How to distinguish the sound quality of Mp3 songs?


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How to distinguish the sound quality of Mp3 songs?

Mp3 quality

Factors that affect audio quality are the number of channels, the sampling rate, and the number of quantization bits.

Mp3 Quality

It’s not directly related to file size, I think friends who have used Audition or play more music will be more familiar with it.

-Number of channels

Channel count is easy to understand and is often referred to as channel count. Usually we talk about left and right channels, single and double channels, which refers to the number of channels.

The music that we listen to often in life is basically two-channel, that is, the left and right channels. Generally speaking, the higher the number of channels, the better the audio quality. Then the stereoscopic feeling of the sound will be stronger. It will feel more real. When a person speaks or an object makes a sound, the sound also spreads in all directions, and of course there are more than two channels. So, in fact, it is difficult for digital audio to achieve real sound realism.

-Sampling frequency

For example, when Audition exports audio files, there is a sample rate option. What exactly is this sample rate?

Sampling rate is explained in official words: the number of samples per unit of time (within 1S). The higher the sample rate, the more data it collects and the better the sound quality.

But you will find that music in real life is generally 44100HZ sampling rate, like the lossless music in the picture above. So there are so many miscellaneous sample rate options in the image below. What does this mean? The reason is that the audible sound range of the human ear is between 20 and 20,000 Hz. Even if you increase the sample rate, it will still sound the same to ordinary people, so there is no need.

-Quantization bits

This is also very understandable. It’s like the number of bits that people often say about the computer. Audio also has the concept of bits. A common number of bits for audio is 16 bits. Generally speaking, the higher the number of bits, the better the sound quality. The popular understanding of quantization is to digitize the sampled value, that is, in the binary form recognized by the computer.

The property display in Windows may not display these parameters intuitively, but you can see them with the help of tools. Sound quality is determined by the above three aspects. Instead of looking at the size of the file. Of course, the audio is basically compressed and transcoded when it is broadcast to the audience. After all, high volume digital audio is not conducive to broadcasting.

 

FAQ

How to distinguish the sound quality of an mp3?

It is important to look at several elements to distinguish its sound quality. Of course, first is the quality of the recording, then the bitrate and samplerate.

Your can improve the sound quality of an mp3?

It is possible, using Mp4Gain, to improve the perception of the quality of an mp3 or any other audio or video format. In addition to modifying the bitrate and sample rate, we can modify the “color” with an equalizer and even slightly modify the pitch and of course normalize the audio.


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MP3: quality standard?

For many, dematerialized music rhymes with illegally downloaded MP3.

If this comment is often true, since illegal music sharing platforms have made mp3 the primary format for music playback, you obviously need not limit yourself to the single mp3 format.

Mp3

MP3: birth of a format

The MP3 was democratized on the music exchange platforms of the time like Napster, Kazaa, Emule … in the late 90’s and for good reason they allowed you to download an entire album in a few minutes by compressing the music and thus shrinking the files.

Therefore, it is the need to exchange files and shorten the download time (remember we were paying the internet at that time according to your connection time …) making the development of mp3 essential and for many synonymous with dematerialized music.

The MP3 principle is therefore simple and attractive on paper: enable file sharing by drastically reducing the weight of files (more than 90%), and only by keeping what the human ear can do. listen, that is, the frequencies between 20 Hz and 20 kHz.

MP3: bad reputation

Unfortunately, the main consequence of this thin race is that the quality deteriorates: every mp3 has a compression level. The higher it is, the more the musical signal is cut off: this is called destructive compression: we eliminate all information that is considered useless and impossible to return.

Mp3

Therefore, during this period there was the spread of the famous 128 kbps MP3: this figure indicates the amount of information in the file and therefore its quality, the higher and better the sound will be. Therefore, some sort of standard has gradually been established around this bit rate of 128 kbps (kilobits per second), since it is inseparable as the quality of the CD at 1411 kbps.

mp3 – Napster

The Napster interface, one of the first illegal music sharing programs. Note the music ratio at 128 kbps (see less …)

It is clear that we do not reduce the amount of musical information by 90% with impunity and the results are often poor, the quality of the mp3 with 128 kbps is much lower and perfectly noticeable from the original CD. Then the new bit rates of 160 kbps, 192 kbps, 256 kbps and 320 kbps came to maximum, then “VBR” formats for “Variable Bit Rate” and against CBR (constant bit rate)) used earlier: we decreased the bit rate at rest and increased if necessary.

Therefore, we can see that it is difficult to pronounce the MP3 format in general: the results will be very different between a 128 kbps CBR mp3 and a 320 kbps VBR and, to a large extent, for the latter, for the price of one double weight.

Alternatives to MP3

MP3 is not the only dematerialized music format, it is first necessary to divide the compression formats into two categories:

Destructive Compression Formats: We remove content to reduce its size

MP3: the readable standard for 100% of music devices released in 20 years

AAC: Used by Apple in the iTunes music store (Apple Audio Codec), almost as universal as MP3

Ogg Vorbis: a free, efficient yet non-standard format

WMA: Microsoft format, not very standard either, except on Windows PC (can Microsoft have anything to do with it?)

Non-destructive compression formats: we compress the data for storage and decompress it when reading, therefore the sound reproduction is lossless, but it generates files 3 times larger:

FLAC: Free Lossless Audio Codec, it is somewhat the equivalent of Ogg in that it is royalty free and has established itself as the current standard for non-destructive formats (lossless in English)

ALAC: The Apple version of FLAC, which has also been in free form for some time, has the advantage of being compatible with the brand’s products and computers and offers the same benefits as FLAC.

Mp3: Advantages of MP3

MP3 refers to an encoding format that is formally referred to as MPEG-1 Audio Layer III for digital audio. Designated MP3 or MP3 data that stores basic MPEG-2 audio data or MPEG-1 audio data that is encoded. They do not contain any completely different complexity than the format. Find out more about the MP3 file format and its benefits.

As worrying as audio compression is, MP3 is a lossy compression module for encoding data with the expectation of partial rejection and inaccurate approximations of the data. And this ends with a noticeable reduction in file size, now no longer like with uncompressed audio.

The small size and excellent audio quality led to the provision of song data on Highway Records in the 1990s. MP3 served as expanded storage capacity and bandwidth in these hardly expensive times.

In about a year, the MP3 format has addressed controversy surrounding song piracy and copyright infringement. Instead, this file format became a custom format with the advent of avid portable gamers, including smartphones.

How does this compression work? This compression reduces the precision of the explicit parts of the sound that people can no longer hear. This method is ceaselessly referred to as perceptual coding or psychoacoustic modeling.

Then the free time of audio knowledge is recorded with the extraction of the allocated memory. FFT and MDCT algorithms are used here. Unlike CD audio, this audio compression design can reduce file size by up to 95%. Every time you document a conversion at a fixed bit rate of 128 kb / s, the file size is 9% more realistic than the audio on the actual CD.

Advantages of MP3

Here’s a hint about one of the benefits the MP3 audio file format offers. For these benefits, you can also lift whenever you can safely move around in this format, or opt for a lossless option.

One of the main advantages of this file format is that you can document songs, speeches or conversations for hours without affecting the allocated storage space. Basically, up to 95% of the allocated storage space is allocated. And the most important thing is that fine audio is identical with completely different codecs that take a lot of assignment.

The small size of such audio data allows you to map hundreds of data onto a small memory card or memory card. In other words, you can also save more than 170 songs on a CD with a storage capacity of 700 MB. On the other hand, the CDDA option does not mean that more than 15 tracks can be saved.

Instead, due to the logic that the file size is extremely small, you don’t have to spend a lot of bandwidth every time you get a lot of songs. Therefore, MP3 is a great wish for all types of users.

The best thing about MP3 is that you can change the audio level you want based on the available memory allocation. It can also rise between 32 kbps and 320 kbps. On the other hand, indicate that the higher the bit price, the larger the file size.

Audio quality: Bitrate in MP3 files

In many cases the term Bitrate is used, which is the bit rate per second that a multimedia file (Audio or Video) has. Currently the MP3 music format is one of the most widespread (Although there are currently other more current formats such as OGG Vorbis, AAC, Flac, Monkey Audio, …) however the audio quality is variable, this is due to the characteristics with which the MP3 in question has been compressed, including:

Mode: It can be of two types mainly:
Mono: With a single channel (The right and left channel go together, not separated which gives worse audio quality).
Stereo: Two channels (Right and Left, improve audio quality).

Sampling frequency: Audio CDs use 44,100 Hz (22,050 Hz per channel), although there are higher frequencies such as 48,000 Hz used in DVDs and lower, the higher the frequency, the higher the quality.

Bits: Audio CDs have 16 Bits (Although MP3 can be compressed at a lower quality such as 8 Bits).

Bitrate (Bit Rate per second): Audio CDs have about 1,400 Kbps (44100 Hz * 16 Bits * 2 channels), meaning that an Audio CD would have a bitrate of 1,400 Kbps (In MP3 format the maximum Bitrate is 320 Kbps, however, it is assumed that an MP3 with a 128 Kbps Bitrate has a quality similar to CD, although in many cases to achieve a quality similar to CD it is necessary to use a Bitrate of 192 Kbps, and to obtain CD quality it is necessary use 256 Kbps or 320 Kbps).

Some of the most common Bitrates are:
8 Kbps Mono: Telephone Sound.
16 Kbps Mono: Better quality than shortwave.
32 Kbps Mono: Better quality than AM.
64 Kbps Stereo: Better quality than FM.
112 – 128 Kbps: Quality close to CD.
160 Kbps: Quality closer to CD.
192 Kbps: Virtually CD quality.
256 Kbps: Quality CD practically undisputed from an original CD.
320 Kbps: CD quality.

Coding method: It can be of two types:
VBR (Variable Bit Rate, Bit Rate Variable): Encodes the file in MP3 with a variable Bitrate.
CBR (Constant Bit Rate, Constant Bit Rate): Encodes the MP3 file with a fixed Bitrate.
In addition, another factor that influences the encoding of the MP3 file is the CODEC (Encoder-Decoder) used, one of the most common and the best result is LAME (Lame Ain’t an MP3 Encoder) which is also free.
One point to keep in mind is that if we recompress an MP3 file that originally has a 128 Kbps bitrate and convert them to 192 Kbps for example, audio quality is not really gained because the MP3 format has some quality loss (MP3 is a loss algorithm, also called lossy). which has occurred when converting the original file (Ex: CD Audio or a 320 Kbps MP3 to a 128 Kbps MP3) so this recompression does not make much sense since we will not gain in audio quality (As they say where there is no one can not get) and the only thing we will achieve in any case is to increase the initial size of the file.
The opposite case (Recompress a 320 Kbps MP3 file for example at 192 Kbps) if it makes some sense because in this case although we lose some audio quality we reduce the weight (Kilobytes or Megabytes) of each MP3 file somewhat.
In conclusion, it can be said that if we need to encode / compress an MP3 file with good quality, the “ideal” would be to do so:
To be able to start from an Audio CD, although an MP3 at 320 or 256 Kbps could also be valid for a recompression of the file.
In stereo mode (With two channels, right and left).
With at least 44100 Khz sampling rate and 16 Bits.
With a minimum bitrate of 192 Kbps or at most 256 Kbps (Using 320 Kbps would give higher quality but also increase the file size considerably).