快速傅立葉變換的C＃

Question

可能重複：
Fast fourier transform in c#

我要尋找或麥克風的音頻數據線進行實時FFT（快速傅立葉變換）的例子在C＃中。我的目標是實時確定音頻數據中是否存在特定音符。任何例子讚賞。

Answer 1

AForge.NET是一個具有快速傅里葉變換支持的開源庫。
ExocortexDSP也是另一種選擇。

ExocortexDSP例子是這個樣子：

Exocortex.DSP.ComplexF[] complexData = new Exocortex.DSP.ComplexF[512]; 
    for (int i = 0; i < 512; ++i) 
    { 
     // Fill the complex data 
     complexData[i].Re = 1; // Add your real part here 
     complexData[i].Im = 2; // Add your imaginary part here 
    } 

    // FFT the time domain data to get frequency domain data 
    Exocortex.DSP.Fourier.FFT(complexData, Exocortex.DSP.FourierDirection.Forward); 

    float[] mag_dat_buffer = new float[complexData.Length]; 
    // Loop through FFT'ed data and do something with it 
    for (int i = 0; i < complexData.Length; ++i) 
    { 
     // Calculate magnitude or do something with the new complex data 
     mag_data_buffer[i] = ImaginaryNumberMagnitude(complexData[i].Im, complexData[i].Re); 
    }