by identifying patterns andrepresenting the data in a shorter manner.There are complex statistical analyses been done to identify patterns forcompression but we have a simple example below to demonstrate how to throwaway data smartly.Bits for Master Studio Track:1100011110000000A lossless encoder can drop all the 0 and replace it with a symbol that takesup smaller space, thus, reducing file size:11___1111_______When the decoder receives the above bits, it will replace the symbol with the0 again to recreate the original bits.For more info on the differences between lossless and uncompressed audio, youcan read this.Apart from being used to listen to music, lossless formats are useful forarchiving audio files. No data is lost in the compression process. Althoughyou don’t get as much size reduction as lossy compression, losslesscompression can still achieve an impressive file size reduction of up to 60%.
Lossy Compressed Audio Format
Lossy encoding or lossy compression uses psychoacoustic analysis. Algorithmsdetect content deemed inaudible, because of masking (sounds not heard becauseof other sounds). It then discards this information.Representation of lossy compression (From: retromanufacturing.com)The advantage is that the file size can be drastically reduced, potentially upto 1/10th of the original size. However, it is not possible to retrieve thedata lost and restore the file to its uncompressed original format later.The downside of this is that it does affect the quality of the music. Anindicator of streaming audio quality is the bitrate, measured in kilobits persecond, kbps.Bitrate formula = Sample Rate x Bit-depth x No. of ChannelsFormat| Max bitrate —|— MP3| 320kbps AAC| 320kbps OGG| 500kbps WMA| 576kbps At bitrates of 320kbps or above, depending on the quality of your playbackequipment, it’s difficult to tell the difference between a lossy encoded file,and an uncompressed file.The lower the bitrate, the more data is being thrown away, the crappier theaudio quality.Many digital music outlets, and many streaming services such as Spotify,offer/use bitrates with a maximum of 320kbps. It reduces the quality of themusic content, directly affecting the listening experience.For some this loss of quality is not an issue and at times, not noticeable atall. For casual listening, it can be acceptable.> If you are passionate about music and/or have invested in quality playback> equipment, having the source material in the best quality possible is> paramount.With those distinctions made, let’s look at the different audio file formats.
Choose lossless compressed audio format if..
If you are an audiophile and want to store songs on the computer or digitalaudio player (DAP), you should go for lossless compressed audio format likeFLAC. Although they still take up significant space, they are a much moresuperior choice for storing high-res audio in bulk than uncompressed format.
Choose lossy compressed audio format if..
However, if you are not too critical with your listening experience and youhave limited storage space, lossy compressed audio files are the way to go.They take up less storage space on your computer hard disk and portable musicplayer. They take up less bandwidth, so they transfer faster on the internet,and when using wireless technology.