我能否找到一种方法来获取音频文件（如 .mp3 或 .wav）或使用“fmod”或“cwave”库甚至其他库的任何其他声音格式的每个帧的频率？如何在 C/C++ 中找出这个频率？
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FFTW 库是一组非常快速的不同傅立叶变换的实现。
于 2012-06-01T13:00:22.170 回答
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If you have a number of samples of digitized audio, you pretty much have, in total, as many frequencies and phases as you've got samples. Suppose you've got just two samples of audio. In order to faithfully represent them, you need one frequency and one phase -- so again, two values. There is no "single" frequency to represent multiple samples of digitized audio.
You can of course, akin to the question of "How can I get the color of a specific video frame?", ask what is the average frequency. Or you can ask what is the most prominent frequency (the one with highest amplitude). Or you can ask what is the frequency that with its harmonics carries the most energy in the signal (assuming the signal was physical, like electrical current sampled in time).
In all those cases, you'd probably want to use a premade library that internally uses the FFT or a similar discrete transform to get the signal from the time domain to a frequency or a similar domain (quefrency domain, for example, and it's not a typo). It's hard to get what you want from a plain FFT, you'd need some mathematical training to process raw FFT results into what you're after. I'm sure there are libraries for it, I just can't think of any right now. Perhaps someone who deals with such work can edit the answer.
于 2012-06-01T20:36:44.077 回答