Audio formats


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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.

Audio Formats

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.

Audio Formats

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.


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All about Audio formats (2020)

The algorithm used to compress and decompress files is called CODEC (acronym for compression / decompression). “Codec” is software that tells the computer which mathematical operations it must manipulate to compress them and which ones to perform to show them compressed.
Instead, the “format” is a kind of file that contains the codec and integrates it with the system.

Sounds are digitally recorded using a technique called “sampling”: the sound wave is divided into many pieces called samplers.

audio file formats

The quality of a digital audio track depends on:

– sampling frequency, measured Hertz (Hz, number of samples per second). A frequency at 11.025 Hz is suitable for recording voice, one at 22.050 Hz (medium quality) is suitable for recording a tape and one at 44,100 Hz for recording in CD quality. Reducing the sample rate leads to loss of quality.

– from termination, ie. the number of bits used (8.16, 24 to 32) for each ciampione (with 8 bits = 1 byte for 256 options, 16 bits = 2 bytes for 256 * 256 = 65,536 values ​​in the levels, and so on). Converting 16-bit to 8-bit samples cuts the original file in half, but also reduces the quality of the music.
– the number of channels: mono (1) or stereo (2).

bit rate: the product of these three elements: frequency, resolution, and number of channels are defined as bit rate, ie bits per second or bps. From this it can be deduced that every second there are 44,100 recorded values ​​which are then multiplied by the 2 stereo sound channels which are multiplied by 16 as the recording takes place in 16 bits (corresponding to 2 bytes). Then we get:

The bit rate for songs on audio CDs = 44,100 * 16 bit * 2 = 1,411.2 kbps (~ 10.6 MByte per minute 44,100 * 2 byte * 2 * 60)
The bit rate of an audio recording = 22,050 * 8 * 1 = 176.4 Kbps (~ 1.3 MByte per minute = 22,050 * 1 byte * 1 * 60)

Accordingly, compressing by reducing the total length of the file will reduce the average length of the subsequent ones, ie. it will reduce the average bit rate. Therefore, in these cases, the average bit rate becomes the index of the compression scope. For example, if the source file had a bit rate of 1,411 Kbit / if the compressed file had an average bit rate of 320 Kbit / s, we would have reduced by a factor of approx. 4.5.
Loss compression compromises the loss of information and the size of the final file, while a lossless compression must balance the size of the final file with the execution times of the algorithm.

losseless

The most popular lossless audio formats are:

-WAV sampling, Wave file (Waveform Extension), where wave means wave: standard format for audio files in the Windows audio sampling environment; It has large dimensions as it manages sampling frequencies of up to 44.1 kHz, 48 kHz and now also 96 and even 192 kHz, resolution of up to 32 linear bits and allows to store stereo or surround signals with a number
Unlimited in a single speaker file (equivalent to so many channels). The wave format is nothing more than digital recording of real sounds, sounds that have had
originates from a source external to the PC. In a WAV piece of music drums, piano, guitar, bass or
voice is heard in the same way, regardless of the PC to which the file is heard (to
obviously with the same acoustic quality of the hardware components).
-Aif (Apple Audio Interchange File Format or AIFF) similar to WAV format, is a format that generates good sound quality, is compatible with many browsers and does not require plugins. to Apple’s AIFF format. The Au format also manages more efficient quantization methods that allow a reduction in the amount of data by even 4 times the original value at the cost of a modest loss of quality.
-APE (Monkey Audio; .ape): Lost raw format that allows you to reduce the space occupied
our music about 50% (in some cases even more) without loss of quality. This way an album there
wav format has approx. 600 MB, has an average of 300 MB (much more than about 100 MB a
high bit rate and 60 mpc of an mp3, but the quality is identical to the original); I say, on average, because there is
certain types of music where the level of compression is even higher. To listen to songs in this format,
you can use plugins for WinAmp or, better yet, a player that integrates the native as
Foobar 2000. Right now it’s probably the best lossless codec considering a balance between
speed and compression (click here for lossless comparison table).

What are the digital audio formats?

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.

Most popular audio formats

There is a huge amount of audio formats. The most common are formats such as MP3 (MPEG-2 Audio Layer III) and WAV. Usually, the type of format corresponds to the file extension (the letters of the file name after the period, for example .mp3, .wav, .ogg, .wma).

audio formats

A codec is an algorithm for encoding and compressing data in an audio format. Some file types are assigned a specific codec. For example, the MP3 format always uses the MPEG Layer-3 codec, while the MP4 format can use a range of different codecs.

Many times, the notions of codec and format are used as interchangeable. Especially when a format always uses a single codec. However, it is necessary to understand the difference between a format and a codec. In simple terms, a format can be compared to a container in which a sound or a video signal that uses a particular codec can be stored.

Some formats, such as MP4 or FLV, can store both audio and video sequences.

mp3 format

If you don’t know what program you should use to open one format or another audio, we recommend that you use our audio converter. It is compatible with almost all existing formats.

Depending on the type of compression, two types of codecs can be distinguished:

Lossless Codecs

This group of formats records and compresses a sound in such a way that it allows the preservation of its exact original quality when decoded.

The most common lossless coding formats are:

FLAC (Free Lossless Audio Codec – Audio codec, lossless and free),
APE (Monkey’s Audio – Mono Audio),
ALAC (Apple Lossless Audio Codec – Audio codec, lossless Apple).

Loss Codecs

When compressed with loss, a sound undergoes some modification. For example, compression cuts the sound frequencies that are inaudible to the human ear. When decoded, the file will be different from the original in terms of the information stored in it, but it sounds almost the same.

Some of the most common lossy formats are:

MP3
Wma
OGG
AAC

WAV is one of the first audio formats. It is mainly used to store uncompressed audio tracks (PCM) that are identical to audio CDs in terms of quality. On average, a minute of WAV format sound requires about 10 megabytes of memory. CDs are usually digitized in WAV format and then can be converted to MP3 with an audio converter.

MP3 (MPEG Layer-3) is the most widespread sound format in the world. MP3, like many of the other lossy formats, compresses the file size by reducing sounds inaudible to the human ear. Currently, MP3 is not the best format in terms of file size for sound quality, but since it is the most widespread and compatible with most devices, many people prefer to save their files in this format.

WMA (Windows Media Audio) is a format owned by Microsoft Corporation. It was initially introduced as the substitute for the MP3 format, with the highest compression characteristics. However, this fact has been compromised by some independent tests. In addition, the WMA format is compatible with data protection through DRM.

OGG is an open format that supports audio coding by several codecs. The Vorbis codec is the most commonly used in OGG. The quality of compression can be compared to the MP3 format, but it is less widespread in terms of compatibility with various audio players and devices.

AAC is a patented audio format system that has higher capabilities (number of channels, frequency of discretion) compared to the MP3 format. Usually, it achieves better sound quality with the same file size. AAC is currently one of the loss-coding algorithms that offers the highest quality. A file encoded with this format can have the following extensions: .aac, .mp4, .m4a, .m4b, .m4p, .m4r.

FLAC is a common lossless format. It does not modify the audio sequence and the sound encoded with this format is identical to the original. It is frequently used to reproduce sound in high-end audio systems. Its playback compatibility on devices and players is limited, therefore, if desired, it often becomes other formats before listening to it on a player.