LowPass2FilterNode::LowPass2FilterNode(AudioContext* context, float sampleRate)
: AudioBasicProcessorNode(context, sampleRate)
{
m_processor = adoptPtr(new BiquadProcessor(BiquadProcessor::LowPass, sampleRate, 1, false));
biquadProcessor()->parameter1()->setContext(context);
biquadProcessor()->parameter2()->setContext(context);
biquadProcessor()->parameter3()->setContext(context);
setNodeType(NodeTypeLowPass2Filter);
}
BiquadFilterNode::BiquadFilterNode(AudioContext* context, double sampleRate)
: AudioBasicProcessorNode(context, sampleRate)
{
// Initially setup as lowpass filter.
m_processor = adoptPtr(new BiquadProcessor(BiquadProcessor::LowPass, sampleRate, 1, false));
biquadProcessor()->parameter1()->setContext(context);
biquadProcessor()->parameter2()->setContext(context);
biquadProcessor()->parameter3()->setContext(context);
setType(NodeTypeBiquadFilter);
}
void BiquadDSPKernel::updateCoefficientsIfNecessary(bool useSmoothing, bool forceUpdate)
{
if (forceUpdate || biquadProcessor()->filterCoefficientsDirty()) {
double value1;
double value2;
double gain;
if (useSmoothing) {
value1 = biquadProcessor()->parameter1()->smoothedValue();
value2 = biquadProcessor()->parameter2()->smoothedValue();
gain = biquadProcessor()->parameter3()->smoothedValue();
} else {
value1 = biquadProcessor()->parameter1()->value();
value2 = biquadProcessor()->parameter2()->value();
gain = biquadProcessor()->parameter3()->value();
}
// Convert from Hertz to normalized frequency 0 -> 1.
double nyquist = this->nyquist();
double normalizedFrequency = value1 / nyquist;
// Configure the biquad with the new filter parameters for the appropriate type of filter.
switch (biquadProcessor()->type()) {
case BiquadProcessor::LowPass:
m_biquad.setLowpassParams(normalizedFrequency, value2);
break;
case BiquadProcessor::HighPass:
m_biquad.setHighpassParams(normalizedFrequency, value2);
break;
case BiquadProcessor::BandPass:
m_biquad.setBandpassParams(normalizedFrequency, value2);
break;
case BiquadProcessor::LowShelf:
m_biquad.setLowShelfParams(normalizedFrequency, gain);
break;
case BiquadProcessor::HighShelf:
m_biquad.setHighShelfParams(normalizedFrequency, gain);
break;
case BiquadProcessor::Peaking:
m_biquad.setPeakingParams(normalizedFrequency, value2, gain);
break;
case BiquadProcessor::Notch:
m_biquad.setNotchParams(normalizedFrequency, value2);
break;
case BiquadProcessor::Allpass:
m_biquad.setAllpassParams(normalizedFrequency, value2);
break;
}
}
}
bool BiquadFilterNode::setType(unsigned type)
{
if (type > BiquadProcessor::Allpass)
return false;
biquadProcessor()->setType(static_cast<BiquadProcessor::FilterType>(type));
return true;
}
void BiquadDSPKernel::getFrequencyResponse(int nFrequencies, const float* frequencyHz, float* magResponse, float* phaseResponse)
{
bool isGood = nFrequencies > 0 && frequencyHz && magResponse && phaseResponse;
ASSERT(isGood);
if (!isGood)
return;
Vector<float> frequency(nFrequencies);
double nyquist = this->nyquist();
// Convert from frequency in Hz to normalized frequency (0 -> 1),
// with 1 equal to the Nyquist frequency.
for (int k = 0; k < nFrequencies; ++k)
frequency[k] = narrowPrecisionToFloat(frequencyHz[k] / nyquist);
double cutoffFrequency;
double Q;
double gain;
double detune; // in Cents
{
// Get a copy of the current biquad filter coefficients so we can update the biquad with
// these values. We need to synchronize with process() to prevent process() from updating
// the filter coefficients while we're trying to access them. The process will update it
// next time around.
//
// The BiquadDSPKernel object here (along with it's Biquad object) is for querying the
// frequency response and is NOT the same as the one in process() which is used for
// performing the actual filtering. This one is is created in
// BiquadProcessor::getFrequencyResponse for this purpose. Both, however, point to the same
// BiquadProcessor object.
//
// FIXME: Simplify this: crbug.com/390266
MutexLocker processLocker(m_processLock);
cutoffFrequency = biquadProcessor()->parameter1().value();
Q = biquadProcessor()->parameter2().value();
gain = biquadProcessor()->parameter3().value();
detune = biquadProcessor()->parameter4().value();
}
updateCoefficients(cutoffFrequency, Q, gain, detune);
m_biquad.getFrequencyResponse(nFrequencies, frequency.data(), magResponse, phaseResponse);
}
void BiquadFilterNode::setType(unsigned short type, ExceptionCode& ec)
{
if (type > BiquadProcessor::Allpass) {
ec = NOT_SUPPORTED_ERR;
return;
}
biquadProcessor()->setType(static_cast<BiquadProcessor::FilterType>(type));
}
void BiquadFilterNode::getFrequencyResponse(const RefPtr<Float32Array>& frequencyHz, const RefPtr<Float32Array>& magResponse, const RefPtr<Float32Array>& phaseResponse)
{
if (!frequencyHz || !magResponse || !phaseResponse)
return;
int n = std::min(frequencyHz->length(), std::min(magResponse->length(), phaseResponse->length()));
if (n)
biquadProcessor()->getFrequencyResponse(n, frequencyHz->data(), magResponse->data(), phaseResponse->data());
}
void BiquadDSPKernel::process(const float* source, float* destination, size_t framesToProcess)
{
ASSERT(source && destination && biquadProcessor());
// Recompute filter coefficients if any of the parameters have changed.
// FIXME: as an optimization, implement a way that a Biquad object can simply copy its internal filter coefficients from another Biquad object.
// Then re-factor this code to only run for the first BiquadDSPKernel of each BiquadProcessor.
updateCoefficientsIfNecessary(true, false);
m_biquad.process(source, destination, framesToProcess);
}
void BiquadDSPKernel::process(const float* source, float* destination, size_t framesToProcess)
{
ASSERT(source && destination && biquadProcessor());
// Recompute filter coefficients if any of the parameters have changed.
// FIXME: as an optimization, implement a way that a Biquad object can simply copy its internal filter coefficients from another Biquad object.
// Then re-factor this code to only run for the first BiquadDSPKernel of each BiquadProcessor.
if (biquadProcessor()->filterCoefficientsDirty()) {
double value1 = biquadProcessor()->parameter1()->smoothedValue();
double value2 = biquadProcessor()->parameter2()->smoothedValue();
// Convert from Hertz to normalized frequency 0 -> 1.
double nyquist = this->nyquist();
double normalizedValue1 = value1 / nyquist;
// Configure the biquad with the new filter parameters for the appropriate type of filter.
switch (biquadProcessor()->type()) {
case BiquadProcessor::LowPass2:
m_biquad.setLowpassParams(normalizedValue1, value2);
break;
case BiquadProcessor::HighPass2:
m_biquad.setHighpassParams(normalizedValue1, value2);
break;
case BiquadProcessor::LowShelf:
m_biquad.setLowShelfParams(normalizedValue1, value2);
break;
// FIXME: add other biquad filter types...
case BiquadProcessor::Peaking:
case BiquadProcessor::Allpass:
case BiquadProcessor::HighShelf:
break;
}
}
m_biquad.process(source, destination, framesToProcess);
}
void BiquadDSPKernel::updateCoefficientsIfNecessary()
{
if (biquadProcessor()->filterCoefficientsDirty()) {
double cutoffFrequency;
double Q;
double gain;
double detune; // in Cents
if (biquadProcessor()->hasSampleAccurateValues()) {
cutoffFrequency = biquadProcessor()->parameter1().finalValue();
Q = biquadProcessor()->parameter2().finalValue();
gain = biquadProcessor()->parameter3().finalValue();
detune = biquadProcessor()->parameter4().finalValue();
} else {
cutoffFrequency = biquadProcessor()->parameter1().smoothedValue();
Q = biquadProcessor()->parameter2().smoothedValue();
gain = biquadProcessor()->parameter3().smoothedValue();
detune = biquadProcessor()->parameter4().smoothedValue();
}
updateCoefficients(cutoffFrequency, Q, gain, detune);
}
}
void BiquadDSPKernel::updateCoefficients(double cutoffFrequency, double Q, double gain, double detune)
{
// Convert from Hertz to normalized frequency 0 -> 1.
double nyquist = this->nyquist();
double normalizedFrequency = cutoffFrequency / nyquist;
// Offset frequency by detune.
if (detune)
normalizedFrequency *= pow(2, detune / 1200);
// Configure the biquad with the new filter parameters for the appropriate type of filter.
switch (biquadProcessor()->type()) {
case BiquadProcessor::LowPass:
m_biquad.setLowpassParams(normalizedFrequency, Q);
break;
case BiquadProcessor::HighPass:
m_biquad.setHighpassParams(normalizedFrequency, Q);
break;
case BiquadProcessor::BandPass:
m_biquad.setBandpassParams(normalizedFrequency, Q);
break;
case BiquadProcessor::LowShelf:
m_biquad.setLowShelfParams(normalizedFrequency, gain);
break;
case BiquadProcessor::HighShelf:
m_biquad.setHighShelfParams(normalizedFrequency, gain);
break;
case BiquadProcessor::Peaking:
m_biquad.setPeakingParams(normalizedFrequency, Q, gain);
break;
case BiquadProcessor::Notch:
m_biquad.setNotchParams(normalizedFrequency, Q);
break;
case BiquadProcessor::Allpass:
m_biquad.setAllpassParams(normalizedFrequency, Q);
break;
}
}
void BiquadDSPKernel::process(const float* source, float* destination, size_t framesToProcess)
{
ASSERT(source);
ASSERT(destination);
ASSERT(biquadProcessor());
// Recompute filter coefficients if any of the parameters have changed.
// FIXME: as an optimization, implement a way that a Biquad object can simply copy its internal filter coefficients from another Biquad object.
// Then re-factor this code to only run for the first BiquadDSPKernel of each BiquadProcessor.
// The audio thread can't block on this lock; skip updating the coefficients for this block if
// necessary. We'll get them the next time around.
{
MutexTryLocker tryLocker(m_processLock);
if (tryLocker.locked())
updateCoefficientsIfNecessary();
}
m_biquad.process(source, destination, framesToProcess);
}
void BiquadFilterNode::setType(BiquadFilterType type)
{
biquadProcessor()->setType(type);
}
