private void ProcessMono(float *baseBand, float *interleavedStereo, int length)
{
#region Prepare buffer
if (_channelABuffer == null || _channelABuffer.Length != length)
{
_channelABuffer = UnsafeBuffer.Create(length, sizeof(float));
_channelAPtr = (float *)_channelABuffer;
}
#endregion
#region Decimate L+R
Utils.Memcpy(_channelAPtr, baseBand, length * sizeof(float));
_channelADecimator.Process(_channelAPtr, length);
#endregion
#region Filter L+R
length /= _audioDecimationFactor;
_channelAFilter.Process(_channelAPtr, length);
#endregion
#region Process deemphasis
for (var i = 0; i < length; i++)
{
_deemphasisAvgL += _deemphasisAlpha * (_channelAPtr[i] - _deemphasisAvgL);
_channelAPtr[i] = _deemphasisAvgL;
}
#endregion
#region Fill output buffer
for (var i = 0; i < length; i++)
{
var sample = _channelAPtr[i] * AudioGain;
interleavedStereo[i * 2] = sample;
interleavedStereo[i * 2 + 1] = sample;
}
#endregion
}
private void ProcessStereo(float *baseBand, float *interleavedStereo, int length)
{
#region Prepare L+R buffer
if (_channelABuffer == null || _channelABuffer.Length != length)
{
_channelABuffer = UnsafeBuffer.Create(length, sizeof(float));
_channelAPtr = (float *)_channelABuffer;
}
#endregion
#region Prepare L-R buffer
if (_channelBBuffer == null || _channelBBuffer.Length != length)
{
_channelBBuffer = UnsafeBuffer.Create(length, sizeof(float));
_channelBPtr = (float *)_channelBBuffer;
}
#endregion
#region Decimate and filter L+R
var audioLength = length / _audioDecimationFactor;
if (_isMultiThreaded)
{
DSPThreadPool.QueueUserWorkItem(
delegate
{
Utils.Memcpy(_channelAPtr, baseBand, length * sizeof(float));
_channelADecimator.Process(_channelAPtr, length);
_channelAFilter.Process(_channelAPtr, audioLength);
_event.Set();
});
}
else
{
Utils.Memcpy(_channelAPtr, baseBand, length * sizeof(float));
_channelADecimator.Process(_channelAPtr, length);
_channelAFilter.Process(_channelAPtr, audioLength);
}
#endregion
#region Demodulate L-R
for (var i = 0; i < length; i++)
{
var pilot = _pilotFilter->Process(baseBand[i]);
_pll->Process(pilot);
_channelBPtr[i] = baseBand[i] * Trig.Sin((float)(_pll->AdjustedPhase * 2.0));
}
if (!_pll->IsLocked)
{
if (_isMultiThreaded)
{
_event.WaitOne();
}
#region Process mono deemphasis
for (var i = 0; i < audioLength; i++)
{
_deemphasisAvgL += _deemphasisAlpha * (_channelAPtr[i] - _deemphasisAvgL);
_channelAPtr[i] = _deemphasisAvgL;
}
#endregion
#region Fill output buffer with mono
for (var i = 0; i < audioLength; i++)
{
var sample = _channelAPtr[i] * AudioGain;
interleavedStereo[i * 2] = sample;
interleavedStereo[i * 2 + 1] = sample;
}
#endregion
return;
}
#endregion
#region Decimate and filter L-R
_channelBDecimator.Process(_channelBPtr, length);
_channelBFilter.Process(_channelBPtr, audioLength);
#endregion
#region Recover L and R audio channels
if (_isMultiThreaded)
{
_event.WaitOne();
}
for (var i = 0; i < audioLength; i++)
{
var a = _channelAPtr[i];
var b = 2f * _channelBPtr[i];
interleavedStereo[i * 2] = (a + b) * AudioGain;
interleavedStereo[i * 2 + 1] = (a - b) * AudioGain;
}
#endregion
#region Process deemphasis
for (var i = 0; i < audioLength; i++)
{
_deemphasisAvgL += _deemphasisAlpha * (interleavedStereo[i * 2] - _deemphasisAvgL);
interleavedStereo[i * 2] = _deemphasisAvgL;
_deemphasisAvgR += _deemphasisAlpha * (interleavedStereo[i * 2 + 1] - _deemphasisAvgR);
interleavedStereo[i * 2 + 1] = _deemphasisAvgR;
}
#endregion
}
