获取a.wav文件C#的频谱线

Question

我想显示一个.wav 文件的频谱。 我不知道怎么做才对。 我使用 C# 和naudio nuget来处理音频数据。 当我插入所有 spec_data 点时，我只有一个填充数据的列。 （图一）现在的样子（图一）最后的样子

如何获取音频文件的所有频谱点？

 var buffer = new byte[fft_size];

 int bytes_read = fileStream.Read(buffer, 0, buffer.Length);
 int BYTES_PER_POINT = fileStream.WaveFormat.BitsPerSample / 8; //8Bit = 1Byte

 short[] values = new short[buffer.Length / BYTES_PER_POINT];

  for (int n = 0; n < BYTES_PER_POINT; n++)
  {

     for (int i = 0; i < bytes_read; i += BYTES_PER_POINT)
     {
        values[i / BYTES_PER_POINT] = (short)((buffer[i + 1] << 8) | buffer[i + 0]);
     }

  }
  neanalizir_values.AddRange(values);

---

 short[] data = new short[fft_size]; 
            data = neanalizir_values.GetRange(0, fft_size).ToArray(); 
            spec_data.RemoveAt(0); 
            List<double> new_data = new List<double>();
            Complex[] fft_buffer = new Complex[fft_size];
            for (int i = 0; i < fft_size; i++)
            {
                fft_buffer[i].X = (float)(neanalizir_values[i] * FastFourierTransform.HammingWindow(i, fft_size));
                fft_buffer[i].Y = 0;
            }
            FastFourierTransform.FFT(true, (int)Math.Log(fft_size, 2.0), fft_buffer);
            for (int i = 0; i < spec_data[spec_data.Count - 1].Count; i++)
            {
                double val;
                val = (double)fft_buffer[i].X + (double)fft_buffer[i].Y;
                val = Math.Abs(val);
                new_data.Add(val); 
            }
            new_data.Reverse(); 
            spec_data.Insert(spec_data.Count, new_data);  
            neanalizir_values.RemoveRange(0, fft_size / pixelsPerBuffer);

---

        Bitmap bitmap = new Bitmap(spec_data.Count, spec_data[0].Count, PixelFormat.Format8bppIndexed);
        ColorPalette pal = bitmap.Palette; 
        for (int i = 0; i < 256; i++)
            pal.Entries[i] = Color.FromArgb(255, i, i, i);
       bitmap.Palette = pal; 
        BitmapData bitmapData = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadOnly, bitmap.PixelFormat); 
        byte[] pixels = new byte[bitmapData.Stride * bitmap.Height]; 
        for (int col = 0; col < spec_data.Count; col++)
        {
            double scaleFactor = 40; 
            for (int row = 0; row < spec_data[col].Count; row++)
            {
                int bytePosition = row * bitmapData.Stride + col;
                double pixelVal = spec_data[col][row] * scaleFactor; 
                pixelVal = Math.Max(0, pixelVal); 
                pixelVal = Math.Min(255, pixelVal);
                pixels[bytePosition] = (byte)(pixelVal); 
            }
        }

        Marshal.Copy(pixels, 0, bitmapData.Scan0, pixels.Length); 
        bitmap.UnlockBits(bitmapData);
        pictureBox1.Image = bitmap;