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An mp3 is 320kbps, 44100hz, what does this mean?

44100Hz represents the sample rate of the signal. The so-called sampling consists of obtaining the value y of the sound wave at the current moment every unit of time. Sampling is the process of discretizing continuous data (converting an analog signal to a digital signal).
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The sampling method mentioned above is called PCM (Pulse Code Modulation). According to the Nyquist-Shannon sampling law, the sampling rate must be at least twice the highest target frequency. The hearing range of the human ear is about 20Hz-20,000Hz (if you’re curious how loud you can hear, you can click here to test your ears), although recording software often has a 48,000 option Hz, but we can safely conclude: 44100Hz can meet almost all our needs, higher is just a waste of your memory and CPU. More than 48,000 samples are meaningless to the human ear, which is similar to 24 frames per second on a movie. 44100Hz happens to be the standard sample rate for almost all music released. In fact, for vocals and many instruments, high-frequency sounds are noise, so high sample rates can sometimes worsen sound quality (which is why we need to adjust the equalizer).

320 kbps represents your bitrate/bitrate, which is shorthand for kilobits per second, which represents the size of the data used to describe sound. In CD (uncompressed audio file), the bit rate is 1411.2kbps, and the mp3 sound quality to achieve CD quality should be higher than 128kbps/44100Hz (128kbps can be said to be the most common bit rate). Generally, a higher number means better quality. The quality depends on many factors (such as the encoding algorithm). Many times we don’t need too high bitrate: our device can play mp3 and CD without difference (sound/sound card is normal).

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What is bit rate? Knowledge of the MP3 audio format. Part 2

Bitrate is a benchmark indicator of the efficiency of digital music compression.

The bit rate represents the number of bits bps (bit per second, bits per second) transmitted per unit of time (1 second). We usually use kbps (in simple terms, it is per second) clock 1000 bits) as the unit. The bit rate of digital music on CD is 1411.2 kbps (ie recording 1 second of CD music requires 1411.2 × 1024 bits of data). The higher the bit rate of the music file, the more data (Bit) must be processed in a unit of time (1 second), and the better the sound quality of the music file. However, when the bit rate is high, the file size increases, which will occupy a large amount of storage capacity. 8 to 320 kbps.

1. WMA (Windows Media Audio, Windows Media Audio)

As a Microsoft media compression method, it is a part of the technology that only compresses audio data in Windows Media Technologies. The sound quality is similar to MP3 and can be compressed with half the technology of MP3. It has the copyrighted Windows Media Rights Manager and can be played by installing it in WMP (Windows Media Player, Windows Media Player). Due to the strong influence of Microsoft and Windows, as well as major copyright reasons, the major American record companies, EMI and BMG, officially confirmed that they use the WMA method developed and produced by Microsoft. It is believed that this advanced method will become even more popular in the future.

2. MP3 (CBR, VBR, ABR)

MP3 is currently the most widely used and widely used lossy compressed digital audio format. It has been explained above and will not be repeated here.

CBR (constant bit rate)

CBR is the oldest and simplest MP3 encoding (compression) method. When this method is used for encoding, the bit rate of the entire file is the same, in other words, the bit rate used by the MP3 file per second is the same. Although the music file has sections of varying complexity, the encoder always keeps the bitrate constant, unless you use the highest sound quality; otherwise the sound quality of the different sections of the MP3 file will vary. The more complex the passage, the worse the sound quality. Its biggest advantage is that the file size is fixed, which is convenient for calculating storage space.

VBR (Variable Bit Rate, Variable Bit Rate)

VBR is a variable encoding rate MP3 compression method. Its principle is to encode the complex part of a song with a high bit rate and the simple part with a low bit rate. Through this dynamic adjustment of the encoding rate, the sound quality can be improved. additionally obtained and the size of the file. Its main advantage is that the entire song can approximately meet our sound quality requirements, but the disadvantage is that the size of the compressed file cannot be estimated during encoding.

Most MP3 players released now support VBR, but although some machines can play songs in VBR format, they can’t display the playing time correctly. Nowadays, a lot of high-quality MP3 music is encoded in VBR.

What is bit rate? Knowledge of the MP3 audio format.

Digital audio formats are audio signals that are recorded, processed, and reproduced in digital form.

The emergence of digital audio formats is to meet the needs of high-fidelity playback, storage and transmission. Simply put, early analog audio formats had issues with playback distortion and glitches due to media wear. Since the advent of the CD, digital format audio files have become popular, but another problem has arisen: the limitation of the storage volume, and the CD still has the phenomenon of wear. Saving to hard drive (relatively longer storage time) is not a good solution when storage media (mainly hard drives) are still expensive at the time. The rise of the Internet has created a requirement for long-distance file transmission. Under the restriction of bandwidth, the demand to reduce file size has become more intense. All this has led to the generation of lossy compressed digital audio formats from external factors!

In terms of internal factors, with the improvement of computing and coding capabilities, the progress of various acoustic psychological models has promoted the emergence of various lossy compressed digital audio formats. Some of the most commonly used audio formats in MP3 players are briefly introduced below: MP3 (CBR, VBR, ABR), WMA, WAV, ADPCM, and the emerging audio formats AAC, ASF, and OGG.

Before introducing various digital audio formats, let’s clarify one concept: bitrate.

In the field of computing, all information is digitized. Bit is the smallest unit of data in a computer, it refers to a number of 0 or 1, which is a mathematical binary number, a “0” or “1” , is a bit. For example, when we say a 2-digit number, it means that it is a two-digit binary number, and there are 4 combinations of “00”, “01”, “10” and “11”, which represent 0, 1, 2 and 3 is four numbers.

320 kbps audio bit rate, ideal for streaming.

320 kbps audio bit rate, ideal for streaming.

The triumphant march of the MPEG-1 Layer 3 audio recording format (colloquially called MP3) is explained by the fact that a simple and effective method of compressing an audio file was proposed, allowing to store up to 12 hours of quality music acceptable on a standard CD-ROM disc.

320 KBPS Bit Rate

Simply put, the MPEG-1 Layer 3 algorithm is based on the so-called “psychoacoustic” compression method, when frequencies and loudness levels that are not perceptible to the ear are excluded from the sounds in the spectrum. The spectrum “cleaned” in this way is divided into separate blocks (frames) of the same duration and compressed according to specified requirements. When played back, the signal is formed from a sequence of decoded frames.

The compression ratio depends on the parameters of the audio stream, which must be output after decoding the file.

The main parameter that determines the sound quality and the degree of compression is the so-called (what is) bit rate, the bandwidth measured in bits per second.

The higher the number, the better the sound quality and the lower the compression ratio. Since almost all MP3 files are recorded in stereo with a 44 kHz encoding rate and 16-bit depth, the determining factors for clear sound are: the source of the recording, the codec used, and the selected bit rate. .

The word codec is formed by combining the words encoder + decoder. This is a software module that allows you to encode or decode audio or video files according to your own algorithm.

The average value of the stream of 256 kbps provides a compression ratio of approximately 6: 1, for other values, the compression ratio changes proportionally. So, with 256Kbps stream, you can record music from six regular audio CDs to one CD, and with 128Kbps stream, you can record from twelve regular music discs.

There is a never-ending controversy between amateurs and professionals about the bit rate that provides good sound quality that matches the playback quality of an audio CD.

Some consider the level of 128 Kbps sufficient, others are satisfied only with the maximum value of the transmission: 320 Kbps. In all probability, both are right: the only difference is what is recorded and under what conditions it is played.

The bit rate at which digitized audio was encoded is usually indicated on the CD cover. For example, the entire Beatles collection can be purchased on three 128Kbps discs or six 256Kbps discs.

It is clear that in the second case the purchase price will be twice as expensive, but the quality is also better.

If the music is played in a home car, the 192Kbps transmission will provide sufficient sound quality, the best that you still won’t hear due to the strange noise. For listening on a computer or standalone player (MP3 player), a 256 Kbps stream is accepted.

But if the signal is sent unchanged to an external device and output to high-quality speakers, the maximum possible stream is desirable: 320 Kbps. Based on the above considerations, a stream of 256 Kbps can be considered universal: with a good recording quality, it will provide adequate playback in most cases.

INFLUENCE OF THE BIT RATE ON THE SOUND QUALITY OF AN MP3 FILE

INFLUENCE OF THE BIT RATE ON THE SOUND QUALITY OF AN MP3 FILE

Bit Rate

The term bit rate means how much information was transmitted per unit of time. Encoding in MP3 files can be done with constant and variable bitrate. Usually it determines the sound quality and consequently the file size.

BIT RATE

In normal practice, the bit rate for high-quality recording starts at 128 kbps. Although this is a purely subjective opinion and for everyone it can have its own value. It is undeniable that the higher the bit rate, the better the sound quality.

At a value of 320 kbps, the sound of an MP3 file is already difficult to distinguish from the original by the human ear.
The following table shows the comparative characteristics of the sound quality of a certain bitrate value with equivalents that are understandable to everyone. Although, we repeat, this is a subjective opinion.

Bitrate value comparison:

Bitrate (kbps) —– Mono / Stereo Equivalent
8 mono —– Telephone conversation
16 mono —– shortwave radio
32 monkey
—– Medium Wave Radio 64 Stereo FM Radio
96 stereo —– Nearly CD quality
128 stereo —– CD quality

Now let’s try to do a little quality comparative analysis of MP3 files of a certain bit rate with originals:
• 112 kbps: the sound is unnatural, the sound is far from the original. Almost any listener will notice the difference. Encoding with these parameters is ideal for listening to melodies through mobile phones (although progress has come a long way and 112 kbps is no longer sufficient on some devices). It is also very attractive for broadcasting live broadcasts over long distances.
• 128 kbit / s: many manufacturers consider this value as the standard for encoding (this is highly debatable). The quality is more or less acceptable here. Many music lovers will note that the recording is not original. Although, thanks to the many “manufacturers” of CDs, users will soon accept this quality as a source. The records can be comfortably listened to on jarring plastic office speakers, cheap headphones and iPods, and of course cell phones. If you need to recode this recording to WAV format, you will lose your sense of taste forever.
• 160 kbps – here the situation is much better than before. Many will no longer understand the difference, and those who notice slight discrepancies with the original, put 192 kbps. This bit rate suits you 100%.
• 256 or 360 kbps: For many people it will be impossible to tell the difference in sound. Recommended for fans of high quality sound, owners of hi-fi equipment, large flash players, etc.

In the following table, we will consider the effect of bitrate size on the amount of disk space occupied and the number of files that can be placed on a certain amount of media. As a comparative value, we take a sound file with a duration of four minutes, which corresponds to the average composition.
This table does not include heavier discs like DVD or the latest standards like HD DVD and Blu-Ray. But even from the last column, you can imagine how much information, even with the best quality, can be put into the new media formats.
File and disk size dependency on bit rate
Bit rate (kbit / s) 4 minute files in 64MB RAM 4 minute files on CD (650MB) Hours on CD (650MB) 4 minute files on 1GB
64 34355 24543
80 28 284 19 437
96 22237 16364128
18177
12273160
14142 9218192 12118
8182256 8 89 6137

Perhaps the greatest amount of software has been written for the MP3 format.
Not a single self-respecting software player developer, and even home gamers, will dare today not to provide support for the famous format for their creation. He’s at the top of his form, experiencing a real boom. All computers likely contain files of this type, while others have thousands of them (downloaded from the Internet or copied from discs). People are buying turntables that have become outrageously cheaper. Stores are packed with MP3-tagged CDs. People already know this word as “CD” before.
However, despite all this apparent lack of clouds, the format also has disadvantages. This is imperfect stereo encoding, problems with gapped files, multi-channel sound, high frequencies and others. Many formats are already on their heels. This is the ubiquitous Microsoft with its WM A, OGG Vorbis and others.
But the most competitive now is probably the AAC format, which Apple actively and successfully supports and promotes on its iPods and the iTunes Internet service. There is also support from Dolby, Nokia (on new phones) and many other companies.

MP3: the ideal sampling frequency according to each use.

With MP3 and other audio formats, it is important to use the same sample rate from recording to playback whenever possible. While you can convert the sample rate at any time, sample rate converters almost always produce artifacts. The following sample rates are ideal for various applications:
To convert music CDs to MP3, for example, using our media player instructions, it is better to use the original 44100 Hz sample rate.

Mp3 Bitrate

DVD and BluRay sound is generally stored and played at 48,000 samples per second. So here you should stick to the 48 kHz sample rate. When converting 96 kHz audio to MP3, 48 kHz often sounds better than 44.1 kHz.

For pure voice recordings using a sound recorder or other software, a sampling rate of 8 to 9 kHz is sufficient, since small microphones above 4 to 5 kHz contain little sound energy.

If the sound quality of radio plays and audiobooks is not that important to you, because you want to carry as many stories as possible on an MP3 player, for example, use a sampling rate of 22050 Hz, although it is quite low. With half the sample rate, you can also cut the MP3 bit rate in half without losing quality.
If you digitize your old cassettes, 32 kHz was sufficient as the sample rate, because the tapes barely register frequencies above 16 kHz anyway. In other words, it would be unnecessary to use a higher sample rate.

What is the sample rate?

It is the speed with which “photographs” are taken (actually samples, in this case sound) and the more they are taken per second, the higher quality will be obtained. Think that the sound is represented by curves, and a curve will draw better the more detail or more dots it contains. It is impossible to represent well a curve with 3 segments, even with 10. The more segments it has, the more faithful it will be and the more similar it is to the original.

Because the quality is exactly that: how similar is the encoding to the original version. And there are two factors that count a lot: Sample rate and bitrate. Of course, the higher the sample rate and the higher the bitrate we will find a greater utilization of the disk space, which at this point is not usually a priority.

The size it occupies on the hard disk

Recall that the mp3 emerged precisely as a solution to save space on the hard disk. It was unmanageable to pretend to have a large music collection in WAV format (original format, without compression) on one of those small hard drives from a few years ago.

On the other hand, trying to download a complete WAV of a song from the internet or transfer it from one computer to another was also unmanageable, since they took up too much disk space.

Then the mp3 and later all the other compression formats, sought to achieve a good audio quality occupying perhaps 10 times the space that a WAV occupied.

WHAT IS THE NORMAL BITS SPEED ON AN MP3?

BIT RATE

The bit rate of an MP3 indicates the density of the audio information contained in the file. Therefore, every second on a 192 kbps MP3 contains 192 kilobits (24 bytes) of data. The higher the bit rate, the more information the MP3 contains; The more information it contains, the quality will be closer to the original audio recording. The bit rate also determines the size of the MP3 file: a four-minute song encoded at 128 kbps takes up just over 3.5 MB, while the same song encoded at 320 kbps requires more than 9 MB of space.

Bitrate

CHOOSE A BIT RATE

When converting an audio file or ripping the CD collection to MP3, you must specify the bit rate you want the encoder to use. Choose a bit rate based on the type of audio you are encoding and the desired purpose. If you are converting a conference or other piece of vocal audio, a 128 kbps bit rate is more than enough. If you encode MP3 files for use with a portable media player, a 192 kbp bitrate generally provides a good balance between audio quality and file size. If you are converting your CD collection to MP3 for archiving, encode your files with 320kbps bit rate.

Mp3 Bitrate

VARIABLE BIT SPEED

Encoding with a variable bit rate changes the MP3 bit rate based on the type of data present at a certain point in the audio. For example, a variable bit rate encoder can encode dense information from an MP3 at 320 kbps; however, when the audio contains a mute section, the encoder reduces the bit rate to 32 kbps. If the bit rate of an MP3 has an unusual number (for example 204 kbps), this indicates that the MP3 creator has encoded it with a variable bit rate.

BITS SPEED CONVERSION

Although most MP3 encoding and conversion programs can modify an MP3 with a different bit rate, this is not a good idea in general. Converting an MP3 to a higher bit rate does not add audio information to the file, so the sound quality does not increase. Converting an MP3 to a lower bit rate reduces the file size, but it could also have audio defects as the encoder is compressing an already compressed file. If you need an MP3 file to have a different bit rate, re-encode an MP3 from the original audio CD or WAV file.

Everything you wanted to ask about the mp3

WHAT IS A CODEC AND WHAT IS IT FOR?

CODEC is an abbreviation of CODifier-DECodifier, which already indicates its functions. In the case of MP3, it deals with processing the sound, applying various compression methods to reduce the size necessary for its storage, and conversely, to reconstruct the sound from the encoded information. The codecs can be found in the form of an executable file, a DLL, or less frequently, incorporated into the code of another program. The DLL format allows the same codec to be easily used by different programs, while the executable format is usually more flexible in terms of configuration, although it is more complex to use.

WHAT DOES “PSYCHOCAUSTIC COMPRESSION” MEAN?

This very complicated word refers to the main compression technique that MP3 uses (although it is not the only one), which simply consists of eliminating the information (sound, in this case) that, in theory, is not able to perceive the ear human. I say “in theory” because, depending on the compression ratio that is applied, that loss may be more or less noticeable, hence some files do not sound as good as would be desired. The different codec also do not use psychoacoustic principles in the same way, so the quality they achieve will not be the same.

DOES THE SOURCE ORIGIN INFLUENCE THE MP3 QUALITY?

Evidently. The ideal is to start from an original CD. Analog sources, such as vinyl records or tapes, have lower quality in themselves, no matter how much we “digitize” or “improve” them with some programs. Recorded CDs may contain errors (which will end up being noises when played), and we usually do not know from which source they have been recorded (perhaps from previously encoded MP3 files). Re-encoding an already compressed music file, in the same or another format, is also a mistake, since quality is always lost.

DO THE PROGRAMS WE USE TO EXTRACT AND CODIFY THE QUALITY OF MP3?

It also seems obvious, so much so that this point should not be here. But many people do not take it into account, without knowing the reasons very well.

DOES THE QUALITY OF PLAYERS INCLUDE IN THE QUALITY OF MP3?

To hear it, you already know the answer, don’t you? J. To have it stored on the hard drive or on a CD, nope. Jokes aside, and in theory, all decoders should get the same sound from an MP3 file. But unfortunately this is not the case, usually because they do not strictly conform to the MP3 standard. You can find the best explanations on this topic here.

DOES THE QUALITY OF THE SOUND CARD AND SPEAKERS INCLUDE IN THE QUALITY OF THE MP3?

Well, I think you already know where the shots are going, we will not continue along this line. But nobody says “is that MP3 does not sound good” when it has a Sound Blaster 16 (what times those!) And some 800 W TurboPowerSound speakers that cost € 18 uros.

WHAT IS BITRATE?

It is the number of bits that are used to encode a second of sound, if we talk about MP3. It is measured in Kbps (kilobits per second).

As there is often confusion, we will give an example. If we have a 4-minute MP3 encoded at 128 Kbps:

-One second occupies: 128 Kbits x (1 Byte / 8 bits) = 16 KBytes.

-The complete song: 16 KBytes / second x (4 minutes x 60 seconds / 1 minute) = 3840 KBytes = 3.75 MBytes.

The formulas could be more correct, but this is not a mathematical thesis and I think they are enough to understand us.

WHAT DOES CBR, VBR and ABR MEANS, AND WHAT IS THE DIFFERENCE?

They are different coding methods. CBR means “Constant BitRate”, VBR “Variable BitRate” and ABR “Average BitRate”. It is easy to deduce that if CBR is used, the bitrate remains fixed, and if VBR is used, the bitrate changes. ABR can be considered a variant of VBR in which the objective is to achieve a certain final size, since we can set the average bitrate to be used (although it will never be as accurate as CBR).

The great advantage of VBR is that it uses more bits when the fragment to be encoded is more complex, and less when there are silences or it is simpler, so that we will achieve the highest quality using the minimum possible space. If the final size is not the deciding factor, it is the most recommended option.

WHAT IS THE BEST MP3 CODEC TO COMPRESS MUSIC? WHAT IS YOUR BEST CONFIGURATION?

The first question is easy to answer: LAME. In many different tests, done independently and with means that probably none of us will ever have, LAME is considered again and again as the best codec. And since there is no commercial motivation, since it is free distribution software, we can give full validity to these tests. The Fraunhofer codec and some of its “versions” could be valid in certain circumstances, but … do we need to use a commercial or pirate codec with a free and legal substitute? I think not (and from here, what each one does, is his own thing). For me, codec MP3 = LAME.

The second question is much harder to answer. There is no configuration that is perfect for everything (because if not, the modifiable options would be left over and everything would be much easier) J. But there are some recommended options in general, which we can establish with the assurance that the result will be of good quality. I have to admit that I barely change them, but as in this case (and in many others) there are no absolute truths, everyone has to try until they establish the one that best suits their preferences (or their ears).

The first thing that we must be clear about is that, in an MP3 file, size and quality are conflicting terms. We have to look for a practical middle ground. I put that term between 128 and 192 Kbps (some will say it is too low … I will try to justify my opinion). In principle, the purists established the CD quality at 256 kbps CBR. That is, using that bitrate, the sound of the CD and that of the MP3 file were absolutely indistinguishable. But, right now, LAME is already very developed. It uses the most advanced techniques, and manages to do perfectly things that other codecs are not able to solve properly (VBR, Joint-Stereo), which allows you to improve the quality and reduce the size.

In r3mix.net, after the corresponding tests, they have established an “ideal” configuration based on quality criteria. This configuration is so accepted, that in the latest versions of CDex, and other programs, it is already included as one of the preset configurations. But be careful: this does not mean that this is the only option, nor that it will always achieve the highest possible quality. Another thing is that using this option our ear can differentiate the results of the original audio CD, and this is where the “trick” of MP3 compression is.

After having used this configuration, I have observed that, although there are important variations, the average of the files is about 170-175 kbps, and that they rarely go beyond those 192 Kbps that I mentioned before, so I consider that overcoming that bitrate does not it will hardly improve the quality, but it will significantly increase the size. Although I repeat, there will always be someone to whom this bitrate seems insufficient, and will use even 320 Kbps, which is the maximum supported by LAME.

The second part is to take into account the equipment we have. If the MP3s are not going to sound through a card, an amplifier and very good quality speakers, the bitrate can be adjusted a little more without practically noticing variation in quality. The average 160 Kbps seems like a very reasonable amount to me, and that’s how I usually code my CDs. And I can say that they don’t sound bad at all. If someone is able to do a “blind” test and differentiate between several files encoded (correctly) at 160 and 192 Kbps, you really have to congratulate him on his ear.

Finally, if we consider size as a decisive factor, we could go down to 128 Kbps, but considering that the quality may already be too compromised. Summarizing:

Configuration that seems more appropriate for practical purposes, and looking for a high quality (about 192 Kbps):

-Joint-Stereo -> Get reduce the final size without losing quality. Sometimes, where there is a lot of variation between channels and with high bitrates, it could be configured as Stereo.

-VBR MTRH Quality 1 or R3Mix Preset -> Change the bitrrate according to the needs of each moment, improving the quality without increasing the size with respect to CBR (normally).

-Bitrate minimum 64 Kbps -> To compress to the maximum silences and very simple fragments.

-Bitrate maximum 256 Kbps -> So you have room to improve the quality in complicated fragments.