What is lossless?
In June 2021, Apple Music lifted the ban on hi-res and lossless, with “lossless” attracting attention.
Do you correctly understand the meaning of the word “lossless” when looking at this page? What does “lossless” mean here? Higashihara, a new editor, had doubts about the meaning and sound quality of the word “lossless”, so I did some serious research. We also have a sound source that you can download for free, so let’s get to know each other while listening to them.
sound quality
Sound source data equivalent to a lossless CD sound source (16-bit/44.1 kHz). There are uncompressed sound sources and lossless compressed sound sources that can be compressed and stored without deterioration. In the sense that there is no “loss” due to compression (less), CD sound quality data is generally referred to as such.
Sound source data with a quantization bit rate/sampling frequency (24 bit/44.1 kHz or higher) that exceeds Hi-Res CD sound source (16 bit/44.1 kHz). For that amount, the capacity will be larger than the CD sound quality sound source data, but since the data can express more delicate expressions, a deeper sound can be heard.
● Click here for a more detailed explanation of the above high resolution.
■ The sound quality is
sound and voice quality. Sound has the following three aspects, and sound quality is determined by exerting these properties on each other.
1. Aspects such as physical signs
2. Aspects of auditory psychoacoustics of hearing humans
3. Aspects of expression expressed by a collection of sounds such as voice and music
Also, the following three units are important for measuring sound quality. ..
(1) bit (quantization bit number)
A value that shows how precisely the intensity of the sound can be expressed (large and small). The lower the number, the smaller the sound will be recognized as noise, and the higher the number, the more detailed the sound will be reproduced.
(2) kHz (sampling frequency)
A value indicating how many times per second the original sound is sampled (sampled) when digitizing. The greater the number of samples (the larger the value), the finer the data can be.
③ Bit rate
Abbreviation for bit per second. A value indicating how much data was transferred per second when sending and receiving data. If the pulse rate is high, a lot of data can be transferred and smooth data can be received, and if it is low, little data can be transferred and the data will be interrupted.
compression performance
Reversible compression sound source ⇒ Representative form な: ALAC, FLAC
Lossless compressed sound source diagram
* This diagram shows the quality of the sound when it is compressed and then uncompressed.
A data format that reproduces the quality of the original sound by reducing the storage capacity (compression) of the sound source data according to the rules of each format (codec) and expanding it according to the playback rules. It has less capacity than the uncompressed format, but it cannot reduce data capacity as much as the lossy compressed format. Since data capacity can be reduced without degrading sound quality, this compression format is often used when dealing with lossless (CD-equivalent sound quality) and high-resolution sound sources.
Uncompressed sound source ⇒ Typical format: WAV, AIFF
Uncompressed sound source diagram
The original data format of CD sound quality (16 bit/44.1 kHz) and high resolution (24 bit/44 kHz or higher). You can of course listen to the sound quality as it is. In the old days, the amount of data was said to be relatively large depending on the compressed sound source, but that was 20 years ago too.
