audio-algo-chunkware/audio/algo/chunkware/CompressorRms.cpp

67 lines
2.5 KiB
C++

/**
* @author Bojan MARKOVIC
* @author Edouard DUPIN
* @copyright 2006, ChunkWare Music Software, OPEN-SOURCE
* @license BSD-1 (see license file)
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* * The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#include <audio/algo/chunkware/CompressorRms.h>
audio::algo::chunkware::CompresssorRms::CompresssorRms() :
m_averager(5.0),
m_averageSuares(DC_OFFSET) {
}
void audio::algo::chunkware::CompresssorRms::setSampleRate(double sampleRate) {
audio::algo::chunkware::Compresssor::setSampleRate(sampleRate);
m_averager.setSampleRate(sampleRate);
}
void audio::algo::chunkware::CompresssorRms::setWindow(double ms) {
m_averager.setTc(ms);
}
void audio::algo::chunkware::CompresssorRms::initRuntime() {
audio::algo::chunkware::Compresssor::initRuntime();
m_averageSuares = DC_OFFSET;
}
void audio::algo::chunkware::CompresssorRms::process(double &in1, double &in2) {
// create sidechain
double inSq1 = in1 * in1; // square input
double inSq2 = in2 * in2;
double sum = inSq1 + inSq2; // power summing
sum += DC_OFFSET; // DC offset, to prevent denormal
m_averager.run(sum, m_averageSuares); // average of squares
double rms = sqrt(m_averageSuares); // rms (sort of ...)
/* REGARDING THE RMS AVERAGER: Ok, so this isn't a REAL RMS
* calculation. A true RMS is an FIR moving average. This
* approximation is a 1-pole IIR. Nonetheless, in practice,
* and in the interest of simplicity, this method will suffice,
* giving comparable results.
*/
// rest of process
Compresssor::process(in1, in2, rms);
}