audio-algo-chunkware/simpleSource/SimpleGateProcess.inl
Bojan Marković 4f3794ca80 Sources added
2012-11-24 21:59:58 +01:00

107 lines
3.9 KiB
C++
Executable File

/*
* Simple Gate (runtime function)
*
* File : SimpleGateProcess.inl
* Library : SimpleSource
* Version : 1.12
* Implements : void SimpleGate::process( double &in1, double &in2 )
* void SimpleGate::process( double &in1, double &in2, double keyLinked )
* void SimpleGateRms::process( double &in1, double &in2 )
*
* © 2006, ChunkWare Music Software, OPEN-SOURCE
*
* 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.
*/
#ifndef __SIMPLE_GATE_PROCESS_INL__
#define __SIMPLE_GATE_PROCESS_INL__
namespace chunkware_simple
{
//-------------------------------------------------------------
INLINE void SimpleGate::process( double &in1, double &in2 )
{
// create sidechain
double rect1 = fabs( in1 ); // rectify input
double rect2 = fabs( in2 );
/* if desired, one could use another EnvelopeDetector to smooth
* the rectified signal.
*/
double link = std::max( rect1, rect2 ); // link channels with greater of 2
process( in1, in2, link ); // rest of process
}
//-------------------------------------------------------------
INLINE void SimpleGate::process( double &in1, double &in2, double keyLinked )
{
keyLinked = fabs( keyLinked ); // rectify (just in case)
// threshold
// key over threshold ( 0.0 or 1.0 )
double over = double( keyLinked > thresh_ );
// attack/release
over += DC_OFFSET; // add DC offset to avoid denormal
AttRelEnvelope::run( over, env_ ); // run attack/release
over = env_ - DC_OFFSET; // subtract DC offset
/* REGARDING THE DC OFFSET: In this case, since the offset is added before
* the attack/release processes, the envelope will never fall below the offset,
* thereby avoiding denormals. However, to prevent the offset from causing
* constant gain reduction, we must subtract it from the envelope, yielding
* a minimum value of 0dB.
*/
// output gain
in1 *= over; // apply gain reduction to input
in2 *= over;
}
//-------------------------------------------------------------
INLINE void SimpleGateRms::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
ave_.run( sum, aveOfSqrs_ ); // average of squares
double rms = sqrt( aveOfSqrs_ ); // 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.
*/
SimpleGate::process( in1, in2, rms ); // rest of process
}
} // end namespace chunkware_simple
#endif // end __SIMPLE_GATE_PROCESS_INL__