Personally, I think that for people with average hearing, listening to music with lossy compression formats such as mp3 and wma can't be distinguished from lossless music. So, listen to mp3!
However, the sampling rate of mp3 music should be higher.
Other professional reference materials:
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MP3 file
MP3 format is the most widely known and used by the most users at present, and it is also the most popular music text on the Internet.
Most of them are also in MP3 format. The full name of MP3 is MPEG Audio Lay-3, which belongs to MPEG- 1.
Level. It was born in 1993, and its "parents" are Faunhofe IIS in Germany and Tom in France.
Thomson company. MP3 uses the compression ratio of 1: 10 or even 1: 12 to change the sound to a lower volume.
File, but to the human ear, there is no difference. Of course, this is a kind of distortion compression, just like
Like the graphic file JPG, because of distortion compression, it can be pressed a lot and the compression ratio can be adjusted.
The greater the pressure, the more serious the distortion. Do you doubt the quality after distortion? As long as the compression ratio is not too exaggerated.
Rate, the human ear is indistinguishable, just like a JPG file, don't compress it too much, it is difficult for the human eye to distinguish it.
Get out. The early MP3 coding technology was not perfect. For a long time, most people survived.
The MP3 file is encoded in the CBR (fixed coding rate) format of 128Kbps until VBR (variable coding).
Code rate) and ABR (average coding rate) compression modes appear, which can reach the highest coding bit rate.
320Kbps, MP3 files began to improve in sound quality, and the appearance of the lame is such progress.
Brought a qualitative leap.
WMA
WMA is the abbreviation of Windows Media Audio, which is a digital music format introduced by Microsoft. Microsoft official statement
According to the data of cloth, WMA format is very protective, and it can even limit the playing machine and playing time.
And has considerable copyright protection capability. It should be said that the launch of WMA is aimed at
The disadvantage of MP3 is that there is no copyright restriction-ordinary users may welcome this format, but as copyright,
For the owner's record company, they prefer music compression technology that is difficult to copy, while Microsoft's.
WMA has taken care of the needs of these record companies, and it is foreseeable that the record industry may fully support them.
WMA standard newspaper. In addition to copyright protection, WMA has also deepened the compression ratio, with the following objectives
Under the same sound quality, the file size can be smaller (of course, provided that MP3 is lower than 192Kbps).
In fact, when using LAME algorithm to compress MP3 format, it is common that it is higher than 192Kbps.
The reflection is that the sound quality of MP3 is better than WMA). At low traffic, MP3 is not as good as WMA.
Well, it can even reach half a degree. WMA at 64kbps is indeed better than that after waveform recovery.
128kbps MP3, because low-flow MP3 discarded too much high-frequency information when encoding, but
Is it above 128? The situation has been greatly reversed, the quality of MP3 is gradually rising, and WMA is in a state of high traffic.
I can hardly get any improvement in quality, but the number of files has increased dramatically, 127kbps.
WMA is no match for 256kbpsMP3 at all. As for the traffic of 96kbps, the sound quality is better than that of CD.
However, at the sampling rate of 48Khz, the performance of WMA is not particularly satisfactory. Advantages of WMA
The potential lies in low traffic, excellent "streaming" performance and good copyright protection performance. As for the problem of high sound quality,
The problem is not particularly mature.
WMAVB(MP3VB)
The full name of VBR is variable bit rate, which is dynamic bit rate. Different from the traditional CBR coding, the traditional
CBR(Constents Bit Rate) is the static bit rate and the agreed sampling rate is a fixed value. a song
Songs are compressed from beginning to end with a fixed value such as128kbit/s. VBR adopts a brand-new and all-round approach.
Compression method of process dynamic adjustment technology. When the bass is divided, VBR will automatically adopt a lower bit rate, such as
32KBit/s compresses the sound quality, and in the high-pitched segment, it will use a higher code rate such as 224KBit/s to compress the sound quality.
Line compression, at the high end of the stage, the maximum compression is 320 kbit/s. WMAVB(MP3VB).
In the case of controlling the file size, improve the sound quality to the maximum extent.
Sound resource file
This is an ancient audio file format developed by Microsoft. WAV is a compliant file format.
PIFF； Resources; Interchange; Documents; Format specification. all
WAV has a file header, in which there are coding parameters of the audio stream. WAV coding of audio stream
There is no hard code, except PCM, almost all codes support ACM specification.
The audio stream of WAV is encoded. Many friends don't have this concept, so let's take AVI as a demonstration, because
AVI and WAV are very similar in file structure, but AVI only has one more video stream. we
There are many kinds of AVI, so we often need to install some decoders to watch some AVI.
DivX is a kind of video coding that AVI can use to compress video.
Of course, the frequency stream can also be compressed by other codes. Similarly, WAV can also use various audio codes to
Compress its audio stream, but what we often see is that WAV's audio stream is pulse code modulated, but this one is not.
It means that WAV can only use pulse code modulation, and MP3 coding can also be used for WAV and AVI.
Sample, as long as the corresponding Decode is installed, you can enjoy these wavs. On the Windows platform.
WAV based on pulse code modulation is the best audio format supported by all audio software.
Perfect support, because it can meet the higher sound quality requirements, therefore, WAV is also the creation of music editors.
Preferred format, suitable for saving music materials. Therefore, WAV based on pulse code modulation is considered as a kind of.
The format of mediation is often used to convert other codes, such as MP3 to WMA.
ape
APE is a lossless compressed audio format. Huge WAV audio files can be accessed through monkey audio.
This software was "slimmed down" and compressed into APE. Similarly, apes can also be restored to apes through the audio of monkeys.
WAV, and then burn it into a CD. Sometimes it is used for network audio file transmission because it is compressed.
The capacity of APE file is less than half of WAV source file, which can save transmission time. Prior; fore
Yes, the WAV file obtained after decompression and restoration of monkey audio can be the same as before compression.
The source files are exactly the same. So APE is called "lossless audio compression format" and Monkeys Audio is called.
Lossless audio compression software. Compared with using professional data compression software such as WinZip or WinRAR.
Unlike compressed audio files, compressed APE audio files can be played directly.
gas concrete
Audio formats, like computer software and hardware, will eventually be updated, just like tapes that have not been eliminated by CDs.
Really? CD will be replaced by DVD-Audio. As time goes on, MP3 becomes less and less full.
It meets our needs, for example, the compression rate lags behind Ogg, WMA, VQF and other formats, and the sound quality is not reasonable.
Think about it (especially at low bit rates), there are only two channels ... so Flawn Hoff and AT&T, Sony,
Dolby, Nokia and other companies have jointly developed a data compressor called "2 1 century"
Type Advanced Audio Coding (AAC) Audio Format to replace the location of MP3. in fact
The algorithm of AAC was completed in 1997, and it was called MPEG-2 AAC at that time, because it was still made.
It is an extension of MPEG-2 standard. But with the formation of MPEG-4 audio standard in 2000, MPEG-
2 AAC is also regarded as the core of its coding technology, and some new coding features have been added, so we
Also known as MPEG-4 AAC. AAC's audio algorithm far exceeds some previous compression capabilities.
Restore algorithm (such as MP3). It also supports up to 48 tracks, 15 low-frequency tracks and so on.
Sampling rate and bit rate, multi-language compatibility, higher decoding efficiency. Anyway, AAC can join in
Provide better sound quality on the premise of reducing MP3 files by 30%.
ATRAC3
ATRAC3 is an upgraded version of ATRAC compression technology, which is MD(MiniDisk Portable Walkman).
Type is also Sony's unique music compression technology. Compared with ATRAC, ATRAC3 has a higher compression ratio.
It can lossless compress music files to one tenth of the data storage space required for CD music.
Music quality. Because, in addition to retaining the original compression technology of ATRAC, we should also use human hearing.
Psychological theory. So what exactly is ATRAC? The compression format of MD is called adaptive.
Transform acoustic coding is a lossy compression format. ATRAC numbers 16 bits 44. 1KHz.
The word signal is divided into 52 parts along the frequency response axis (the low-frequency part is thinner and the high-frequency part is smaller).
Statistical analysis shows that there are many redundancies in these signals, which can be removed when coding.
So as to reduce the file size, and these redundancies can be reconstructed during decoding. And ATRAC technology is beneficial.
Psychoacoustic characteristics of human ear hearing (spectrum masking characteristics and time masking characteristics) and signal amplitude of human ear
The limited resolution of degree, frequency and time, when coding, all the components that the human ear can't feel are not coded, no.
Transmission, that is, the part that does not contribute to the human ear to distinguish the intensity, tone and orientation of the sound signal (called no
Related parts or irrelevant parts) are not encoded and transmitted. In addition to using this psycho-acoustic feature in the coding process,
ATRAC algorithm also applies it to the time-frequency segmentation process. Decoding by combining subbands
And the input signal is analyzed into non-uniform frequency points that emphasize important bass areas.
Stop. In addition, ATRAC uses a variable block length to adapt to the input signal. This can ensure that in stable communication
Outdated and efficient decoding without affecting the time resolution when the moment passes. Using this principle,
ATRAC can compress the recorded data to one-fifth of the original (that is, the compression ratio is 1: 5). in a word
To sum up, the main task of ATRAC is to compress stereo audio with 16 bits and 44. 1kHz.