First of all, popularize knowledge: the main common lossless music formats are APE, FLAC, WAV, etc. 1. The so-called lossless refers to the conversion of WAV waveform files into APE or FLAC format files. WAV is ripped directly from the CD disk, and the APE or FLAC format performs lossless compression on WAV that takes up a lot of hard disk space. As for the difference between the three, WAV is the largest, but can be played directly; APE takes up the smallest space, but takes a long time to encode/decode during playback; FLAC takes a shorter time to encode/decode than APE, but takes up a lot of space. 2. Regarding quality, for the same CD, the sound quality of APE, FLAC, and WAV is exactly the same. Don’t listen to some people’s nonsense. There are no two identical erhus in the world. If you look closely, there is a lot of difference between CD and original sound; there is also a lot of difference between WAV and CD. Even if the music data information is exactly the same, the effects of CD players and computers are also different. Playback between two CDs The same CD is also different. 3. Strictly speaking, APE and FLAC are lossless compared to WAV. In most cases, compared to CD, WAV is lossless in terms of data information, except for the incorrect grabbing method of some files, which greatly reduces the quality of the files. Closer to home, if you find that the quality of your music files is very poor, the reasons are: 1. They are lossless. This situation is seen in early CD releases and some domestic discs. Poor results due to problems with the recording equipment. 2. Fake and lossless. In this case, either the original CD is a pirated disc, or the file is transcribed from an early tape, that is, the cassette is digitized. We must resist and crack down on the former, while the latter is a helpless move because many rare resources have not been released on CD, which is a pity. 3. Fake and lossless. It's just lossy transcription from MP3, etc. What a cheater, this kind of person! It can be seen that even lossless files may not be of high quality, such as tape transcription and early CD discs; of course, most of these files are identified as non-lossless. If it is identified as non-lossless and the file is a scarce resource, it is also recommended to retain it in this case. Note that the non-destructive identification software is only an auxiliary, mainly for hearing. After all, music is for listening, not for precise scientific research. Tools/Materials Lossless Music Verification Assistant: LoselessAudioValidator Adobe Audition and other software to see the sound wave spectrum and ear listening steps/methods Choose any one of the above software (just search on Baidu to download), among which the Lossless Music Verification Assistant interface is simple to operate; Adobe Audition is more professional . In fact, the former is modified using the latter's technology and principles. Download...install...go to step 2 after installation. The lossless music verification assistant is as shown below. Click the "File" menu to select a single file, and click "Folder" to select all APE and FLAC files in a folder. When selecting files, you can select multiple files at once. Note that do not click on the boot file CUE, it is not the music itself, and the verification is meaningless. After all the files are imported into the software interface, click the "Verify" button in the menu bar to start verifying the authenticity of the lossless files. If you want to stop the verification, click the "Stop" button in the menu bar. The software will stop after the verification of the current file is completed. Just close the software at this time. If there are too many verification files and you want to delete some tasks or delete verified records, select all the files to be deleted (click on the first file, hold down the shift key with your left hand and click on the last file, so that between the two files All files between are selected), and then press the delete key. Check the verification results: Those with a check mark "√" in front of them and displayed in green are considered to be "CD sound quality", that is, true lossless; those with a question mark "?" in front of them and displayed in blue are judged to be false lossless; sometimes, individual files have a "cross" in front of them. ×” displays a verification error, indicating that the software cannot detect it. At this time, other methods of verification are needed. In the picture above, the last file is a fake APE converted from MP3. From the "Results" column, we can also clearly see the judgment results: except for the last one which shows "MPEG (indicating that it is converted from inferior MP3)", the rest are all "CDDA". From the verification result chart, we also see the "Correct Rate" column, which indicates the accuracy of the judgment result. Of course, 100% CDDA is the ideal state; in fact, as long as the result is "CDDA", it is acceptable. In most cases, the accuracy rate is between 95% and 100%.

We can also set the accuracy of the software ourselves, but it is recommended to keep the default. The setting method is as follows: Select "Options" → "Software Settings" in the menu bar, open the parameter setting panel, switch to the "Calibration" interface (as shown in the figure), and click "Calibration Accuracy Level" and "Possibility Threshold" automatically Define data. After setting, click "Save". The following is a brief introduction to the use, downloading... and installation... of the software "Adobe Audition". The Adobe Audition window interface is as follows. This software seems to only be able to detect one file at a time. Click the menu "File" → "Open", select the file to be verified and load it, as shown below: Next, click the position as shown above (if not, click "View" → "Show Spectrum"), and then get the spectrum chart below : Both spectrums are severely cut, fake and lossless, and the sound quality is very poor. For better explanation, we compare various audio files. For greater clarity, first zoom in horizontally on the spectrum. The following is the spectrum of lossless music: 320KMP3, the upper and lower spectral "one size fits all" is obvious; the lower the bit rate, the more obvious the "one size fits all". As shown in the previous figure. Notes: 1. Look at the spectrum, and lossless identification requires very careful attention. As shown in the picture below, this is a lossless 896k ape. There is basically no empty area at the top, but it is relatively sparse. The 256kbps AAC file has better sound quality: the high frequency is not as full as lossless and has some defects, but it is not a one-size-fits-all phenomenon. 2. Let’s go back to the beginning and emphasize again: even lossless files may not be of high quality, such as tape transcription and early CD discs. If it is identified as non-lossless and the file is a scarce resource, it is also recommended to retain it in this case. Software non-destructive identification is only an auxiliary, mainly for hearing. After all, music is for listening, not for precise scientific research.