private void CreateFilters()
{
lock (_lockObj)
{
_filters.Clear();
foreach (var band in _bands)
{
var filter = new BiQuadFilter[_channels];
for (var n = 0; n < _channels; n++)
{
filter[n] = BiQuadFilter.PeakingEQ(_sourceProvider.WaveFormat.SampleRate, band.Frequency,
band.Bandwidth, band.Gain);
}
_filters.Add(filter);
}
}
}
/// <summary>
/// Create a High pass filter
/// </summary>
public static BiQuadFilter HighPassFilter(float sampleRate, float cutoffFrequency, float q)
{
var filter = new BiQuadFilter();
filter.SetHighPassFilter(sampleRate, cutoffFrequency, q);
return filter;
}
/// <summary>
/// Create a Peaking EQ
/// </summary>
public static BiQuadFilter PeakingEQ(float sampleRate, float centreFrequency, float q, float dbGain)
{
var filter = new BiQuadFilter();
filter.SetPeakingEq(sampleRate, centreFrequency, q, dbGain);
return(filter);
}
/// <summary>
/// Create a low pass filter
/// </summary>
// Token: 0x06000344 RID: 836 RVA: 0x0000B03C File Offset: 0x0000923C
public static BiQuadFilter LowPassFilter(float sampleRate, float cutoffFrequency, float q)
{
BiQuadFilter biQuadFilter = new BiQuadFilter();
biQuadFilter.SetLowPassFilter(sampleRate, cutoffFrequency, q);
return(biQuadFilter);
}
// Trigger this with keystroke, VR input, UI button, etc.
// Don't do this every time the person starts/stops sending data, instead,
// use this method when the game starts up, or when you want to make the mic
// available. Audio won't actually go through unless the code in Update()
// can successfully give the networking system an AudioPacket. Interrupt
// it before it delivers the packet, and no data will be sent. VoipReceivers
// on the other side will intelligently interpret this as packet loss and
// wait for new data.
public void StartTransmitting()
{
if (isTransmitting)
{
return;
}
Debug.Log("Voip Test Transmit");
Debug.Log("Beginning VOIP transmit");
lastSamplePosition = 0;
lastSampleTime = 0;
int maxFreq = 0;
int minFreq = 0;
string deviceName = Microphone.devices[0];
Microphone.GetDeviceCaps(deviceName, out minFreq, out maxFreq);
//Record at lowest frequency possible.
//This makes the downsampling process a little less painful.
SOURCE_FREQUENCY = minFreq;
DEVICE = deviceName;
lastClip = Microphone.Start(deviceName, true, 60, SOURCE_FREQUENCY);
Debug.Log("Mic name: " + deviceName + ", freq: " + SOURCE_FREQUENCY);
downsampler = new NAudio.Wave.Compression.AcmStream(new NAudio.Wave.WaveFormat(SOURCE_FREQUENCY, 16, 1), new NAudio.Wave.WaveFormat(TRANSMIT_FREQUENCY, 16, 1));
bitreduce = new NAudio.Wave.Compression.AcmStream(new NAudio.Wave.WaveFormat(TRANSMIT_FREQUENCY, 16, 1), new NAudio.Wave.WaveFormat(TRANSMIT_FREQUENCY, 8, 1));
lowPassFilter = NAudio.Dsp.BiQuadFilter.LowPassFilter(SOURCE_FREQUENCY, TRANSMIT_FREQUENCY * 0.5f, lowPassQuality);
Debug.Log("Channels: " + lastClip.channels);
Debug.Log("Bitconvert is little endian? " + BitConverter.IsLittleEndian);
isTransmitting = true;
}
/// <summary>
/// Create a High pass filter
/// </summary>
public static BiQuadFilter HighPassFilter(float sampleRate, float cutoffFrequency, float q)
{
var filter = new BiQuadFilter();
filter.SetHighPassFilter(sampleRate, cutoffFrequency, q);
return(filter);
}
/// <summary>
/// H(s) = (s/Q) / (s^2 + s/Q + 1) (constant 0 dB peak gain)
/// </summary>
public static BiQuadFilter BandPassFilterConstantPeakGain(float sampleRate, float centreFrequency, float q)
{
double w0 = 2 * Math.PI * centreFrequency / sampleRate;
double cosw0 = Math.Cos(w0);
double sinw0 = Math.Sin(w0);
double alpha = sinw0 / (2 * q);
BiQuadFilter filter = new BiQuadFilter();
filter.b0 = alpha;
filter.b1 = 0;
filter.b2 = -alpha;
filter.a0 = 1 + alpha;
filter.a1 = -2 * cosw0;
filter.a2 = 1 - alpha;
return filter;
}
/// <summary>
/// H(s) = s^2 / (s^2 + s/Q + 1)
/// </summary>
public static BiQuadFilter HighPassFilter(float sampleRate, float cutoffFrequency, float q)
{
double w0 = 2 * Math.PI * cutoffFrequency / sampleRate;
double cosw0 = Math.Cos(w0);
double alpha = Math.Sin(w0) / (2 * q);
BiQuadFilter filter = new BiQuadFilter();
filter.b0 = (1 + Math.Cos(w0))/2;
filter.b1 = -(1 + Math.Cos(w0));
filter.b2 = (1 + Math.Cos(w0))/2;
filter.a0 = 1 + alpha;
filter.a1 = -2*Math.Cos(w0);
filter.a2 = 1 - alpha;
return filter;
}
/// <summary>
/// H(s) = s^2 / (s^2 + s/Q + 1)
/// </summary>
public static BiQuadFilter HighPassFilter(float sampleRate, float cutoffFrequency, float q)
{
double w0 = 2 * Math.PI * cutoffFrequency / sampleRate;
double cosw0 = Math.Cos(w0);
double alpha = Math.Sin(w0) / (2 * q);
var filter = new BiQuadFilter();
filter.b0 = (1 + Math.Cos(w0)) / 2;
filter.b1 = -(1 + Math.Cos(w0));
filter.b2 = (1 + Math.Cos(w0)) / 2;
filter.a0 = 1 + alpha;
filter.a1 = -2 * Math.Cos(w0);
filter.a2 = 1 - alpha;
return(filter);
}
/// <summary>
/// H(s) = (s/Q) / (s^2 + s/Q + 1) (constant 0 dB peak gain)
/// </summary>
public static BiQuadFilter BandPassFilterConstantPeakGain(float sampleRate, float centreFrequency, float q)
{
double w0 = 2 * Math.PI * centreFrequency / sampleRate;
double cosw0 = Math.Cos(w0);
double sinw0 = Math.Sin(w0);
double alpha = sinw0 / (2 * q);
var filter = new BiQuadFilter();
filter.b0 = alpha;
filter.b1 = 0;
filter.b2 = -alpha;
filter.a0 = 1 + alpha;
filter.a1 = -2 * cosw0;
filter.a2 = 1 - alpha;
return(filter);
}
/// <summary>
/// H(s) = (s^2 + 1) / (s^2 + s/Q + 1)
/// </summary>
public static BiQuadFilter NotchFilter(float sampleRate, float centreFrequency, float q)
{
double w0 = 2 * Math.PI * centreFrequency / sampleRate;
double cosw0 = Math.Cos(w0);
double sinw0 = Math.Sin(w0);
double alpha = sinw0 / (2 * q);
BiQuadFilter filter = new BiQuadFilter();
filter.b0 = 1;
filter.b1 = -2 * cosw0;
filter.b2 = 1;
filter.a0 = 1 + alpha;
filter.a1 = -2 * cosw0;
filter.a2 = 1 - alpha;
return(filter);
}
/// <summary>
/// H(s) = A * (s^2 + (sqrt(A)/Q)*s + A)/(A*s^2 + (sqrt(A)/Q)*s + 1)
/// </summary>
/// <param name="sampleRate"></param>
/// <param name="cutoffFrequency"></param>
/// <param name="shelfSlope">a "shelf slope" parameter (for shelving EQ only).
/// When S = 1, the shelf slope is as steep as it can be and remain monotonically
/// increasing or decreasing gain with frequency. The shelf slope, in dB/octave,
/// remains proportional to S for all other values for a fixed f0/Fs and dBgain.</param>
/// <param name="dbGain">Gain in decibels</param>
public static BiQuadFilter LowShelf(float sampleRate, float cutoffFrequency, float shelfSlope, float dbGain)
{
double w0 = 2 * Math.PI * cutoffFrequency / sampleRate;
double cosw0 = Math.Cos(w0);
double sinw0 = Math.Sin(w0);
double A = Math.Pow(10, dbGain / 40); // TODO: should we square root this value?
double alpha = sinw0 / 2 * Math.Sqrt((A + 1 / A) * (1 / shelfSlope - 1) + 2);
double temp = 2 * Math.Sqrt(A) * alpha;
var filter = new BiQuadFilter();
filter.b0 = A * ((A + 1) - (A - 1) * cosw0 + temp);
filter.b1 = 2 * A * ((A - 1) - (A + 1) * cosw0);
filter.b2 = A * ((A + 1) - (A - 1) * cosw0 - temp);
filter.a0 = (A + 1) + (A - 1) * cosw0 + temp;
filter.a1 = -2 * ((A - 1) + (A + 1) * cosw0);
filter.a2 = (A + 1) + (A - 1) * cosw0 - temp;
return(filter);
}
/// <summary>
/// H(s) = (s^2 + s*(A/Q) + 1) / (s^2 + s/(A*Q) + 1)
/// </summary>
public static BiQuadFilter PeakingEQ(float sampleRate, float centreFrequency, float q, float dbGain)
{
double w0 = 2 * Math.PI * centreFrequency / sampleRate;
double cosw0 = Math.Cos(w0);
double sinw0 = Math.Sin(w0);
double alpha = sinw0 / (2 * q);
double A = Math.Pow(10, dbGain / 40); // TODO: should we square root this value?
var filter = new BiQuadFilter();
filter.b0 = 1 + alpha * A;
filter.b1 = -2 * cosw0;
filter.b2 = 1 - alpha * A;
filter.a0 = 1 + alpha / A;
filter.a1 = -2 * cosw0;
filter.a2 = 1 - alpha / A;
return(filter);
}
/// <summary>
/// H(s) = (s^2 + 1) / (s^2 + s/Q + 1)
/// </summary>
public static BiQuadFilter NotchFilter(float sampleRate, float centreFrequency, float q)
{
double w0 = 2*Math.PI*centreFrequency/sampleRate;
double cosw0 = Math.Cos(w0);
double sinw0 = Math.Sin(w0);
double alpha = sinw0/(2*q);
var filter = new BiQuadFilter();
filter.b0 = 1;
filter.b1 = -2*cosw0;
filter.b2 = 1;
filter.a0 = 1 + alpha;
filter.a1 = -2*cosw0;
filter.a2 = 1 - alpha;
return filter;
}
/// <summary>
/// H(s) = A * (A*s^2 + (sqrt(A)/Q)*s + 1)/(s^2 + (sqrt(A)/Q)*s + A)
/// </summary>
/// <param name="sampleRate"></param>
/// <param name="cutoffFrequency"></param>
/// <param name="shelfSlope"></param>
/// <param name="dbGain"></param>
/// <returns></returns>
public static BiQuadFilter HighShelf(float sampleRate, float cutoffFrequency, float shelfSlope, float dbGain)
{
double w0 = 2 * Math.PI * cutoffFrequency / sampleRate;
double cosw0 = Math.Cos(w0);
double sinw0 = Math.Sin(w0);
double A = Math.Pow(10, dbGain / 40); // TODO: should we square root this value?
double alpha = sinw0 / 2 * Math.Sqrt((A + 1 / A) * (1 / shelfSlope - 1) + 2);
double temp = 2 * Math.Sqrt(A) * alpha;
BiQuadFilter filter = new BiQuadFilter();
filter.b0 = A*( (A+1) + (A-1)*cosw0 + temp );
filter.b1 = -2*A*( (A-1) + (A+1)*cosw0 );
filter.b2 = A*( (A+1) + (A-1)*cosw0 - temp );
filter.a0 = (A+1) - (A-1)*cosw0 + temp;
filter.a1 = 2*( (A-1) - (A+1)*cosw0 );
filter.a2 = (A+1) - (A-1)*cosw0 - temp;
return filter;
}
/// <summary>
/// H(s) = (s^2 + s*(A/Q) + 1) / (s^2 + s/(A*Q) + 1)
/// </summary>
public static BiQuadFilter PeakingEQ(float sampleRate, float centreFrequency, float q, float dbGain)
{
double w0 = 2 * Math.PI * centreFrequency / sampleRate;
double cosw0 = Math.Cos(w0);
double sinw0 = Math.Sin(w0);
double alpha = sinw0 / (2 * q);
double A = Math.Pow(10, dbGain / 40); // TODO: should we square root this value?
BiQuadFilter filter = new BiQuadFilter();
filter.b0 = 1 + alpha*A;
filter.b1 = -2*cosw0;
filter.b2 = 1 - alpha*A;
filter.a0 = 1 + alpha/A;
filter.a1 = -2*cosw0;
filter.a2 = 1 - alpha/A;
return filter;
}
/// <summary>
/// Creating a new MixingSampleProvider with a collection of sources
/// </summary>
/// <param name="sources"></param>
public MyMixingSampleProvider(IEnumerable<ISampleProvider> sources)
{
env.AttackRate = 44100f;
env.DecayRate = 44100f;
env.SustainLevel = .8f;
env.ReleaseRate = 44100f;
filter = BiQuadFilter.LowPassFilter(44100f, cutoffFrq, 1);
this.sources = new List<ISampleProvider>();
foreach (var source in sources)
{
AddMixerInput(source);
}
if (this.sources.Count == 0)
{
throw new ArgumentException("Must provide at least one input in this constructor");
}
}
/// <summary>
/// Create a Peaking EQ
/// </summary>
public static BiQuadFilter PeakingEQ(float sampleRate, float centreFrequency, float q, float dbGain)
{
var filter = new BiQuadFilter();
filter.SetPeakingEq(sampleRate, centreFrequency, q, dbGain);
return filter;
}
