Sampling of amplitude change over time and continuous signal in a certain time interval to take out the sample value, form discrete pulse sequence in time, is called sampling.
The time interval is called sampling cycle, for Ts, the corresponding sampling frequency fs = 1 / Ts.
Quantify the amplitude of the analog signal dynamic range is divided into several levels of equal interval, the sampling of the output signal level, according to the principle of rounding into closest to the value, called quantitative.
Coding the sampling, quantify the magnitude of the transformation as a binary digital process known as encoding.
In digital audio, usually adopts 16-bit (
Digital said a quantity, namely the quantization digit n = 16.
Error correction coding with CD and cassette tape in production and in use process will happen than allowable range of damage, read by digital signal recorded with the original signal is different, therefore, must adopt measures to correct the wrong words. if.
Modulation analog audio signal sampling, quantization, coding and the CIRC error-correcting codes after the formation of the digital signal, also should not be directly recorded on the disc or tape.
Because all 16 May arise in the data stream to 0 or 1, reading from the CD or tape to signal is unstable, and will cause the servo system unstable.
Frame structure is digital signal a character, if the offset one, would make it represent the character of the signal level change.
Therefore, must be the recorded signal is divided into small block, and try to determine the dividing line between each word group, such word group is called a frame.