The core hardware circuit for digitizing audio signals is the A/D converter, that is, the audio codec. The function of A/D conversion is to convert analog quantities that are continuous in time and continuous in amplitude into digital signals that are discrete in time and discrete in amplitude.
The operating environment of this tutorial: Windows 7 system, Dell G3 computer.
The core hardware circuit for digitizing audio signals is the A/D converter, that is, the audio codec.
The function of A/D conversion is to convert analog quantities that are continuous in time and continuous in amplitude into digital signals that are discrete in time and discrete in amplitude. Therefore, A/D conversion generally requires sampling, holding, Quantization and coding are four processes. The D/A (digital/analog) converter converts the analog audio signal into a digital signal at the encoding end, and the decoding end converts the read digital audio information into an analog audio signal output for power amplification and playback.
Extended information:
The digitization of signals is to convert continuously changing analog signals into discrete digital signals. Generally, three steps of sampling, quantization and encoding are required.
Sampling - refers to using a sequence of signal sample values at certain time intervals to replace the original signal that is continuous in time, that is, discretizing the analog signal in time.
Quantization - is to use a limited number of approximations to the original continuously changing amplitude values to change the continuous amplitude of the analog signal into a limited number of discrete values with certain intervals.
Coding——According to certain rules, the quantized discrete values are represented by binary numbers.
The audio signal processing system consists of audio recording and playback head components, audio recording circuits, audio playback circuits and corresponding interfaces. Because the frequency bandwidth of audio signals is much lower than that of video signals, and the principle of audio signal processing is the same as that of a tape recorder.
Therefore, the audio recording and playback head also adopts a fixed playback type that works on the same principle as the tape recorder. When the tape moves stably and passes across the head, the audio signal is recorded on one edge of the tape.
In order to improve the amplitude-frequency characteristics of the audio signal to achieve high-quality audio recording and playback, some video recorders will also use the same design as the video head, setting the audio head on the drum and rotating accordingly.
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