[Audio]
The voice frequency that the human ears can hear is 20Hz ~ 20 kHz
SonicIt is called audio.
[Sampling frequency]
That is, the sampling frequency, which refers
Number of times a sound sample is obtained per second. The higher the sampling frequency, the better the sound quality, and the more authentic the sound is, but at the same time it occupies more resources. Because the resolution of human ears is very limited, it cannot be determined at a too high frequency.
The sampling frequency of 22050 is commonly used, and the sampling frequency of 44100 is CD sound quality. Sampling of over 48000 or 96000 is meaningless to human ears. This is similar to the principle of 24 frames per second in a movie.
If it is a dual-channel (STEREO), the sampling is dual, and the file size is almost doubled.
[Number of sampling digits]
That is
Sample ValueOr sample value (that is, quantize the sample range ). It is a parameter used to measure the fluctuation of sound, or the resolution of the sound card. The larger the value, the higher the resolution, and the stronger the sound.
Each sampling data records the amplitude, and the sampling accuracy depends on the size of the number of sampling digits:
- 1 byte (that is, 8 bit) can only record 256 numbers, that is, it can only divide the amplitude into 256 levels;
- 2 bytes (that is, 16 bit) can be subdivided into 65536 numbers, which is now the CD standard;
- 4 bytes (that is, 32 bit) can segment the amplitude to 4294967296 levels, which is unnecessary.
[Number of channels]
That is
Number of sound channels. A single sound channel and a stereo sound are often divided. A single sound channel can only use one speaker to generate a sound. (Some also process two speakers to output the same sound channel ), stereo Sound can make both speakers speak out (generally there is a division of labor in the left and right audio channels), better space effect, of course there are more channels.
[Frame]
Frame records
Sound UnitThe length is the product of the sample length (number of sampling digits) and the number of channels.
[Cycle]
Audio Device
Number of frames required for one ProcessingThis is the unit for data access from audio devices and storage of audio data.
[Staggered mode]
Digital Audio Signal storage method. Data
Sequential frame storageFirst, record the left and right channels of frame 1, and then start the record of Frame 2...
[Non-staggered mode]
The first record is the left-channel sample of all frames within a cycle, and then all right-channel samples are recorded.
Bit Rate]
Transmission Rate per second(Bit rate, also called bit rate ). For example, 705.6 kbps or 705600bps, where B is bit, PS means the capacity of 705600bit per second.
