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/*
* $Id$
*
* ***** BEGIN LGPL LICENSE BLOCK *****
*
* Copyright 2009 Jörg Hermann Müller
*
* This file is part of AudaSpace.
*
* AudaSpace is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* AudaSpace is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with AudaSpace. If not, see <http://www.gnu.org/licenses/>.
*
* ***** END LGPL LICENSE BLOCK *****
*/
#include "AUD_EnvelopeReader.h"
#include "AUD_Buffer.h"
#include <cstring>
#include <cmath>
AUD_EnvelopeReader::AUD_EnvelopeReader(AUD_IReader* reader, float attack,
float release, float threshold,
float arthreshold) :
AUD_EffectReader(reader),
m_threshold(threshold)
{
AUD_Specs specs = reader->getSpecs();
int samplesize = AUD_SAMPLE_SIZE(specs);
m_buffer = new AUD_Buffer(); AUD_NEW("buffer")
m_envelopes = new AUD_Buffer(samplesize);
AUD_NEW("buffer")
memset(m_envelopes->getBuffer(), 0, samplesize);
m_bAttack = pow(arthreshold, 1.0/(specs.rate * attack));
m_bRelease = pow(arthreshold, 1.0/(specs.rate * release));
}
AUD_EnvelopeReader::~AUD_EnvelopeReader()
{
delete m_buffer; AUD_DELETE("buffer")
delete m_envelopes; AUD_DELETE("buffer")
}
void AUD_EnvelopeReader::read(int & length, sample_t* & buffer)
{
sample_t* buf;
sample_t* envelopes;
envelopes = m_envelopes->getBuffer();
AUD_Specs specs = m_reader->getSpecs();
m_reader->read(length, buf);
if(m_buffer->getSize() < length * AUD_SAMPLE_SIZE(specs))
m_buffer->resize(length * AUD_SAMPLE_SIZE(specs));
buffer = m_buffer->getBuffer();
sample_t value;
for(int channel = 0; channel < specs.channels; channel++)
{
for(int i = 0; i < length; i++)
{
value = fabs(buf[i * specs.channels + channel]);
if(value < m_threshold)
value = 0.0f;
buffer[i * specs.channels + channel] = envelopes[channel] =
((value > envelopes[channel]) ? m_bAttack : m_bRelease) *
(envelopes[channel] - value) + value;
}
}
}
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