From Analogue and Digital
When We convert an analog signal into a digital code, it is necessary to perform three next processing. ① Sampling ② Quantization ③ Encoding ①Sampling Sampling is dividing the analog data that is consecutive data by a unit for period of time and processing to extract a signal level every that time as a specimen. We convert temporal axes into the digital data with the stage from consecutive analog data without the stage. ②Quantization We establish whether we express a signal level with several phases. Then, we apply the data which we sampled to a number for the stage and replace it with an integer value. This processing is the quantization of the signal. ③Encoding I convert data into binary of 0 and 1 by our encoding the integer value that I used by quantization. We can classify the methods of the encoding in two kinds mainly. It is called codec to convert a sound into digital by encoding.