AUD_BandPassReader.cpp

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/*
 * $Id: AUD_BandPassReader.cpp 35141 2011-02-25 10:21:56Z jesterking $
 *
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * Copyright 2009-2011 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 General Public License as published by
 * the Free Software Foundation; either version 2 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Audaspace; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include "AUD_BandPassReader.h"
#include "AUD_Buffer.h"

#include <cstring>
#include <stdio.h>

AUD_BandPassReader::AUD_BandPassReader(AUD_IReader* reader, float low,
                                                                           float high) :
                AUD_EffectReader(reader), m_low(low), m_high(high)
{
        m_buffer = new AUD_Buffer(); AUD_NEW("buffer")
        m_in = new AUD_Buffer(); AUD_NEW("buffer")
        m_out = new AUD_Buffer(); AUD_NEW("buffer")
        m_length = 0;
}

AUD_BandPassReader::~AUD_BandPassReader()
{
        if(m_length != 0)
        {
                fftw_destroy_plan(m_forward);
                fftw_destroy_plan(m_backward);
        }

        delete m_buffer; AUD_DELETE("buffer")
        delete m_in; AUD_DELETE("buffer")
        delete m_out; AUD_DELETE("buffer")
}

AUD_ReaderType AUD_BandPassReader::getType()
{
        return m_reader->getType();
}

void AUD_BandPassReader::read(int & length, sample_t* & buffer)
{
        AUD_Specs specs = m_reader->getSpecs();

        m_reader->read(length, buffer);

        if(length > 0)
        {
                if(length * AUD_SAMPLE_SIZE(specs) > m_buffer->getSize())
                        m_buffer->resize(length * AUD_SAMPLE_SIZE(specs));

                if(length != m_length)
                {
                        if(m_length != 0)
                        {
                                fftw_destroy_plan(m_forward);
                                fftw_destroy_plan(m_backward);
                        }

                        m_length = length;

                        if(m_length * sizeof(double) > m_in->getSize())
                        {
                                m_in->resize(m_length * sizeof(double));
                                m_out->resize((m_length / 2 + 1) * sizeof(fftw_complex));
                        }

                        m_forward = fftw_plan_dft_r2c_1d(m_length,
                                                                                         (double*)m_in->getBuffer(),
                                                                                         (fftw_complex*)m_out->getBuffer(),
                                                                                         FFTW_ESTIMATE);
                        m_backward = fftw_plan_dft_c2r_1d(m_length,
                                                                                          (fftw_complex*)m_out->getBuffer(),
                                                                                          (double*)m_in->getBuffer(),
                                                                                          FFTW_ESTIMATE);
                }

                double* target = (double*) m_in->getBuffer();
                sample_t* target2 = m_buffer->getBuffer();
                fftw_complex* complex = (fftw_complex*) m_out->getBuffer();
                float frequency;

                for(int channel = 0; channel < specs.channels; channel++)
                {
                        for(int i = 0; i < m_length; i++)
                                target[i] = buffer[i * specs.channels + channel];

                        fftw_execute(m_forward);

                        for(int i = 0; i < m_length / 2 + 1; i++)
                        {
                                frequency = i * specs.rate / (m_length / 2.0f + 1.0f);
                                if((frequency < m_low) || (frequency > m_high))
                                        complex[i][0] = complex[i][1] = 0.0;
                        }

                        fftw_execute(m_backward);

                        for(int i = 0; i < m_length; i++)
                                target2[i * specs.channels + channel] = target[i] / m_length;
                }
        }

        buffer = m_buffer->getBuffer();
}