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ABOUT DIGITAL AUDIO FORMATS

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ABOUT DIGITAL AUDIO FORMATS

Digital Audio Formats

Today, there are several digital audio formats that are superior in quality to compact discs and are available on both physical media and the Internet. What are advanced sound lovers listening to now? Let’s find out.

Digital Audio Formats

The capabilities and quality of the CD-DA format were initially limited by the capabilities of CD as a medium. Legend has it that the standard 74-minute compact disc capacity was chosen in order to be able to record long classical pieces without splitting into two discs. And to be absolutely precise, this figure appeared thanks to Beethoven’s Ninth Symphony: it lasts exactly 74 minutes. Another default parameter was the 44.1 kHz sample rate. This figure defines the upper limit of the reproduced frequency range. For a CD that had to reproduce frequencies up to 20 kHz, this was the lowest possible carrier frequency. As a result, the only field of maneuver was the bit depth, the level of which was 16 bits. With regard to sound recording, bit depth determines its dynamic range and resolution.

The CD cannot be copied into the memory of the computer in the usual way, since we usually copy files. To save a CD-DA, you need a special program, a program that allows you to convert data recorded on an audio disc to PCM format (WAV file). A properly organized CD-DA ripping process allows you to get a completely identical digital copy on your hard drive. Audio CDs are generally saved on a computer as a large FLAC audio file (also WAV, WV, or APE) with a CUE index card or as separate tracks.

As the best digital audio format, the CD did not last that long, just over ten years. In the mid-nineties, the first format appeared that allows for better sound quality. HDCD was an improved version of CD-DA. Their difference consisted in a special recording algorithm that made it possible to save additional data on the sampling depth in a standard CD format. With an HDCD decoder, the output signal received not 16, but 20 bits, which did not give the standard of 96, but up to 120 dB of dynamic range and a very noticeable increase in recording resolution. At the same time, devices without an HDCD decoder played discs like normal CD-DAs. Interestingly, when saving such a disk on a PC in the same way,

The next leap in terms of sound quality came at the beginning of the new millennium. Two HD audio formats were introduced to the audiophile audience at once, appearing almost simultaneously. DVD-Audio, a further development of the traditional recording method and promoted by Panasonic and Toshiba. It is capable of recording 24-bit / 192 kHz in stereo mode and 24-bit / 96 kHz in multi-channel mode.

The SACD format competed with it, which, by the way, looked much less like a normal CD, although it was called “super CD”. Super Audio CD, developed by Sony, was based on the revolutionary DSD encoding algorithm. This digitizing method assumed one-bit sampling at an ultra-high frequency of 2.8224 MHz. The encoding and decoding principles of a DSD stream are much simpler than in high-bit formats and are essentially closer to the principles of analog technology. At the same time, the SACD format retains all the advantages of the advanced digital format and has output characteristics comparable to DVD-Audio in both sound quality and number of channels.

Both DVD-Audio and SACD were designed with a high level of copy protection, but inquisitive minds have already won over both formats, so if desired, the content of both disc types can be saved to a PC as images. ISO (without changing the structure and original codec) or FLAC tracks in 24-bit / 96 kHz or 24-bit / 192 kHz. Almost simultaneously with the DVD-Audio and SACD formats, another original format for publishing high-quality music was born: DAD 24/96. DAD stands for Digital Audio Disk, but it is essentially a DVD-Video with a high-quality still image and sound that can be played on any standard DVD player or PC.

Obviously, with this approach, Blu-ray media, with its HD sound formats, recorded in high quality without compression, is quite applicable for recording music in high quality. However, at the moment there are few such publications, and a special version of the BD-Audio format has every chance of not seeing the light of day, as the sale of high-quality audio material is already very active on the Internet. Anyone who does not want to convert DVD-Audio, DAD and SACD discs to the FLAC format on their own can officially buy albums already converted in 24-bit / 96 kHz or 24-bit / 192 kHz quality.

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Advantages and disadvantages of popular audio formats

Advantages and disadvantages of popular audio formats

Audio File Formats

In today’s music world, there are a large number of audio file formats that are often confusing to the unprepared user. To understand all this, to find out what they are and what they are used for, the presented review will help.

Audio formats

Types of audio formats

Today is the time when all music lovers, not to mention professional musicians and audio editors, need to understand concepts like audio file formats, bit rates, extensions, bit depth, sample rate and many others. to achieve high quality sound. Sound has gone digital, which means that it can be used for various purposes, eg for listening to evidence, for presentations, video dubbing. In fact, digital sound, like an image, is a collection of individual pixels, and the more there are, the better the sound image. This “pixelated” sound can be edited and processed.

An important role in evaluating the quality of audio formats and consequently sound quality is a parameter such as bit rate, which shows how many bits or kilobits it takes to record one second of sound. Low bit rates mean low quality sound, high bit rates mean high quality sound.

But for the storage and further use of audio in one form or another, audio formats are used – digital recordings of audio data. We can say that the format is a kind of container where the sound is stored. Virtually all audio formats can be divided into two broad categories: lossless compressed and lossy compressed.

No loss, no loss

To avoid as much as possible a decrease in sound quality during the compression of an audio file, special methods have been developed to store audio information, avoiding losses, which in fact can be compared with the file when the information is simply packed in a zip file, the size of which is noticeably smaller than the original data. Later, this data can be clearly restored on each bit. And the bitrate itself is not important for these files. These audio files are collectively called Lossless, Music As Is. These algorithms allow you to compress files two to three times. As a result, the size becomes quite large, but at the same time the original sound is preserved.

Digital audio formats

Digital Audio Formats

Now there are several formats, but a basic distinction is made between lossless and lossy formats and compressed or uncompressed formats. Lossy formats are always compressed, which means a reduction in required storage space, but at the expense of playback quality. Lossless compressed formats offer faithful playback with low memory requirements.

However, the savings are less than with lossy formats. Lossless and uncompressed formats offer true-to-original music reproduction, but require a comparatively large amount of storage space. In return, they sometimes support even higher resolutions than compressed formats.

digital audio formats

What are sample rates and bit depth?

When talking about the resolution of digital music, two numbers are often mentioned. For CD quality around 44.1 kHz and 16 bit. The first number is the sample rate of the file. Describes how often the computer or network player extracts a signal from the file and processes it. 44.1 kHz means that a certain amount of data is transmitted 44,100 times per second. This amount of data is described by the bit depth (also word depth), the second number.

At the quality described, 16 bits of data are transmitted 44,100 times per second. If you want to determine the actual amount of data per second, you need to multiply these two numbers and get 705,600 accordingly. Since this is a stereo file with 2 channels, this number should be taken twice.

With CD quality music, 1,411,200 bits per second or, for the sake of simplicity, 1,411.2 kilobits are transmitted. A good MP3 file only transmits 320 kbps, so it only contains about a third of the information on a CD. Compared to 192 kHz 24-bit files, even less.What is the difference between compressed and uncompressed formats?
Uncompressed formats like

WAV do not affect music in any way. Frequencies and information are stored exactly as they are read during encoding. Therefore, uncompressed formats require more storage space in the first place than compressed formats. However, compressed does not automatically mean lossy. Formats like Apple’s FLAC or ALAC save music losslessly as a WAV file. However, they pack existing data more neatly without removing any information, thus requiring less storage space. Normally, there should be no effects on music information.

Why aren’t MP3 files high fidelity?

The MP3 format was introduced in 1992. It was revolutionary for the time, because by encoding music in MPEG-Audio Layer III, the full name of the format, you could achieve file compression of at least 4: 1, usually even 10: 1, compared to the classic CD. . This is possible because encoding in MP3 format removes the parts of the original file that are considered the least useful.

You can never make an exact copy of a music file in MP3 format and you cannot add information that has been deleted. So there is no point in converting an MP3 back to a lossless format. The AAC format used by Apple also cuts information from the original file to save space during compression.

We speak here of lossy or in English also of “lossy”, in contrast to the formats without loss or “without loss”. Meanwhile, it doesn’t really make sense to use such formats anymore, as more storage space shouldn’t be a problem today, unlike in 1992. The sound quality of MP3s is also significantly lower than that of other formats, as only 320 kbps is transmitted here at best, usually only 192 kbps or 256 kbps.

What is metadata?

Metadata are files attached to a file that contain additional information. In the case of digital music, these typically include things like sample rate, bit depth, and file format. In the best case, information about the song title, artist, album, composer, track number, etc. is also attached to the file. Modern streaming clients display this information when they play games on their screen or in an app. Also, these hidden attachments are often responsible for how the music in memory is organized.

Audio formats

Before going through the different audio formats to identify the best ones for you, it seems right to try to make you understand what digital audio is. In short, it is nothing more than a representation of real sounds through a chain of zeros and ones. The more there is in a file, the closer the digital sound will be to what it represents.

Better audio formats

It all started with Pulse-Code Modulation (PCM), created in 1937 and characterized by two properties: the sampling frequency to measure the amplitude of the waveform and the bit depth to measure possible digital values. It is basically the faithful conversion of analog audio into a digital file in which no compression is done. The result is a very large audio file, which takes up a lot of space.

To remedy this, therefore, more or less compressed audio formats have been created that, depending on their characteristics, are divided into two different types: Lossless formats, that is, when the information contained in the final file is identical to that contained in the source file and therefore there is no loss of quality, and lossy formats, for which the information contained in the final file is less than that contained in the source file with the consequent loss of quality but in benefit of the space of necessary storage. For more details, continue reading, below you will find the different audio formats belonging to the categories in question indicated and explained.

Lossless (WAV, AIFF, FLAC and ALAC)

As I told you a few lines above, Lossless audio formats are those that are not compressed or that, despite being subjected to this type of treatment, the final quality remains practically unchanged with respect to the original audio. The main formats that belong to this category are the following: WAV, AIFF, FLACC, ALAC and APE. Let’s see its characteristics in detail.

WAV – An acronym for WAVEform audio file format, is a standard that was developed by Microsoft and IBM in 1991. It is the most popular category of apparent audio file format. It is not compressed and is essentially what you get when you rip audio from a music CD with your computer. It takes up a lot of space (1,411 kilobits of information per second of stereo music at 44,100 Hz / 16 bits), but it reproduces sounds faithfully. In terms of quality and quantity of information, it is similar to the AIFF format, which you will find explained below.
AIFF – Short for Audio Interchange File Format, it belongs mainly to the Mac world, it was developed by Apple based on the Electronic Arts Interchange File Format and is particularly suitable for audiophiles and music recorders. It basically has the same characteristics as the WAV format mentioned above, so it is not compressed, so it takes up a lot of space (1,411 Kilobits of information per second of stereo music at 44,100 Hz / 16 bits) and is capable of reproducing sounds with a lot of fidelity.

FLAC: is the abbreviation for Free Lossless Audio Codec. It is an open source codec that is often used to store music CDs on the computer without loss of quality and is compatible with most programs and devices. Compared to the formats that I have already told you about, it has a minimal degree of compression, but most people cannot perceive significant differences compared to a WAV or AIFF file.
ALAC – Short for Apple Lossless Audio Codec, is essentially Apple’s worldwide counterpart to the earlier FLAC format. The quality is good on average but the format is not as efficient as the FLAC in terms of weight. Then keep in mind the fact that not all gamers support it, so unless you have uniquely and exclusively Apple devices, it may not be the best solution to opt for.

Other important but less common audio formats that always belong to the Lossless calorie are Monkey’s Audio (APE) and OptimFROG (OFR). Its characteristics are more or less similar to those of the FLAC and ALAC formats.

Lossy (MP3, AAC, WMA, and Ogg Vorbis)

Now let’s move on to the audio formats belonging to the Lossy category, that is, those always subjected to compression that take up very little space but “sacrifice” a certain degree of audio quality. The main formats in this category are: MP3, AAC, WMA, and Ogg Vorbis. For more information, keep reading, you will find more details about it below.

MP3: in Full Moving Picture Expert Group-1/2 Audio Layer 3, also known as MPEG-1 Audio Layer III or MPEG-2 Audio Layer III.

Differences between digital audio formats (MP3, AAC, FLAC, WAV files, etc.)

What are the main digital audio formats and what are the differences between WAV, MP3, AAC, FLAC and others?

Differences in audio files To discover all types of digital audio formats, you must first understand briefly and synthetically what digital audio means and how it was created.

It all starts with Pulse Code Modulation (PCM), the basis for digital audio, which was founded in 1937 and is characterized by two properties: sampling rate for measuring the waveform amplitude and bit depth for measuring possible digital values.

If the sound is continuous in the real world, this is not the case in the digital world.

To understand the difference, you can think of digital videos that consist of still images that change quickly and give the impression of continuous motion.

It is the same for audio and the amplitude of the sound waves in a digital format is not fluid, but changes according to certain criteria at predefined intervals.

Since I am not an audio technician or physicist to do simple things and understand what digital audio is, I have found a very explanatory analogy that I am trying to explain here.

The analog audio source can be thought of as the water flowing from an open tap and the amplitude of the audio waveform as the water temperature.

Sampling can be viewed as the frequency with which the finger is immersed in the flowing water per second

The more the finger is immersed in it, the more continuous the temperature changes become.

If you put your finger in the running water 44,100 times per second, it’s almost like holding your finger still all the time.

This is the idea behind the sampling rate.

In terms of bit depth, we should think that we’re using a thermometer instead of the finger.

If the water temperature is higher than that of the surrounding area, we will say that it is hot, otherwise it will be cold if it is below it.

Instead of only 2 options, we could mark 16 possible values for measuring the water temperature.

The bit depth can be viewed as the number of values with which the thermometer is to be used to measure the temperature. The more they are, the more accurate information is obtained.

Without losing ourselves technically, we are now seeing the most important digital audio file formats and their differences.

1) WAV and AIFF are lossless (i.e. uncompressed) PCM-based audio container formats with some minor changes in data storage.

.WAV or Wave is the standard format when you take a CD out of your computer (CD ripping).

A WAV and an AIFF can be converted into each other without changing the quality.

These audio formats are suitable for a stereo system (2 channels), they are sampled at 44.1 kHz (or 44100 times per second) with 16 bits (“CD quality”) and the files are approximately 10 MB per minute.

2) Lossless formats: FLAC (Free Lossless Audio Codec), ALAC (Apple Lossless Audio Codec) and APE

These formats compress audio using algorithms.

The difference between compressed files and FLAC files is that FLAC is specifically designed for audio and therefore has better compression rates without data loss.

As a rule, a .FLAC takes up half of the storage space of a WAV in megabytes and maintains the “CD quality”.

A FLAC can be converted to WAV without loss of quality and is the preferred format for those who want to listen to music with the best quality and great speakers.

3) Loss formats: MP3, AAC, WMA, Vorbis

.MP3 and .AAC files are the most common formats when you need to store music on a computer or phone and need to share or download music on the network and the Internet.

MP3 is a highly compressed “lossy” format that sacrifices a certain amount of audio quality for a significant gain in file size.

An MP3 has a size of approximately 1 MB per minute.

The difference to lossless formats is that if you convert the file to a less compressed format like WAV, the quality sacrificed during compression will not be restored.

The various lossy formats use different data storage algorithms, so they vary the size of the files with the same quality. For lossy formats such as MP3, the audio quality is measured using the bit rate value, which is generally specified in “192 kbit / s” or “192 kbit / s”.

The higher the bit rate, the more detailed the sound becomes.

Lossy and Lossy Digital Audio Formats: Audio Codec Guide

In recent years, the way we listen to music has changed a lot, also thanks to the Internet, which has allowed a great diffusion of digital audio files. In a short time we went from vinyl to CD, to online music transmitted in high resolution.

An analog sound to be handled by a computer must become digital. To maintain the exact fidelity of the original audio, you must write a lot of information, thus producing heavy files that take up a lot of disk space. Hence the need to reduce the size of the audio file to save space on various storage media, such as hard drives, but also to take better advantage of the available bandwidth for transferring and listening to files.

Digital audio formats

Every day we use multimedia content such as YouTube, online radio or music streaming services, with a quality that is sometimes enough, other times excellent. This is because the files are the result of a data compression process through the use of codecs.

What is an audio codec?

A codec is an algorithm for encoding and decoding the audio (but also video) data stream.
It is used both to compress a file and to convert, for example, an analog to digital file. The difference in digital audio formats lies in the type of compression that determines their quality and, consequently, their size according to the type of codec used.

Types of digital audio formats.

Audio formats can be of three types:

-Loss (with data loss)
-No loss (no data loss)
-Uncompressed

Lossy digital audio formats

Lossy audio formats are compressed files with lost data and information. They allow you to significantly reduce the size of the original file, even up to 90%. The sound quality is lower than the CD-Audio standard because the compression algorithm “cuts” certain frequencies that the human ear has more difficulty perceiving and, therefore, are less relevant, generally the highest (more than 16 -17,000 Hz).

The Lossy audio format is widely used for listening to digital audio, such as streaming (Spotify, Deezer, Apple Music, etc.). Depending on the type of codec used, compression can vary significantly, as does the quality of the listening. The most popular and popular format is MP3 and WMA.

MP3

The most famous and well-known digital audio format. In its entirety, Motion Picture Expert Group-1/2 Audio Layer, 3, developed by MPEG, offers good compression and discrete audio quality, in particular with a bit rate of 192 kbit / s and 320 kbit / s. Although still widely used, better compression algorithms can be found.

OGG Vorbis

The open source format without lossy audio compression offers an excellent alternative to MP3. With the same perceived quality, it allows for greater compression. The high frequencies (above 16 kHz) are wider and wider, offering greater spatiality of sound. Also used in computer games, it is also often used for audio streaming. Spotify music, for example, uses the Ogg Vorbis digital audio format from 96 kbit / s to 320 kbit / s in addition to the AAC codec.

WMA

Windows Media Audio is Microsoft’s proprietary digital audio format. Encrypted WMA offers excellent compression and good audio quality at high bit rates, but at the same time little compatibility. Precisely for this feature it is now little used. WMA consists of four different codecs: WMA codec, lossless WMA (lossless), WMA Pro, or WMA Voice.

AAC

The Advanced Audio Coding Format (AAC) is part of the MPEG consortium and was born as MP3’s successor. It became famous thanks to Apple that uses it with iTunes, but also thanks to several radios (DABè) that use it to transmit audio. It is the excellent quality and good compression digital audio format used by YouTube, iPhone, Android smartphones and many other devices such as Nintendo and Playstation. The AAC supports 48 audio channels with sampling up to 96 kHz and uses constant bit rate (CBR – Constant Bit Rate) or variable (VBR – Variable Bit Rate) compression encoding. AAC is one of the best lossy codecs, the encoding speed is not among the best.

MPC

Musepack (or MPC) together with AAC vies for the podium as the best lossy digital audio format. The quality is very high, thanks to the VBR encoding that guarantees a good distribution of the bit rate. The peculiarity of this codec, in terms of AAC, is the clarity of the sound, which is very wide and spacious. Good encoding speed, it is ideal for those looking for quality while keeping a small audio file size.

ATTRAC

ATRAC (Adaptive Transform Acoustic Coding) is a lossy audio compression algorithm developed by Sony. Born for MiniDisc (MD) whose production ended in 2013, this codec has not been very successful and is no longer used today.

mP3Pro

Derived from MP3, its peculiarity lies in the fact that it maintains the same quality as an MP3 at 128 kbps but with lower bit rates, from 64 kbps to a maximum of 96 kbps. Compression of the higher frequencies, a painful note from lossy files, occurs through the Spectral Band Replication (SBR) algorithm. The result is space savings at lower bit rates, but also less dynamic and unclear sound.

Dolby Digital

Dolby Digital is a multi-channel audio encoding system, used primarily in DVD, film, and digital television. Contrary to what one might think, it is a lossy audio format, therefore compressed with loss of information. Known as Dolby Digitale 5.1, it works with a minimum bit rate of 96 kbit / s up to a maximum of 640 kbit / s. On DVD, it maintains an average of 192 kbit / s in stereo audio and up to 448 kbit / s in 5.1 signals

Lossless digital audio formats

Lossless audio formats are compressed but lossless files. They maintain the original audio quality, without degrading its characteristics in any way, while managing to compress certain information up to 40-50%. The most popular and widely used Lossless Codec format is the FLAC (Free Lossless Audio Codec) file. Apple has produced its own lossless format called ALAC (Apple’s Lossless Audio Codec) that iTunes uses.

Lossless files offer the quality of a CD (reported as standard), but to maintain fidelity, the dimensions will be larger and take up more disk space than Lossy, but still half the original file.

FLAC

FLAC (Free Lossless Audio Codec) is a codec released under a free software license with lossless data compression. Extended and compatible with most audio devices, the FLAC codec compresses data from a minimum of 30% to 50%, compared to the original file, while maintaining the perceived quality unchanged.
A Flac file can be 8, 16, or 24-bit deep and has a sample rate of up to 192 kHz (Flac Hi-Res).
Various music audio streaming services like Deezer Music, QoBuz, Tidal offer high quality music equal to or higher than the CD standard using this format.

Lossless wma

WMA Lossless is the lossless version of Microsoft’s WMA Lossy codec. It offers good and fast compression. Although it is proprietary, it can also be played by VLC Media Player, WinaAmp, RealPlayer and others.

A THE C

ALAC (Apple Lossless Audio Codec), also known as ALE (Apple Lossless Encoder) is an audio codec developed by Apple in 2004. In 2011, the source code was made available under an open source license. Primarily used by iTunes, other online music services have also used it in recent years. Excellent audio quality and fast decoding, but slightly less compression than FLAC files.

Advantages and disadvantages of the main digital audio formats

CDA:

Advantage
· It is the most standard digital format of all.
· Contains Digitized Stereo Music
· Play all audio spectrum
WAV (AIFF):

Advantage:
· It can contain other resolutions or even be monophonic.
· It can be considered a lot to record voices.

Disadvantages:
· It is considered insufficient for music.
· The most common are 16-bit and 44.1kHz.
· 8 bit 22kHz monophonic WAVs were only capable of reproducing this resolution.

MP3:

Advantage:
· It is adaptable for most devices.
· It is very accessible.

Disadvantages:
· You can force to pay for the use of codecs.
· Contains too many losses, making them clearly insufficient for the quality of MP3 players.
· Adds obvious losses in the stereo image, permanently missing the highest frequencies.
· It is one of the worst in audio quality.
· The higher the resolution, the more the MP3 will occupy.
· It also affects the definition and timbre of the instruments.
· It also removes certain sounds that move at the same frequencies as another louder sound.
· Add excessive modifications to the original music.

WMA:

Advantage:
· Improve MP3 quality.
· There does not seem to be an advantage to using a proprietary format having free alternatives.
· All Windows and many MP3 players support it natively.

Disadvantages:
· Over the years it may become obsolete or discontinued by Microsoft.
· Add artifacts and losses similar to MP3, although lighter.

OGG (Vorbis):

Advantage:
· It would be the equivalent of MP3 and WMA but free and free.
· The code of the codecs is open.
· It is available to the community, which can continue to improve it.
· It has excellent compression rates.
· Quality superior to that of WMA and much superior to MP3.
· Sounds better than a 192 Kbps MP3
· Adds a certain artificial brightness at high frequencies, the losses produced by psychoacoustic theory being much lower.

ATRAC3:

Advantage:
· ATRAC3 plus in an improved ATRAC format.
· Cuts at certain frequencies are auditively seen in secondary and treble instruments.

M4A / MP4 / ACC:

Advantage:
· Contains ACC audio.
· They are capable of playing video.
· The quality of the AAC is much higher than that of the MP3.
· Adds some distortion in the mid frequencies and digital artifacts in secondary instruments.

MPC (musepack):

Advantage:
· It is free and free.
· Excellent sound quality.
· It offers the best quality of all and the losses are practically negligible.

Disadvantages:
· It is one of the most modern and sophisticated formats with loss.
· The resulting files are larger.
· Codecs are not intended for low bitrates.

RA (Real Audio):

Advantage:
· Compress to limits to be able to transmit audio streaming through slow 56 Kbps modems

Disadvantages:
· Requires installation of Real Audio player.
· Slow, heavy and full of advertising.

APE (Monkey Audio):

Advantage:
· It is a lossless format.
· We compress but when unzipping we get the same files intact.
· Contains the full disk wave.

Disadvantages:
· It is a proprietary format.
· It has a discreet support on the platforms.
· Slow decompression.

FLAC:

Advantage:
· It is a free lossless audio format.
· The quality is equal to that of the APE.
· We use less processor.
· It is multichannel (accepts all streaming).
· Avoid annoying shorts.
· It is very compatible.

What are the digital audio formats?

PCM, Wav, Aiff. Compression. Mp3, Ogg, Wma.

Working with digital audio is almost a chore for puzzle specialists. Since audio is saved on the computer and all computer files have extensions, we have to interpret each acronym and abbreviation.

The extension is the end of the file after the name and period. It is used to know what type of file it is, whether it is a text, a video or an audio. There are many extensions and they are all sure to sound familiar to you: WAV, RM, MP3, WMA, OGG … Let’s play, then, to decipher puzzles and see what each of these acronyms means.

UNCOMPRESSED DIGITAL AUDIO FILES

.PCM

It is not a file type or format, but a technique of transforming analog to digital audio without any compression. (1) Therefore, we do not see audios with the pcm extension. We work with PCM when digitizing, but we always keep files with one of these extensions:

.WAV: (Wave, wave in English)

It is the most widely used uncompressed digital audio format. It belongs to Microsoft / IBM.

.AIFF: (Audio Interchange File Format)

It is similar to WAV but for Apple Macintosh or MAC computers.

.CDA

: These are the audio tracks recorded on Compact Disc that also use the PCM system.

All uncompressed files are large. Approximately 10 megabytes for every minute of audio. These are the formats used to store audio at a professional level since the quality is very good. But when we don’t need that much quality and we’re short on space, it’s time to use file compression.

AUDIO COMPRESSION

Compressing is reducing and whenever we reduce we lose something. The same is true for digital audio. The latest advances have allowed compression to be done with the least possible loss of quality, but there always are. Against that, much has been gained in reducing the size of the files.

While a 4-minute audio in WAV format takes approximately 40 megabytes, that same audio, compressed to MP3, can reduce its weight to 4 megabytes, 10 times less. And apparently, they sound the same. (2)

SAVE WITHOUT COMPRESSING

When working in production, it is always recorded in WAV, without compression. In that same way it is edited and mixed. If the final result of the edition is an audio to be uploaded on the Web or saved on the hard drive of a computer, we can compress it to mp3 but with a quality of no less than 160 kbps.

If, on the contrary, the production has as its final destination to be recorded on a CD, never compress, always leave the audio in WAV and burn it that way on the CD.

1. How does compression work?

It is not about wrinkling or crushing the audio. Most audio compression systems take advantage of a “defect” in our ears to reduce file size. It is called masking.

Masking is a property of the human ear that prevents it from distinguishing two frequencies close together within the same range, one masking the other. For example, if a sound with a frequency of 12 Khz and another of 12.2 Khz sounds at the same time in a song, we could remove one of the two without being noticed when listening to it.

In this way, the compressor “subtracts” the masked frequencies, which reduces the number of bytes. And fewer bytes in computing translates into smaller files, but not shorter. The song, when compressed, lasts as long as it is uncompressed.

2. Quality of compressed files

We saw in the previous question that digital audio has two parameters: the sampling frequency (the optimum is 44.1 Khz.) And the resolution or size of each sample (8 or 16 bits). By compressing, we add a third parameter to these two, the bitrate. It is the amount of kilobytes per second (kbps) and refers to the quality of the compression.

• A lower number of Kbps, more compression, smaller file size, but lower quality.

• A higher number of Kbps, less compression, larger file size and more quality.

A compressed audio at 128 Kbps has a higher compression level than a 256 Kbps one. That means that 128 is a smaller file and less quality than 256. Although you must have a cat’s ear to distinguish between both!

VARIABLE OR CONSTANT BIT

Some files have a constant bit rate per second (CBR Constant Bit Rate) and others have a variable one (VBR Variable Bit Rate). The constant is always the same for all audio, for example 128 kilobytes per second. In the variable method, what the compressor does is use more bits when there are parts of the audio where there are more frequencies and it cannot mask all of them.

COMPRESSED FILE FORMATS

Mp3 (MPEG-1 Audio Layer 3)

It achieves high compressions without much loss, although it all depends on the quality of the compression we use. 128 Kbps and below is not recommended.

Although mp3 is the most widely used compression standard, especially for audio on Web pages, the great drawback is its patent. So any player or editing software that wants to use it has to pay for it.

.OGG (Vorbis)

As a result of this patent, the Xiph.org Foundation developed in 2002 a completely free codec (5) for audio compression. Similar in characteristics to mp3, it is beginning to be used a lot on the Web and in some players since manufacturers do not have to pay the costs of the patent. At this point, it is difficult to completely replace the mp3 but it is eating up a lot of ground.

.AAC (Advanced Audio Coding)

The compression level is higher than mp3 (MPEG-1) without major loss of quality. AAC is one of the codecs used in the new MPEG-4 compression standard. This audio format is used in players like the iPod and in some of the new digital radio systems. AAC is shaping up to be the successor to the mp3.

.RAM (also RM or RA)

They are the files of the Real Network company for audio. The problem is that its reproduction and edition is very limited to software from the same company and few others.

.WMA (Windows Media Audio)

It is Windows’ bet on compressed formats. It is like a WAV, but smaller and less quality. While mp3 and ogg files are played by almost all players and editors, the same is not the case with wma files, so it is rarely used.

. AA3 (ATRAC – Adaptive Transform Acoustic Coding)

Format invented by Sony. It is the one used by minidisc recorder-players.

What are digital audio formats

Digital audio formats are basically containers. And the differences between them are fundamentally in:

Whether or not they are compressed.

If they are compressed, in the quality of compression.

The type of labeling they can support.
Digital audio formats

MP3

It is the best known, popular and most widely used. They are known by their “.mp3” extension.

It was developed by Moving Picture Experts Group, so that it was part of the well-known MPEG-1 and MPEG-2 standards.

Its fundamental characteristic resides in the fact that the technology behind it performs a compression of the sound sequence, resulting in a really small file, which normally occupies half of the original file. To achieve this, the loss of certain sounds is necessary, which supposedly cannot be heard by the human ear.

Audio formats

WAV

Developed by the Microsoft and IBM companies, this format, whose name comes from the acronym WAVE (Waveform Aujdio File Format), is currently one of the audio formats that do not have compression in the data, therefore they present an excellent quality.

They are known by their “.wav” extension.

On the other hand, this format has the peculiarity that it includes support for almost all current audio codecs. This makes WAV one of the most widely used formats in the field of professional sound, since the sound is captured with parameters of 44100 Hz and at 16 bits, the same quality can be obtained as on a CD.

On the contrary, one of the disadvantages of this format is that it has a limitation in recording, since it can only capture a maximum of 6.6 hours in the same file at maximum quality.

Audio formats

AIFF

The AIFF (Audio Interchange File Format) format is very similar to WAV. It was born as an answer from Apple to Microsoft’s WAV, being initially only compatible with MAC computers. Currently it can also be used in Windows.

Due to its characteristics, AIFF, together with FLAC and WAV, are usually the most widely used formats in the professional field of audio.

WMA

The WMA (Windows Media Audio) format is a music file format created by Microsoft.

One of its main characteristics is that those files that have been compressed in WMA format take up less space than MP3 files, which also implies a reduction in their quality. Therefore, it is a lossy audio compression format.

OGG

OGG audio formats are compressed audio files, which means that they have a size that allows them to be transmitted via WIFI, but at the same time they avoid the damages that are usually generated in the compression process.

For example, Spotify uses these OGG formats.

Audio formats

FLAC

When we talk about the FLAC (Free Lossless Audio Codec) format, we are referring to a codec free of audio compression and without loss of quality.

Emerged within the community responsible for the OGG project, FLAC has become one of the WAV format’s strongest competitors, due to its advantages in terms of sound quality.

Its objective is to reduce the size of the original file, eliminating data that is usually known as “waste”, without causing loss of quality.

This is the format used by the Tidal platform, the best high quality audio streaming service.

What is the difference between the different audio formats, and which should I choose?

Lossless formats: WAV, AIFF, FLAC, Apple Lossless and others

In summary, there are two types of sound quality: lossless and lossy. Lossless music preserves the sound quality of the original source – in most cases, CD – intact, on the other hand, lossy music compresses the file to save space (in exchange for decreasing quality). Lossless formats include the following formats:

–WAV and AIFF: Both are uncompressed formats, making them exact copies of the original sound source. The two formats are essentially the same quality; they simply store the data differently. AIFF was created by Apple – you will see it often in its products – but WAV is much more universal. However, since they are not compressed, they take up too much unnecessary space. Unless you are editing sound, we do not need to use this format.

–FLAC: Free Lossless Audio Codec (FLAC). It is the most used lossless codec, it is a good option if we want to store our music without losing quality. Unlike WAV and AIFF, it uses compression, taking up less space. However, it is still a lossless format, which means that the sound quality is the same as the original source, so it is better for listening than WAV and AIFF. It is also free and free software, which is useful if you like to take a look at how it works.

-Lossless Apple (Apple Lossless): Also known as ALAC, it is similar to FLAC. It uses compression, although it is made by Apple. Its compression is not as efficient as that of FLAC, so the files will be slightly larger, but it is compatible with iTunes and iOS (FLAC not). Therefore, if you use iTunes or iOS as the main software for listening to music, you should choose this format.

–APE: It is a very high lossless compression file, which means you will save more space. The quality is the same as FLAC, ALAC and other lossless files, but it is not compatible with most players. On the other hand, it makes the processor work more to decode because it is so compressed. Generally, I would not recommend using this format unless you are very concerned about space and have a compatible player.

Lossy formats: MP3, AAC, OGG and more

For day to day, we are more likely to use lossy formats. They save significantly more space, and if they have a high enough bitrate, it will be very difficult to distinguish the quality of the original source. The most commonly used formats are shown below:

–MP3: MPEG Audio Layer III, or MP3 for short, is the most common lossy format. So much so that it has become synonymous with music downloads on the internet. It is not the most efficient f-format of all, but it is certainly the most compatible, making this the first choice of lossy sounds.

–AAC: Advanced Audio Coding, also known as AAC, is similar to MP3, although slightly more efficient. Which means that the files take up less space and with the same sound quality as MP3. And, with Apple’s iTunes making it so popular, it’s as compatible as MP3.

–Ogg Vorbis: The Vorbis format, often known as Ogg Vorbis due to the use of the Ogg container, is the free software version to MP3 and

–AAC. Its main attraction is that it is not restricted by patents, but that does not affect you as a user – in fact, despite being open it is of similar quality, and much less popular than MP3 and AAC, so not all players support it. . I do not recommend it unless you are interested in being open source.

–WMA: Windows Media Audio. Microsoft’s proprietary format, similar to MP3 or AAC. It really doesn’t offer any advantage over other formats, and it’s not very well supported.

So which one should you use?

Now that we have seen the differences between each format, which one should we use for our music? In general, we recommend using MP3 or AAC. They are compatible with most players, and the quality of both is very similar to that of the original source if encoded with a high bitrate. Unless you have specific needs, MP3 and AAc are the most recommended options.

However, there is something to be said for storing music in lossless formats like FLAC. Although we probably won’t notice higher quality, it is good for storing music if you plan to convert it to other formats later – as converting from one lossy format to another. Lossy (eg from AAC to MP3) will produce lower quality files.