Chris@0: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@0: 
Chris@0: #include "flattendynamics-ladspa.h"
Chris@0: 
Chris@0: #include <iostream>
Chris@0: #include <cmath>
Chris@0: 
Chris@2: using std::cerr;
Chris@2: using std::endl;
Chris@2: 
Chris@7: const float longTermSeconds = 4.f;
Chris@9: const float shortTermSeconds = 1.f;
Chris@9: const float catchUpSeconds = 0.2f;
Chris@13: const float targetMaxRMS = 0.04f;
Chris@14: const float rmsMaxDecay = 0.999f; // per sample
Chris@3: const float maxGain = 20.f;
Chris@1: 
Chris@0: const char *const
Chris@0: FlattenDynamics::portNames[PortCount] =
Chris@0: {
Chris@0:     "Input",
Chris@0:     "Output",
Chris@1:     "Gain",
Chris@0: };
Chris@0: 
Chris@0: const LADSPA_PortDescriptor 
Chris@0: FlattenDynamics::ports[PortCount] =
Chris@0: {
Chris@0:     LADSPA_PORT_INPUT  | LADSPA_PORT_AUDIO,
Chris@0:     LADSPA_PORT_OUTPUT | LADSPA_PORT_AUDIO,
Chris@1:     LADSPA_PORT_OUTPUT | LADSPA_PORT_CONTROL,
Chris@0: };
Chris@0: 
Chris@0: const LADSPA_PortRangeHint 
Chris@0: FlattenDynamics::hints[PortCount] =
Chris@0: {
Chris@0:     { 0, 0, 0 },
Chris@0:     { 0, 0, 0 },
Chris@1:     { 0, 0, 0 },
Chris@0: };
Chris@0: 
Chris@0: const LADSPA_Properties
Chris@0: FlattenDynamics::properties = LADSPA_PROPERTY_HARD_RT_CAPABLE;
Chris@0: 
Chris@0: const LADSPA_Descriptor 
Chris@0: FlattenDynamics::ladspaDescriptor =
Chris@0: {
Chris@0:     0xf0b375, // "Unique" ID
Chris@0:     "flattendynamics", // Label
Chris@0:     properties,
Chris@2:     "Flatten Dynamics", // Name
Chris@0:     "Queen Mary, University of London", // Maker
Chris@0:     "BSD", // Copyright
Chris@0:     PortCount,
Chris@0:     ports,
Chris@0:     portNames,
Chris@0:     hints,
Chris@0:     0, // Implementation data
Chris@0:     instantiate,
Chris@0:     connectPort,
Chris@0:     activate,
Chris@0:     run,
Chris@0:     0, // Run adding
Chris@0:     0, // Set run adding gain
Chris@0:     deactivate,
Chris@0:     cleanup
Chris@0: };
Chris@0: 
Chris@0: const LADSPA_Descriptor *
Chris@0: FlattenDynamics::getDescriptor(unsigned long index)
Chris@0: {
Chris@0:     if (index == 0) return &ladspaDescriptor;
Chris@0:     return 0;
Chris@0: }
Chris@0: 
Chris@0: FlattenDynamics::FlattenDynamics(int sampleRate) :
Chris@0:     m_sampleRate(sampleRate),
Chris@0:     m_input(0),
Chris@1:     m_output(0),
Chris@1:     m_pgain(0),
Chris@1:     m_history(0),
Chris@1:     m_histlen(0),
Chris@1:     m_histwrite(0),
Chris@1:     m_histread(0),
Chris@7:     m_sumOfSquaresLongTerm(0.f),
Chris@7:     m_sumOfSquaresShortTerm(0.f),
Chris@7:     m_rmsLongTerm(0.f),
Chris@7:     m_rmsShortTerm(0.f),
Chris@7:     m_maxRmsLongTerm(0.f),
Chris@8:     m_maxRmsShortTerm(0.f),
Chris@1:     m_gain(1.f)
Chris@0: {
Chris@0:     reset();
Chris@0: }
Chris@0: 
Chris@0: FlattenDynamics::~FlattenDynamics()
Chris@0: {
Chris@3:     delete[] m_history;
Chris@0: }
Chris@0:     
Chris@0: LADSPA_Handle
Chris@0: FlattenDynamics::instantiate(const LADSPA_Descriptor *, unsigned long rate)
Chris@0: {
Chris@0:     FlattenDynamics *flatten = new FlattenDynamics(rate);
Chris@0:     return flatten;
Chris@0: }
Chris@0: 
Chris@0: void
Chris@0: FlattenDynamics::connectPort(LADSPA_Handle handle,
Chris@2:                              unsigned long port, LADSPA_Data *location)
Chris@0: {
Chris@0:     FlattenDynamics *flatten = (FlattenDynamics *)handle;
Chris@0: 
Chris@0:     float **ports[PortCount] = {
Chris@0: 	&flatten->m_input,
Chris@0: 	&flatten->m_output,
Chris@1:         &flatten->m_pgain,
Chris@0:     };
Chris@0: 
Chris@0:     *ports[port] = (float *)location;
Chris@0: }
Chris@0: 
Chris@0: void
Chris@0: FlattenDynamics::activate(LADSPA_Handle handle)
Chris@0: {
Chris@0:     FlattenDynamics *flatten = (FlattenDynamics *)handle;
Chris@0:     flatten->reset();
Chris@0: }
Chris@0: 
Chris@0: void
Chris@0: FlattenDynamics::run(LADSPA_Handle handle, unsigned long samples)
Chris@0: {
Chris@0:     FlattenDynamics *flatten = (FlattenDynamics *)handle;
Chris@0:     flatten->runImpl(samples);
Chris@0: }
Chris@0: 
Chris@0: void
Chris@0: FlattenDynamics::deactivate(LADSPA_Handle handle)
Chris@0: {
Chris@0:     activate(handle); // both functions just reset the plugin
Chris@0: }
Chris@0: 
Chris@0: void
Chris@0: FlattenDynamics::cleanup(LADSPA_Handle handle)
Chris@0: {
Chris@0:     delete (FlattenDynamics *)handle;
Chris@0: }
Chris@0: 
Chris@0: void
Chris@0: FlattenDynamics::reset()
Chris@0: {
Chris@3:     delete[] m_history;
Chris@7:     m_histlen = int(round(m_sampleRate * longTermSeconds));
Chris@2:     if (m_histlen < 1) m_histlen = 1;
Chris@2:     m_history = new float[m_histlen];
Chris@7:     for (int i = 0; i < m_histlen; ++i) {
Chris@7:         m_history[i] = 0.f;
Chris@7:     }
Chris@1:     m_histwrite = 0;
Chris@1:     m_histread = 0;
Chris@1: 
Chris@7:     m_sumOfSquaresLongTerm = 0.0;
Chris@7:     m_sumOfSquaresShortTerm = 0.0;
Chris@7:     m_rmsLongTerm = 0.f;
Chris@7:     m_rmsShortTerm = 0.f;
Chris@7:     m_maxRmsLongTerm = 0.f;
Chris@8:     m_maxRmsShortTerm = 0.f;
Chris@1:     m_gain = 1.f;
Chris@0: }
Chris@0: 
Chris@0: void
Chris@0: FlattenDynamics::updateParameters()
Chris@0: {
Chris@1:     if (m_pgain) *m_pgain = m_gain;
Chris@0: }
Chris@0: 
Chris@0: void
Chris@0: FlattenDynamics::runImpl(unsigned long sampleCount)
Chris@0: {
Chris@0:     if (!m_input || !m_output) return;
Chris@0:     updateParameters();
Chris@0: 
Chris@1:     // Adjust gain so that
Chris@1:     // * RMS level of the past N seconds is some fixed R, but
Chris@1:     // * peak level does not clip
Chris@1:     // We aim to take M seconds to move to our target gain
Chris@1: 
Chris@2:     for (int i = 0; i < sampleCount; ++i) {
Chris@1:         m_output[i] = process(m_input[i]);
Chris@0:     }
Chris@0: }
Chris@0: 
Chris@1: float
Chris@1: FlattenDynamics::process(float f)
Chris@1: {
Chris@1:     updateRMS(f);
Chris@2: 
Chris@7:     if (m_rmsLongTerm == 0.f) {
Chris@2:         return f;
Chris@2:     }
Chris@2: 
Chris@10:     if (m_rmsLongTerm >= m_maxRmsLongTerm) {
Chris@7:         m_maxRmsLongTerm = m_rmsLongTerm;
Chris@11:     } else if (m_rmsLongTerm < m_maxRmsLongTerm * rmsMaxDecay) {
Chris@11:         m_maxRmsLongTerm *= rmsMaxDecay;
Chris@5:     }
Chris@5: 
Chris@8:     if (m_rmsShortTerm > m_maxRmsShortTerm) {
Chris@8:         m_maxRmsShortTerm = m_rmsShortTerm;
Chris@8:     }
Chris@8: 
Chris@9:     float fixedGain = targetMaxRMS / m_maxRmsLongTerm;
Chris@8: 
Chris@9:     float frac = m_rmsShortTerm / m_maxRmsShortTerm;
Chris@9: 
Chris@9:     // push up toward top of 0,1 range
Chris@9:     frac = pow(frac, 0.3);
Chris@9: 
Chris@9:     float targetRMS = (frac * m_maxRmsShortTerm);
Chris@9: 
Chris@9:     float targetGain = fixedGain * (targetRMS / m_rmsShortTerm);
Chris@8: 
Chris@3:     if (targetGain > maxGain) {
Chris@3:         targetGain = maxGain;
Chris@3:     }
Chris@7: 
Chris@2:     float catchUpSamples = catchUpSeconds * m_sampleRate;
Chris@2:     // asymptotic, could improve?
Chris@2:     m_gain = m_gain + (targetGain - m_gain) / catchUpSamples;
Chris@7: 
Chris@2:     if (fabsf(f) * m_gain > 1.f) {
Chris@2:         m_gain = 1.f / fabsf(f);
Chris@2:     }
Chris@7: 
Chris@2: //    cerr << "target gain = " << targetGain << ", gain = " << m_gain << endl;
Chris@2:     return f * m_gain;
Chris@1: }
Chris@1: 
Chris@1: void
Chris@1: FlattenDynamics::updateRMS(float f)
Chris@1: {
Chris@11:     // We update the RMS values by maintaining a sum-of-last-n-squares
Chris@11:     // total (which the RMS is the square root of 1/n of) and
Chris@11:     // recording the last n samples of history in a circular
Chris@11:     // buffer. When a sample drops off the start of the history, we
Chris@11:     // remove the square of it from the sum-of-squares total; then we
Chris@11:     // add the square of the new sample.
Chris@11: 
Chris@1:     int nextWrite = (m_histwrite + 1) % m_histlen;
Chris@1: 
Chris@7:     float loseLongTerm = 0.f;
Chris@7:     float loseShortTerm = 0.f;
Chris@1: 
Chris@1:     if (nextWrite == m_histread) {
Chris@1:         // full
Chris@7:         loseLongTerm = m_history[m_histread];
Chris@1:         m_histread = (m_histread + 1) % m_histlen;
Chris@1:     }
Chris@1: 
Chris@7:     int shortTermLength = round(shortTermSeconds * m_sampleRate);
Chris@7:     int shortTermLoseIndex = nextWrite - shortTermLength;
Chris@7:     if (shortTermLoseIndex < 0) {
Chris@7:         shortTermLoseIndex += m_histlen;
Chris@7:     }
Chris@7:     // This depends on history being zero-initialised, to be correct at start:
Chris@7:     loseShortTerm = m_history[shortTermLoseIndex];
Chris@7: 
Chris@1:     m_history[m_histwrite] = f;
Chris@1:     m_histwrite = nextWrite;
Chris@1: 
Chris@2:     int fill = (m_histwrite - m_histread + m_histlen) % m_histlen;
Chris@2: 
Chris@7:     m_sumOfSquaresLongTerm -= loseLongTerm * loseLongTerm;
Chris@7:     m_sumOfSquaresLongTerm += f * f;
Chris@1: 
Chris@7:     m_sumOfSquaresShortTerm -= loseShortTerm * loseShortTerm;
Chris@7:     m_sumOfSquaresShortTerm += f * f;
Chris@7: 
Chris@7:     m_rmsLongTerm = sqrt(m_sumOfSquaresLongTerm / fill);
Chris@7:     m_rmsShortTerm = sqrt(m_sumOfSquaresShortTerm / shortTermLength);
Chris@2: //    cerr << "rms = " << m_rms << " (from " << fill << " samples of " << m_histlen << ", latest " << f << ")" << endl;
Chris@1: }
Chris@1: 
Chris@0: const LADSPA_Descriptor *
Chris@0: ladspa_descriptor(unsigned long ix)
Chris@0: {
Chris@0:     return FlattenDynamics::getDescriptor(ix);
Chris@0: }
Chris@0: