Part 2 Lossless Compressed Audio Formats
Part 2: Lossless Compressed Audio Formats
Since uncompressed files can consume a lot of space, it is recommended tocompress these sound files for storing. In the lossless compression technique,the original data is retained while shrinking the file size. This would dependon the compression algorithm that is used. Ideally, lossless techniques canmake files 2 to 5 times smaller in size while still retaining the originaldata.
Part 3: Lossy Compressed Audio Formats
If you don’t want your music files to take a lot of space, then you shouldknow about these file extensions. They follow a lossy compression techniqueand thus the original data quality is compromised. Therefore, the music filemight not sound just like the original audio. Though, it will also reduce thesize of the file drastically.
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.
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 lossless audio?
In its purest form, lossless refers to uncompressed music. “Lossless audio isthe unmodified output of the recording process. It’s the most accuraterepresentation of output of the recording process that exists,” says GiladTiefenbrun, CEO at hi-fi and audio equipment company Linn, which pioneeredStudio Master downloads in 2007.The Studio Master – the original recording file laboured over by the artistsand producers – perfectly captures the sound, the texture, the detail, and thespace required to express the feeling and the emotion of the originalperformance.The Studio Master – the original recording laboured over by the artists andproducers – perfectly captures the sound, the texture, the detail, and thespace required to express the feeling and the emotion of the originalperformance. Planning at high-res multi-room streaming company Bluesound.Lossless, studio-quality audio formats include AIFF and WAV, though theresulting files are often pointlessly massive. Cue lossless compression files.The FiiO M3 player supports 24-bit/96kHz playback
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).
Uncompressed Audio Format
If your audio files are uncompressed, they are 100% bit-for-bit identical asthe producer created them in, digital copies.Uncompressed formats are created using pulse code modulation, PCM. This is thesame format used for CDs and DVDs.So if your master studio has the following bits:1100110011000000The PCM track will contain the exact same bits:1100110011000000Sampling and quantization of a signal for PCM (From: Wikipedia)Large File SizeSince the PCM is uncompressed, uncompressed files take up a huge amount ofdisc space. The only suitable portable medium to hold such files are on discssuch as CD, DVDs or even Blu-ray disc. (RIP HD DVD)
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.