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/*
* ParamEq.cpp
* -----------
* Purpose: Implementation of the DMO Parametric Equalizer DSP (for non-Windows platforms)
* Notes : (currently none)
* Authors: OpenMPT Devs
* The OpenMPT source code is released under the BSD license. Read LICENSE for more details.
*/
#include "stdafx.h"
#ifndef NO_PLUGINS
#include "../../Sndfile.h"
#include "ParamEq.h"
#include "mpt/base/numbers.hpp"
#endif // !NO_PLUGINS
OPENMPT_NAMESPACE_BEGIN
#ifndef NO_PLUGINS
namespace DMO
{
IMixPlugin* ParamEq::Create(VSTPluginLib &factory, CSoundFile &sndFile, SNDMIXPLUGIN *mixStruct)
{
return new (std::nothrow) ParamEq(factory, sndFile, mixStruct);
}
ParamEq::ParamEq(VSTPluginLib &factory, CSoundFile &sndFile, SNDMIXPLUGIN *mixStruct)
: IMixPlugin(factory, sndFile, mixStruct)
, m_maxFreqParam(1.0f)
{
m_param[kEqCenter] = (8000.0f - 80.0f) / 15920.0f;
m_param[kEqBandwidth] = 0.314286f;
m_param[kEqGain] = 0.5f;
m_mixBuffer.Initialize(2, 2);
InsertIntoFactoryList();
}
void ParamEq::Process(float *pOutL, float *pOutR, uint32 numFrames)
{
if(!m_mixBuffer.Ok())
return;
const float *in[2] = { m_mixBuffer.GetInputBuffer(0), m_mixBuffer.GetInputBuffer(1) };
float *out[2] = { m_mixBuffer.GetOutputBuffer(0), m_mixBuffer.GetOutputBuffer(1) };
if(m_param[kEqGain] == 0.5f)
{
memcpy(out[0], in[0], numFrames * sizeof(float));
memcpy(out[1], in[1], numFrames * sizeof(float));
} else
{
for(uint32 i = numFrames; i != 0; i--)
{
for(uint8 channel = 0; channel < 2; channel++)
{
float x = *(in[channel])++;
float y = b0DIVa0 * x + b1DIVa0 * x1[channel] + b2DIVa0 * x2[channel] - a1DIVa0 * y1[channel] - a2DIVa0 * y2[channel];
x2[channel] = x1[channel];
x1[channel] = x;
y2[channel] = y1[channel];
y1[channel] = y;
*(out[channel])++ = y;
}
}
}
ProcessMixOps(pOutL, pOutR, m_mixBuffer.GetOutputBuffer(0), m_mixBuffer.GetOutputBuffer(1), numFrames);
}
PlugParamValue ParamEq::GetParameter(PlugParamIndex index)
{
if(index < kEqNumParameters)
{
return m_param[index];
}
return 0;
}
void ParamEq::SetParameter(PlugParamIndex index, PlugParamValue value)
{
if(index < kEqNumParameters)
{
value = mpt::safe_clamp(value, 0.0f, 1.0f);
m_param[index] = value;
RecalculateEqParams();
}
}
void ParamEq::Resume()
{
m_isResumed = true;
// Limit center frequency to a third of the sampling rate.
m_maxFreqParam = Clamp((m_SndFile.GetSampleRate() / 3.0f - 80.0f) / 15920.0f, 0.0f, 1.0f);
RecalculateEqParams();
PositionChanged();
}
void ParamEq::PositionChanged()
{
// Reset filter state
x1[0] = x2[0] = 0;
x1[1] = x2[1] = 0;
y1[0] = y2[0] = 0;
y1[1] = y2[1] = 0;
}
#ifdef MODPLUG_TRACKER
CString ParamEq::GetParamName(PlugParamIndex param)
{
switch(param)
{
case kEqCenter: return _T("Center");
case kEqBandwidth: return _T("Bandwidth");
case kEqGain: return _T("Gain");
}
return CString();
}
CString ParamEq::GetParamLabel(PlugParamIndex param)
{
switch(param)
{
case kEqCenter: return _T("Hz");
case kEqBandwidth: return _T("Semitones");
case kEqGain: return _T("dB");
}
return CString();
}
CString ParamEq::GetParamDisplay(PlugParamIndex param)
{
float value = 0.0f;
switch(param)
{
case kEqCenter:
value = FreqInHertz();
break;
case kEqBandwidth:
value = BandwidthInSemitones();
break;
case kEqGain:
value = GainInDecibel();
break;
}
CString s;
s.Format(_T("%.2f"), value);
return s;
}
#endif // MODPLUG_TRACKER
void ParamEq::RecalculateEqParams()
{
LimitMax(m_param[kEqCenter], m_maxFreqParam);
const float freq = FreqInHertz() / m_SndFile.GetSampleRate();
const float a = std::pow(10.0f, GainInDecibel() / 40.0f);
const float w0 = 2.0f * mpt::numbers::pi_v<float> * freq;
const float sinW0 = std::sin(w0);
const float cosW0 = std::cos(w0);
const float alpha = sinW0 * std::sinh((BandwidthInSemitones() * (mpt::numbers::ln2_v<float> / 24.0f)) * w0 / sinW0);
const float b0 = 1.0f + alpha * a;
const float b1 = -2.0f * cosW0;
const float b2 = 1.0f - alpha * a;
const float a0 = 1.0f + alpha / a;
const float a1 = -2.0f * cosW0;
const float a2 = 1.0f - alpha / a;
b0DIVa0 = b0 / a0;
b1DIVa0 = b1 / a0;
b2DIVa0 = b2 / a0;
a1DIVa0 = a1 / a0;
a2DIVa0 = a2 / a0;
}
} // namespace DMO
#else
MPT_MSVC_WORKAROUND_LNK4221(ParamEq)
#endif // !NO_PLUGINS
OPENMPT_NAMESPACE_END
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