目前我正在使用directsound API实时开发c＃低通滤波器。我遇到的问题是低通滤波器的各种实现似乎不适用于我的echo实现。在过滤开始时，我有一个从捕获缓冲区读取的字节数组（读取）。该数组的值介于0和255之间。
当我对数组进行低通滤波算法时，我获得的值介于0和1之间，并且播放数组是静音的（仅为零）。我附上相关代码。
我认为这种方法是错误的，输入数据可能看起来不同，因为低通算法似乎完全杀了它。有任何想法吗？提前谢谢。
在KillaKem的评论之后更新了相关代码：
//buffer format
var format = new WaveFormat
{
SamplesPerSecond = 44100,
BitsPerSample = 16,
Channels = 2,
FormatTag = WaveFormatTag.Pcm
};
//reading the buffer
byte[] read = (byte[])_dwCapBuffer.Read(offset, typeof(byte), LockFlag.None, _dwOutputBufferSize);
byte[] play = new byte [read.Length];
byte[] readL= new byte [read.Length/2];
byte[] readR= new byte [read.Length/2];
byte[] playL = new byte[read.Length / 2];
byte[] playR = new byte[read.Length / 2];
float[] readLfloat = new float[read.Length / 4];
float[] readRfloat = new float[read.Length / 4];
float[] playLfloat = new float[read.Length / 4];
float[] playRfloat = new float[read.Length / 4];
//dividing into channels and casting to float
for(int i = 0; i<read.Length; i=i+1)
{
if (i % 4 == 0)
{
readL[(int)i / 2] = read[i];
}
if(i%4==1)
{
readL[(int)i/2]=read[i];
readLfloat[(int)i / 4] = (((short)(read[i-1] << 8 | read[i])) / 32768f);
}
if (i % 4 == 2)
{
readR[(int)i / 2] = read[i];
}
if (i % 4 == 3)
{
readR[(int)i / 2] = read[i];
readRfloat[(int)i / 4] = (((short)(read[i - 1] << 8 | read[i])) / 32768f);
}
}
//filter coefficients
float frequency = 1000f;
float sampleRate = (float)_dwCapBuffer.Format.SamplesPerSecond;
float resonance = 0.5f;
float c = 1.0f / (float)Math.Tan(Math.PI * frequency / sampleRate);
float a0 = 1.0f / (1.0f + resonance * c + c * c);
float a1 = 2f * a0;
float a2 = a0;
float b1 = 2.0f * (1.0f - c * c) * a0;
float b2 = (1.0f - resonance * c + c * c) * a0;
//filtering
for(int i = 0; i < readLfloat.Length; i++)
{
float readCurrSample = readLfloat[i];
float playCurrSample = playLfloat[i];
float filtered=readCurrSample;
float readOneSample;
float readTwoSample;
float playOneSample;
float playTwoSample;
if (i ==0)
{
filtered = ((float)a0 * readCurrSample) + ((float)a1 * savelastRead) + ((float)a2 * saveprelastRead) - ((float)b1 * savelastPlay) - ((float)b2 * saveprelastPlay);
}
else if (i==1)
{
readOneSample = readLfloat[i-1];
playOneSample = playLfloat[i-1];
filtered = ((float)a0 * readCurrSample) + ((float)a1 * readOneSample) + ((float)a2 * savelastRead) - ((float)b1 * playOneSample) - ((float)b2 * savelastPlay);
}
else
{
readOneSample = readLfloat[i - 1];
playOneSample = playLfloat[i - 1];
readTwoSample = readLfloat[i - 2];
playTwoSample = playLfloat[i - 2];
filtered = ((float)a0 * readCurrSample) + ((float)a1 * readOneSample) + ((float)a2 * readTwoSample) - ((float)b1 * playOneSample) - ((float)b2 * playTwoSample);
}
if (i == readL.Length - 4)
{
saveprelastPlay = playCurrSample;
saveprelastRead = readCurrSample;
}
if (i == readL.Length-2)
{
savelastPlay = playCurrSample;
savelastRead = readCurrSample;
}
if (filtered > 1 || filtered < -1)
{
int x = 0;
}
playLfloat[i] = filtered;
}
playRfloat = playLfloat; //ignoring Right channel operations
//Recasting to bytes array
for (int i = 0; i < read.Length; i = i + 1)
{
if (i % 4 == 1)
{
byte[] bytes;
bytes = BitConverter.GetBytes((short)(playLfloat[(int)(i-1)/4] * 32768f));
read[i] = bytes[0];
read[i - 1] = bytes[1];
}
if (i % 4 == 3)
{
byte[] bytes;
bytes = BitConverter.GetBytes((short)(playRfloat[(int)(i - 1) / 4] * 32768f));
read[i] = bytes[0];
read[i - 1] = bytes[1];
}
}