private void ComputeDo3Band(byte[] pkgData, long lBytesToWrite, WAVEFORMATEXTENSION _waveFormat)
{
if (GetAudioData(pkgData, lBytesToWrite, _waveFormat))
{
EQSTATE eqs = new EQSTATE();
AudioBandsConfig.init_3band_state(eqs, LowFrequence, HighFrequence, (int)_waveFormat.NSamplesPerSec);
//for (int i = 0; i < m_nNumSamples; i++)
for (int i = 0; i < m_RealIn_RT.Count; i++)
{
m_Band_arr.Add(AudioBandsConfig.do_3band(eqs, m_RealIn_RT[i]));
m_BandLow_arr.Add(AudioBandsConfig.do_3bandLow(eqs, m_RealIn_LT[i]));
}
double A2, dSum = 0, A2Low, dSumLow = 0;
for (int i = 0; i < m_Band_arr.Count; i++)
{
A2 = m_Band_arr[i] * m_Band_arr[i];
dSum += A2;
A2Low = m_BandLow_arr[i] * m_BandLow_arr[i];
dSumLow += A2Low;
}
double dAvg = dSum / m_nNumSamples;
double dAvgLow = dSumLow / m_nNumSamples;
double dFinal = Math.Sqrt(dAvg);
double dFinalLow = Math.Sqrt(dAvgLow);
double dOutput = dFinal * Math.Sqrt(2) / 32768 * 100;
double dOutputLow = dFinalLow * Math.Sqrt(2) / 32768 * 100;
_audiopluseCallBack(dOutput, dOutputLow);
}
}
/// <summary>
/// Initialize EQ
///
/// Recommended frequencies are ...
/// lowfreq = 880 Hz
/// highfreq = 5000 Hz
/// Set mixfreq to whatever rate your system is using (eg 48Khz)
/// </summary>
public static void init_3band_state(EQSTATE es, int lowfreq, int highfreq, int mixfreq)
{
// Clear state
// Set Low/Mid/High gains to unity
es.lg = 5.0; // updated to fine tune
es.mg = 1.0;
es.hg = 8.0; // updated to fine tune output
// Calculate filter cutoff frequencies
es.lf = 2 * Math.Sin(Math.PI * ((double)lowfreq / (double)mixfreq));
es.hf = 2 * Math.Sin(Math.PI * ((double)highfreq / (double)mixfreq));
}
const double vsa = (1.0 / 4294967295.0); // Very small amount (Denormal Fix)
/// <summary>
/// Gets the high value based on a sample and a EQSTATE.
///
/// sample can be any range you like :)
/// Note that the output will depend on the gain settings for each band
/// (especially the bass) so may require clipping before output, but you
/// knew that anyway :)
/// </summary>
public static double do_3band(EQSTATE es, double sample)
{
// Locals
double l, m, h; // Low / Mid / High - Sample Values
// Filter #1 (lowpass)
es.f1p0 += (es.lf * (sample - es.f1p0)) + vsa;
es.f1p1 += (es.lf * (es.f1p0 - es.f1p1));
es.f1p2 += (es.lf * (es.f1p1 - es.f1p2));
es.f1p3 += (es.lf * (es.f1p2 - es.f1p3));
l = es.f1p3;
// Filter #2 (highpass)
es.f2p0 += (es.hf * (sample - es.f2p0)) + vsa;
es.f2p1 += (es.hf * (es.f2p0 - es.f2p1));
es.f2p2 += (es.hf * (es.f2p1 - es.f2p2));
es.f2p3 += (es.hf * (es.f2p2 - es.f2p3));
h = es.sdm3 - es.f2p3;
// Calculate midrange (signal - (low + high))
m = es.sdm3 - (h + l);
// Scale, Combine and store
l *= es.lg;
m *= es.mg;
h *= es.hg;
// Shuffle history buffer
es.sdm3 = es.sdm2;
es.sdm2 = es.sdm1;
es.sdm1 = sample;
return(h);
}
float do_3band(ref EQSTATE es, float sample)
{
float l, m, h;
es.f1p0 += (es.lf * (sample - es.f1p0)) + vsa;
es.f1p1 += (es.lf * (es.f1p0 - es.f1p1));
es.f1p2 += (es.lf * (es.f1p1 - es.f1p2));
es.f1p3 += (es.lf * (es.f1p2 - es.f1p3));
l = es.f1p3;
es.f2p0 += (es.hf * (sample - es.f2p0)) + vsa;
es.f2p1 += (es.hf * (es.f2p0 - es.f2p1));
es.f2p2 += (es.hf * (es.f2p1 - es.f2p2));
es.f2p3 += (es.hf * (es.f2p2 - es.f2p3));
h = es.sdm3 - es.f2p3;
m = es.sdm3 - (h + l);
l *= es.lg;
m *= es.mg;
h *= es.hg;
es.sdm3 = es.sdm2;
es.sdm2 = es.sdm1;
es.sdm1 = sample;
return(l + m + h);
}
void init_3band_state(ref EQSTATE es, int lowfreq, int highfreq, int mixfreq)
{
es.lg = 1.0f; es.mg = 1.0f; es.hg = 1.0f;
es.lf = 2f * Mathf.Sin(Mathf.PI * ((float)lowfreq / (float)mixfreq));
es.hf = 2f * Mathf.Sin(Mathf.PI * ((float)highfreq / (float)mixfreq));
}