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@17: const float historySeconds = 4.f;
Chris@9: const float catchUpSeconds = 0.2f;
Chris@17: const float targetMaxRMS = 0.05f;
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@15:     ladspaInstantiate,
Chris@15:     ladspaConnectPort,
Chris@15:     ladspaActivate,
Chris@15:     ladspaRun,
Chris@0:     0, // Run adding
Chris@0:     0, // Set run adding gain
Chris@15:     ladspaDeactivate,
Chris@15:     ladspaCleanup
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@17:     m_sumOfSquares(0.f),
Chris@17:     m_rms(0.f),
Chris@17:     m_maxRms(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@15: FlattenDynamics::ladspaInstantiate(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@15: FlattenDynamics::ladspaConnectPort(LADSPA_Handle handle,
Chris@15:                                    unsigned long port, 
Chris@15:                                    LADSPA_Data *location)
Chris@0: {
Chris@0:     FlattenDynamics *flatten = (FlattenDynamics *)handle;
Chris@15:     if (ports[port] & LADSPA_PORT_INPUT) {
Chris@15:         flatten->connectInputPort(Port(port), location);
Chris@15:     } else {
Chris@15:         flatten->connectOutputPort(Port(port), location);
Chris@15:     }
Chris@0: }
Chris@0: 
Chris@0: void
Chris@15: FlattenDynamics::ladspaActivate(LADSPA_Handle handle)
Chris@0: {
Chris@0:     FlattenDynamics *flatten = (FlattenDynamics *)handle;
Chris@0:     flatten->reset();
Chris@0: }
Chris@0: 
Chris@0: void
Chris@15: FlattenDynamics::ladspaRun(LADSPA_Handle handle, unsigned long samples)
Chris@0: {
Chris@0:     FlattenDynamics *flatten = (FlattenDynamics *)handle;
Chris@15:     flatten->process(samples);
Chris@0: }
Chris@0: 
Chris@0: void
Chris@15: FlattenDynamics::ladspaDeactivate(LADSPA_Handle handle)
Chris@0: {
Chris@15:     ladspaActivate(handle); // both functions just reset the plugin
Chris@0: }
Chris@0: 
Chris@0: void
Chris@15: FlattenDynamics::ladspaCleanup(LADSPA_Handle handle)
Chris@0: {
Chris@0:     delete (FlattenDynamics *)handle;
Chris@0: }
Chris@0: 
Chris@0: void
Chris@15: FlattenDynamics::connectInputPort(Port p, const float *location)
Chris@15: {
Chris@15:     const float **ports[PortCount] = {
Chris@15: 	&m_input, 0, 0,
Chris@15:     };
Chris@15: 
Chris@15:     *ports[int(p)] = location;
Chris@15: }
Chris@15: 
Chris@15: void
Chris@15: FlattenDynamics::connectOutputPort(Port p, float *location)
Chris@15: {
Chris@15:     float **ports[PortCount] = {
Chris@15: 	0, &m_output, &m_pgain,
Chris@15:     };
Chris@15: 
Chris@15:     *ports[int(p)] = location;
Chris@15: }
Chris@15: 
Chris@15: void
Chris@0: FlattenDynamics::reset()
Chris@0: {
Chris@3:     delete[] m_history;
Chris@17:     m_histlen = int(round(m_sampleRate * historySeconds));
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@17:     m_sumOfSquares = 0.0;
Chris@17:     m_rms = 0.f;
Chris@17:     m_maxRms = 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@15: FlattenDynamics::process(int sampleCount)
Chris@0: {
Chris@0:     if (!m_input || !m_output) return;
Chris@16: 
Chris@0:     updateParameters();
Chris@0: 
Chris@2:     for (int i = 0; i < sampleCount; ++i) {
Chris@15:         m_output[i] = processSingle(m_input[i]);
Chris@0:     }
Chris@0: }
Chris@0: 
Chris@1: float
Chris@15: FlattenDynamics::processSingle(float f)
Chris@1: {
Chris@1:     updateRMS(f);
Chris@2: 
Chris@17:     if (m_rms == 0.f) {
Chris@2:         return f;
Chris@2:     }
Chris@2: 
Chris@17:     if (m_rms >= m_maxRms) {
Chris@17:         m_maxRms = m_rms;
Chris@17:     } else {
Chris@17:         m_maxRms = m_rms + (m_maxRms - m_rms) * rmsMaxDecay;
Chris@5:     }
Chris@5: 
Chris@17:     float targetGain = targetMaxRMS / m_maxRms;
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@17:     float lose = 0.f;
Chris@1: 
Chris@1:     if (nextWrite == m_histread) {
Chris@1:         // full
Chris@17:         lose = m_history[m_histread];
Chris@1:         m_histread = (m_histread + 1) % m_histlen;
Chris@1:     }
Chris@1: 
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@17:     m_sumOfSquares -= lose * lose;
Chris@17:     m_sumOfSquares += f * f;
Chris@1: 
Chris@17:     m_rms = sqrt(m_sumOfSquares / fill);
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: