MAIN AUDIO FORMATS

Even the audio formats differ in their versatility and level of compression, and even if they are not as numerous as the video formats, it is better to look at the properties to get satisfactory results according to the requirements of our work.

Microsoft Wave [Extension: WAV] It is Microsoft’s proprietary format and is certainly the most widely used. This diffusion depends on commercial aspects and the fact that it is the most supported among the competitors. It has various compressions and is a versatile and highly editable format. For this reason, it is suitable for general digital audio, both for multimedia publications (although there are certainly better formats) and for desktop video (real standard). An excellent program for processing wave files (but also other formats) is CoolEdit.

MPEG Audio (extension: MPG / MP3) MP3 stands for MPEG1 Layer3. The MPEG algorithm, the basis of MP3, emerged from the need to develop a world standard for the representation of moving images and audio. This standard was developed in 1988 for the treatment of audio and video signals and has the special feature of compressing files and reducing them by 12 times compared to their natural size.

This high-compression format is based in particular on theories of psychoacoustics: each individual has a hearing that is sensitive to frequencies from 20 Hz to 20 kHz, and in particular the man perceives sounds between 2 and 4 kHz better. In addition, some sounds mask nearby frequencies so that you cannot hear all of the sounds.

These considerations have led to the development of an algorithm that eliminates all “redundant” noise for the human ear and achieves a high level of file compression and sound quality that is comparable to the digital and can be downloaded directly to your PC.

MP3 enables good results, making small and high quality playback compatible. An established audio standard is the MPEG Layer3 version, which produces very small files of excellent quality, an excellent compromise when duplicating and creating audio files on CD. The XingMPEG encoder is an excellent software for creating MP3s.

Given the prevalence and importance of the topic on a legal level, let’s find out what it is and what benefits we can achieve by using this MPEG format.

An audio CD generally contains 60 to 78 minutes and is characterized by a quantization level of 16 bits and a sampling rate of 44.1 kHz, ie 44,100 samples per second. The quantization level describes the maximum number of intensity levels that a single sample can hold: for example 8 bits = 256 levels (28), 16 bits = 65,356 levels (216). The higher the number of levels that the signal can assume, the more precise the signal reproduction.

There is approximately 650 MB of data on a normal audio CD.

Conventionally, to reduce the size, we can work in two ways: 1) Reduce the quantization: that is, convert the samples from 16 bits to 8 bits, but lose the dynamics, quality and get a lot of noise; 2) Reduce the sampling frequency. As a result, the frequency range would decrease in the event of a loss of resolution.

The MPEG format, on the other hand, reduces the amount of information stored and therefore significantly reduces the size of the files by filtering out unimportant audio information according to the models developed on this basis. From research on the perception of the human ear, you decide which information is important and which is not . These studies have enabled us to know how our brain analyzes sounds, except irrelevant ones that are imperceptible (e.g. ultrasound).

The MPEG audio format also performs this process of removing intelligent weak signals. So if there is a strong signal, the weakest signal is not perceived.

When using a high compression rate, the MPEG encoder eliminates parts of audible information that are still of minor importance. With a slight compression rate, the difference to the uncompressed original is minimal.

Layers I, II, III can be viewed as the layers through which the MPEG format has evolved. All layers are based on the same perceptual coding scheme, the complexity of which increases for each of them. Layer II has superior quality at lower bit rates than Layer I; However, the most complex coding system currently available is Layer III,

 

MP4 (Extension: MP4) is an audio compression technology recently launched by Global Music Outlet (GMO) under license from AT&T Labs (January 99). As you understand, it is a further development of the MP3 format and seems to offer the ability to offer it a higher compression factor, which should even reach a factor of 16. Although the name is very similar, conceptually it has nothing to do with layer 3 and is actually in direct competition with it. Compressed MP4 files are presented as executable Win9x or WinNT files and offer the relatively encapsulated player.

Audio exchange (extension: AIF / AIFF) Format created to standardize the various audio standards between PC and Machintosh.

Microsoft NetShow (Extension: ASF) Audio extension of the format for streaming audio / video on the web.

Yamaha SoundVQ [Extension: VQF] Audio format released by Yamaha in direct competition with MP3.

Everything you need to know about audio files … compressed and uncompressed

Regardless of whether you’re listening to MP3 files or high-definition audio, it’s time to find out exactly which file format is best for your needs.

As you organize your digital music collection, you may be impressed by the number of different audio file formats you have collected over the years. For this reason (and since a good review doesn’t hurt anyone) we’d like to deepen the discussion of the most common audio file formats, explain the differences and explain why you should be interested in learning more about them. Whether you’re listening to low quality MP3 files, slightly better AAC tracks, or high definition audio in FLAC or WAV, it’s time to find out exactly what you’re dealing with and which file format best suits your needs.

File formats and codecs

Below is a list of all common audio file formats and the differences between them.

-AAC (no high resolution): Apple’s alternative to MP3. It’s a compressed audio format, but it sounds better than MP3 and is used to download music from iTunes and stream via Apple Music.

-AIFF (high resolution): Apple’s alternative to WAV, but with better metadata support. It’s an uncompressed and lossless format, but it’s not very popular.

-DSD (High Resolution) – The uncompressed single bit format for super audio CDs. It is available in the 2.8 MHz, 5.6 MHz and 11.2 MHz variants, but due to its high-quality codec it is (currently) not suitable for streaming.

-FLAC (High Resolution) – This lossless compression format supports high-resolution sampling rates, takes up about half the WAV space, and stores metadata. It is license-free and is the preferred format for downloading and storing albums in high resolution or CD quality. The disadvantage is that it is not compatible with Apple (therefore it is not compatible with iTunes).

-MP3 (not high definition): Lossy, compressed format that guarantees small file sizes, but is far from the best possible audio quality. However, it is still very convenient for storing music on smartphones and other mobile devices and is widely used.

-MQA (High Resolution) – A lossless compression format with high resolution files for more efficient transmission. It is used for high-resolution streaming from Tidal Masters and other similar services.

-OGG (not high resolution): Sometimes you can find him by his full name, Ogg Vorbis. An open source and compressed alternative to MP3 and AAC that is not limited by patents. This format is used (at 320 kbit / s) to stream Spotify.

-WAV (High Resolution) – The standard format in which all audio CDs are encoded. Excellent sound quality and no compression, which means large files (especially for high-resolution files). However, metadata (album art, artist information, and song title) are hardly supported.

-WMA Lossless – An uncompressed embodiment of Windows Media Audio, but is no longer supported by smartphones or tablets.

The 10 most common audio formats: which one to use?

Audio files are available in all types and sizes. And although we are all familiar with MP3, what do you think of AAC, FLAC, OGG or WMA? Why are there so many audio standards? Which are important and which to ignore?

It’s actually quite easy to find that all audio formats fall into three main categories. Once you know what the categories mean, you can simply choose a format within the category that best suits your needs.

Uncompressed audio formats

Uncompressed audio consists of actual sound waves that have been captured without further processing and converted into a digital format. As a result, uncompressed audio files are usually the most accurate, but take up a lot of space, about 34MB per minute for 96-bit and 96-bit stereo.

Audio file format: PCM

PCM stands for Pulse Code Modulation, a digital representation of analog audio signals. Analog tones exist as waveforms, and in order to convert a waveform into digital bits, the tone must be sampled and recorded at certain intervals (or pulses).

This digital audio format has a “sample rate” (how often a sample is taken) and a “bit depth” (how many bits are used to represent each sample). No compression is required. The digital recording is an almost exact representation of the analog sound.

PCM is the most common audio format used on CD and DVD. There is a PCM subtype called Linear Pulse Code Modulation, in which samples are taken at linear intervals. LPCM is the most common form of PCM, so the two terms are almost interchangeable at this point.

Audio file format: WAV

WAV stands for Waveform Audio File Format (at some point also called Audio for Windows, but no longer). It is a standard developed by Microsoft and IBM in 1991.

Many people believe that all WAV files are uncompressed audio files, but that’s not exactly true. WAV is actually a Windows container for various audio formats. This means that a WAV file may contain compressed audio, but this is rarely used.

Most WAV files contain uncompressed audio in PCM format. The WAV file is just a container for PCM encoding, so it is more suitable for use on Windows systems. However, Mac systems can generally open WAV files with ease.

Audio file format: AIFF

AIFF stands for Audio Interchange File Format. Similar to how Microsoft and IBM developed WAV for Windows, AIFF is a format developed by Apple for Mac systems in 1988.

Similar to WAV files, AIFF files can contain several types of audio formats. For example, there is a compressed version called AIFF-C and another version called Apple Loops that is used by GarageBand and Logic Audio. Both use the same AIFF extension.

Most AIFF files contain uncompressed audio in PCM format. The AIFF file is just a container for PCM encoding, making it more suitable for use on Mac systems. However, Windows systems can generally open AIFF files with ease.

Lossy compression audio formats.

Lossy compression occurs when some data is lost during the compression process. Compression is important because uncompressed audio takes up a lot of space.

In other words, lossy compression means that the sound quality and fidelity for smaller files are affected. If you are hurt, you will hear artifacts and other oddities in the audio. But if done correctly, you won’t feel the difference.

Audio file format: MP3

MP3 stands for MPEG-1 Audio Layer 3. It was released in 1993 and is becoming increasingly popular. It is the world’s most popular audio format for music files. There is a reason why we had “MP3 players” but no “OGG players”!

The main purpose of MP3 is in three ways: 1) removing all audio that is out of the normal human hearing range, and 2) reducing the quality of inaudible sounds, then 3) compressing all the other audio as efficiently as possible.

Almost every digital device in the world with audio playback can read and play MP3 files, be it PC, Mac, Android, iPhone, Smart TV or anything else. If you need a universal device, MP3 will never disappoint you.

Note: MP3 is not the same as MP4!

 

Audio file format: AAC

AAC stands for Advanced Audio Coding. It was developed in 1997 as the successor to MP3 and although it has become popular as a format to be used, it has never surpassed MP3 as the most popular.

The compression algorithm used by AAC is much more advanced and technical than MP3. So if you compare the same recording in MP3 and AAC format with the same bit rates, the AAC generally has better audio quality.

Although MP3 is a more popular format, AAC is still widely used today. In fact, this is the standard audio compression method used by YouTube, Android, iOS, iTunes, later Nintendo laptops, and later PlayStation.

Audio file format: OGG (Vorbis)

OGG represents nothing. In fact, it’s not even a compression format. OGG is a multimedia container that can contain all types of compression formats. However, Vorbis files are most commonly used. Therefore, these audio files are called Ogg Vorbis files.

Vorbis was first released in 2000 and is growing in popularity for two reasons: 1) it conforms to the principles of open source software and 2) it works significantly better than most other lossy compression formats (ie) this results in a smaller file size for an equivalent sound quality.

MP3 and AAC are so strong that OGG struggles to get into the spotlight – not many devices support them natively, but they do improve over time. It is currently used primarily by supporters of hardcore open source software.

Audio file format: WMA (lossy)

WMA stands for Windows Media Audio. It was first published in 1999 and has gone through several developments since then, always keeping the same name and WMA extension. It is a proprietary format created by Microsoft.

Similar to AAC and OGG, WMA should fix some of the errors in the MP3 compression method, and it turns out that WMA’s approach to compression is very similar to that of AAC and OGG. Yes, in terms of the quality of objective compression, WMA is really better than MP3.

However, since WMA is proprietary, it is not supported by many devices and platforms. In addition, it offers no real advantage over AAC or OGG. If MP3 is not good enough, it is only more practical to use one instead of WMA.

Audio formats with lossless compression.

The opposite lossy compression is lossless compression, in which the size of an audio file is reduced without loss of data between the source audio file and the compressed audio file.

The disadvantage is that lossless compressed audio files are larger than lossy compressed audio files, up to 2 times 5 times larger for the same source file.

Audio file format: FLAC

FLAC is an abbreviation for Free Lossless Audio Codec. Maybe a bit on the nose, but it has quickly become one of the most popular lossless formats since its launch in 2001.

The good news is that FLAC can compress an original source file by up to 60 percent without losing a single bit of data. What’s even better is that FLAC is a free, open source audio file format, so there are no intellectual property restrictions.

FLAC is compatible with most major programs and devices and is the primary alternative to MP3 for music. You basically get the full quality of uncompressed audio with half the file size. That is why many see FLAC as the best audio format.

Audio file format: ALAC

ALAC stands for Apple Lossless Audio Codec. It was developed and published as a proprietary format in 2004, but became open source and copyright-free in 2011. ALAC is sometimes referred to as Apple Lossless.

While ALAC is good, it is somewhat less efficient than FLAC in terms of compression. However, Apple users cannot choose between the two, as iTunes and iOS offer native support for ALAC and no support for FLAC.

Audio file format: WMA (lossless)

WMA stands for Windows Media Audio. We already discussed this in the lossy compression section, but we explained this here because there is a lossless alternative called WMA Lossless that uses the same extension. Confused, I know.

Compared to FLAC and ALAC, WMA Lossless is the worst compression efficiency, but not much. Since it is a proprietary format, it is not suitable for open source software enthusiasts, but is natively supported on Windows and Mac systems.

The most used audio formats

As you can imagine, when we talk about digital formats in the field of sound, the range is wide. When choosing the one that best suits our needs, we need to think about several questions. To do this, the first thing to do is to know the most used audio formats.

We start by clarifying the concepts of bit depth and sample rate, which are essential for understanding how audio formats work. These are two measurements that indicate the quality of a digital audio file.

When we read the specifications for audio formats and find, for example, 32 bit / 192 kHz and 24 bit / 96 kHz, these figures refer to “bit depth” and “sampling frequency”, respectively. They tell us the amount of information transmitted by the different formats and the quality of the sound. The more times a device reads samples, the higher the quality.

Audio formats

-MP3: These files weigh very little for any device to read. The downside is that the quality of compression is sacrificed.
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-WAV (Waveform Audio File Format): These are higher resolution files than MP3, an audio track which is coded with what is called Pulse Code Modulation (PCM). Analog audio tracks are encoded and converted to digital so that they can have sample rates and bit depth.

-AIFF (Audio Interchange File Format): it is very similar to WAV and also uses PCM to encode analog audio tracks and present them in digital format. Indeed, AIFF and WAV files are more or less interchangeable.
In short, when we talk about a file in WAV or AIFF audio format, we are talking about a good quality piece of sound.