Today, most of the audio recordings that people listen to almost every day are presented in the form of universal MP3 files, since they are the most common and demanded in terms of the format for storing audio information. Now we will consider the nature of this type of data, the history of the codec itself and the principles of coding. In addition, practical tips will be given on how to convert the MP3 file to a different format or to create MP3 from files of a different type than the one mentioned. This is done quite simply, however, subject to the use of special programs.
What is an MP3 format?
Today, few people think about what constitutes sound in this format. In principle, if you do not get into the jungle of audio coding principles, it is enough to say that this is audio information in a compressed form.
Previously, the basic format in which music files were stored was WAV. Such information took up too much space on the hard drive, and over time this type of data became quite inconvenient. In particular, this affected those times when music began to be actively posted on the Internet. It was then that there was a need for audio compression in order to reduce the amount of source material. Indeed, if you transfer the format from WAV to MP3, the space saving becomes immediately noticeable (the track takes 10 times less space, moreover, the structure of the new format was such that even certain information about the track can be entered in the description, for example, the name of the artist, the track itself, album, year of release, as well as post some basic technical specifications of audio).
For this, special text fields called ID3 tags are responsible in the file structure, after which all information can be displayed in the player window.
History of occurrence
In the modern world, there is a lot of disagreement about who created this data type. Although it is generally accepted that the MP3 format is, so to speak, a variation of the more general concept of MPEG created by Moving Pictures Experts Group, the Fraunhofer institute group, which was the first to use the Lame MP3 Encoder codec, became the true developer of MP3 coding technologies. He was the first standard in this area.
This happened in the mid-90s, however, then such audio (MP3 files) could be reproduced exclusively with the help of software players, so there was no talk of the widespread introduction of new technology. Only after the first household players and portable players were released, this standard began to be applied as a single one. However, today he has a lot of competitors. This is due only to the basic principles of coding, due to which it is possible to reduce the amount of source material.
Principles of audio coding and compression
The most important thing in the process when the source material needs to be converted to MP3 format is cutting out everything that is not perceived by the human ear at the household level. Roughly speaking, the track will have a bitrate of 320 kbps, which is 128 kbps with a standard sampling frequency of 44 100 Hz - it’s difficult to notice the difference in sound. That is why in the process of compression, a certain characteristic of the audio decreases.
Only a person with a very subtle hearing or a sound engineer using specialized programs can perceive such a difference. De facto with a compressed MP3 format in the studio, almost no one works. It is involved only at the stage of final mastering and post-production, when all tracks need to be equalized in volume, normalized, the field of which to release a full-fledged album. We will dwell on this a bit later.
Basic sound characteristics
As you know, any audio material has several basic parameters by which its sound quality is determined. And the MP3 format is no exception. The most important characteristics are sample rate (the most common standard is 44.1 kHz), bit rate (128 kbit / s is taken as the main standard) and sound mode (mono, stereo, surround 5.1, 6.1 or 7.1). In general, the last parameter is not always taken into account, and the main emphasis in determining the quality of any track is reduced exclusively to the first two characteristics.
The most common formats of music, other sound files and the connection between them
As for the direct competitors of the universal MP3 format, today they can be counted quite a lot. As already clear, in the course of its insolvency in terms of household storage, the WAV format has not been used as the final format for a long time. But for professional sound studios, it remains, so to speak, the basic option for work. Especially when recording vocals or live instruments. Recorded material is transferred from WAV to MP3 only at the final stage.
However, music can be presented in some other popular formats today. So, for example, very often (especially on the Internet) data types such as OGG, AIFF, AMR and many others are used. But the real competitor for MP3 has become the latest and better type of audio FLAC. Of course, for MP3 you can bring all the indicators to maximum values, however, FLAC is an order of magnitude higher in playback quality. In addition, it is a single file, and the division into tracks occurs directly at the expense of a software or consumer player. In other words, the listener does not see each track separately, but can switch between tracks in the player. For the MP3 format, it would seem, you can also create one file by combining several tracks in it. But fast switching between tracks in this option will become impossible (you will have to use the usual fast-forward, no more).
However, not everything is so bad. The fact is that all the formats of music or audiobooks known today can easily be converted between themselves, even with the initial parameters of the sound material being preserved. Almost all programs for processing and converting sound, called audio editors and converters, are based on this. Any program of this type (MP3 editor or converter) recognizes both the source and the final type of sound file, and, as is already clear, it can perform both direct and inverse conversion. Let us explain this with a specific example.
Wave representation of MP3 files in audio editors
To process sound today, several types of software are used. First, let's focus on narrowly targeted applications called audio editors. Among them, the most prominent representatives can be called such giants as Sony Sound Forge, Sintrillium Cool Edit Pro, which was subsequently bought by Adobe and changed its name to Audition, Acoustica Mixcraft, ACID Pro and many others.
The principle of work in them is that for convenience, any MP3 audio program is presented in the classical wave form, as it was originally used for WAV files. Such an approach predetermines the appearance of sufficiently wide possibilities for editing sound material of any type as the usual WAV format. In addition to the fact that here you can carry out the simplest operations of copying, cutting, pasting, etc., changing the frequency characteristics and bit rate becomes quite simple, not to mention the use of a huge number of additional effects that are connected to the studio through the DirectX bridge or universal hosts Vst.
In the simplest version, you can convert the format to MP3 using the standard file menu, which has the line “Save As ...” (Save As ...) or there is an export function. Thus, the whole process is reduced only to the choice of the final format (we have MP3 as an example) and activation of the save mode. In this case, the conversion will be done automatically while maintaining the current settings of parameters and frequency characteristics. Do not like the initial version? There is nothing easier to change the format to MP3, having previously specified higher parameters. However, it is worth considering one point: if the quality of the source material is too poor, it will not work to achieve its special improvement even with professional means. Here you will have to use special tools for restoration of audio, involving various kinds of filters, etc. For an uninitiated person this will cause a lot of difficulties.
As already clear, there is absolutely no difference what we have before us - MP3 audio books, music, or just recorded speech or noise. By the way, it is unofficially accepted that audio books have a much lower sound quality. This is understandable, because the file should occupy a minimum of space, and the characteristics of sound in speech perception, in general, are not so important. After all, this is not a professional record of some album of a famous group?
However, if you use some standard operations even without specific knowledge, you can still achieve a good result, especially since any application of this type has built-in templates based on which an action is performed. Of course, it will be very difficult to achieve the ideal sound the first time, however, if you study the program and master the principles of its work, then things will go like clockwork, and the result will not be long in coming.
Audio converters
With audio converters, the situation is even simpler. Programs of this type were designed specifically to convert audio formats between themselves quickly and without the explicit involvement of the user. Unlike audio editors, converters, you can say, use some kind of batch mode, that is, they allow in one operation, for example, to convert an MP3 file not in a single copy, but to make several pieces at once. Depending on the capabilities of the application itself, they can be from several tens to several hundred.
Again, the principle of working with such software packages is quite simple. You just need to select the starting material (and, often, these can be files of completely different types), and then set the final format. Next, a special button to start the process is pressed, and at the output the user receives all files of one given type. Their saving, as a rule, takes place in the folder set by default in the application settings, but the saving location, of course, can be changed at your discretion. By the way, the same applies to the main characteristics that will be applied in the conversion process. But any program initially offers the user a certain set of standards that are used for sound files of one type or another. They can also be changed.
The advantage of such applications is that they automate the entire conversion process as much as possible, and it does not take so much time to complete all the processes. True, if you compare them with music or audio editors, in terms of improving the same sound quality, you won’t especially accelerate here.
Music sequencers
We are faced with another type of software products, which for the most part have a built-in MP3, WAV editor, etc. In this sense, they work according to principles similar to audio reactors, but their capabilities are somewhat wider.
First of all, this concerns the fact that the entire musical composition can consist of fragments of various types (MP3, MIDI, WAV, OGG, libraries of VST or DX instruments, etc.). After recording sound or registering parts of all tracks, for example, with virtual synthesizers, after mixing and mastering, the resulting file can be saved in the desired format. Most often it is either MP3, or WAV, or the project file of the program itself. Some applications also have a disc burning function. Want to make an audio CD? No problems! As well as in audio editors, you can perform the necessary operations in a few minutes and get a disc with tracks in CDA format at the output .
If we talk about the advantages of this type of application, it is obvious that just the same combination of several formats, followed by saving or exporting to some of the most common and is their greatest strength. In addition, you should pay attention to the fact that the same superposition of effects or a change in any parameter of the sound track occurs in real time, that is, you do not need to wait for the result - you can hear it instantly, for example, when you turn some knob that controls or another parameter. Naturally, this is only a small part of what such software packages are capable of.
Which is better to use?
Finally, we come to the issue of choosing software for working with the MP3 format or any other in which sound is recorded. As already clear, for ordinary listening to music or an audiobook, a simple player (software or hardware) or a regular DVD player is enough.
To convert files to other formats, so to speak, quickly, audio converters are perfect. But if the output requires crystal clear sound, even by converting one type of file to another, you cannot do without powerful specialized software. Of course, this will take an order of magnitude more time, and without special knowledge, it may not be possible to get the same high-quality MP3 file from the first. However, if you thoroughly study at least audio editors, not to mention professional music studios, the result will exceed all expectations.
Instead of an afterword
It remains to add that the MP3 format here was considered rather briefly, because if you dig deeper, especially get into the technology of restoration and restoration of sound using means to improve the quality of the material, you can write a whole monograph here.
But as for understanding the structure of the MP3 format itself, I think that for most users it will be clear what it is and what principles are laid down in its formation and transformation. However, if you look into the future, so far you can only predict that this type of audio, which is considered the standard today, will undergo drastic changes in the near future. Moreover, apparently, the main emphasis will be placed on improving the sound quality without significantly increasing the size of the files themselves. However, for such assumptions there is every reason, because the same computer technology today is developing at a frantic pace.