我想要做的是從某首歌曲中檢索頻率,並抑制所有未出現在人類聲音範圍或一般任何範圍內的頻率。這是我的抑制功能。從FFT抑制頻率
public void SupressAndWrite(Func<FrequencyUnit, bool> func)
{
this.WaveManipulated = true;
while (this.mainWave.WAVFile.NumSamplesRemaining > 0)
{
FrequencyUnit[] freqUnits = this.mainWave.NextFrequencyUnits();
Complex[] compUnits = (from item
in freqUnits
select (func(item)
? new Complex(item.Frequency, 0) :Complex.Zero))
.ToArray();
FourierTransform.FFT(compUnits, FourierTransform.Direction.Backward);
short[] shorts = (from item
in compUnits
select (short)item.Real).ToArray();
foreach (short item in shorts)
{
this.ManipulatedFile.AddSample16bit(item);
}
}
this.ManipulatedFile.Close();
}
這是我的課。
public sealed class ComplexWave
{
public readonly WAVFile WAVFile;
public readonly Int32 SampleSize;
private FourierTransform.Direction fourierDirection { get; set; }
private long position;
/// <param name="file"></param>
/// <param name="sampleSize in BLOCKS"></param>
public ComplexWave(WAVFile file, int sampleSize)
{
file.NullReferenceExceptionCheck();
this.WAVFile = file;
this.SampleSize = sampleSize;
if (this.SampleSize % 8 != 0)
{
if (this.SampleSize % 16 != 0)
{
throw new ArgumentException("Sample Size");
}
}
if (!MathTools.IsPowerOf2(sampleSize))
{
throw new ArgumentException("Sample Size");
}
this.fourierDirection = FourierTransform.Direction.Forward;
}
public Complex[] NextSampleFourierTransform()
{
short[] newInput = this.GetNextSample();
Complex[] data = newInput.CopyToComplex();
if (newInput.Any((x) => x != 0))
{
Debug.Write("done");
}
FourierTransform.FFT(data, this.fourierDirection);
return data;
}
public FrequencyUnit[] NextFrequencyUnits()
{
Complex[] cm = this.NextSampleFourierTransform();
FrequencyUnit[] freqUn = new FrequencyUnit[(cm.Length/2)];
int max = (cm.Length/2);
for (int i = 0; i < max; i++)
{
freqUn[i] = new FrequencyUnit(cm[i], this.WAVFile.SampleRateHz, i, cm.Length);
}
Array.Sort(freqUn);
return freqUn;
}
private short[] GetNextSample()
{
short[] retval = new short[this.SampleSize];
for (int i = 0; i < this.SampleSize; i++)
{
if (this.WAVFile.NumSamplesRemaining > 0)
{
retval[i] = this.WAVFile.GetNextSampleAs16Bit();
this.position++;
}
}
return retval;
}
}
FFT正向和FFT反向正常工作。你能告訴我我的錯誤是什麼。
丹妮拉的答案是正確的。但是,如果您的目標是消除某些頻率而不是其他頻率,則不應使用FFT。您應該使用時域方法:http://blog.bjornroche.com/2012/08/why-eq-is-完成時間domain.html –
@BjornRoche很高興我找到了你的博客,最後有人可以從中學習:) –