In the field of audio and video, people are always pursuing unlimited restoration of live effects, so the more realistic the audio, the better, and the clearer the video, the better. The reason why we need to convert audio and video signals from analog to digital is to avoid distortion in recording, storage, editing, copying, playback, etc., to maintain the original details as much as possible, and not to reduce the quality of audio and video due to the above operations.
For this reason, the resolution of video systems is getting higher and higher, and high-definition 1080P is not enough. 4K, 6K, 8K... have appeared, and the frame rate has also ranged from 30 frames per second to 60, 120...; audio is also increasingly pursuing multi-sound. channel (mono, two-channel, 2.1, 5.1, 7.1...), lossless compression, etc.
Converting audio signals from analog to digital involves the following concepts:
- Sampling: Measure changes in analog signals at certain time intervals.
- Quantification: The measurement results obtained by sampling are described numerically according to certain standards.
- Sampling rate: How many times per second, in kilohertz (kHz). The higher the value, the closer it is to the original analog signal, the richer the details, the larger the amount of data, and the larger the file size.
- Quantization depth: the number of binary digits used to describe signal changes, the unit is bit. The higher the value, the richer the detail... (same sampling rate)
- Encoding: The data obtained is stored in what format.