AudioWindowing.cxx

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/*
 * Copyright (c) 2001-2004 MUSIC TECHNOLOGY GROUP (MTG)
 *                         UNIVERSITAT POMPEU FABRA
 *
 *
 * This program 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.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include "Segment.hxx"
#include "Frame.hxx"
#include "SpectrumConfig.hxx"
#include "AudioWindowing.hxx"
#include "ProcessingFactory.hxx"

namespace CLAM
{

namespace Hidden 
{
        static const char* metadata[] = {
                "key", "AudioWindowing",
                "category", "Analysis",
                "description", "AudioWindowing",
                0
        };
        static FactoryRegistrator<ProcessingFactory, AudioWindowing> reg = metadata;
}

AudioWindowing::~AudioWindowing()
{
}

bool AudioWindowing::ConcreteConfigure(const ProcessingConfig& cfg)
{
        CopyAsConcreteConfig(mConfig,cfg);
 
        if (! ConfigureChildren()) return false;
        ConfigureData();
        return true;
}

bool AudioWindowing::ConfigureChildren()
{
        int windowSize = mConfig.GetWindowSize();
        EWindowType windowType = mConfig.GetWindowType();
        int hopSize = mConfig.GetHopSize();
        int sampleRate = mConfig.GetSamplingRate();
        if (not (windowSize&1))
        {
                AddConfigErrorMessage("FFT Restriction:");
                AddConfigErrorMessage("Window size should be odd.");
                return false;
        }
        // TODO: Review those restriction
        /*
        if (windowSize<2*hopSize+1)
        {
                AddConfigErrorMessage("FFT Restriction:");
                AddConfigErrorMessage("This condition is not met: WindowSize < 2*HopSize+1");
                return false;
        }
        */
        if (not isPowerOfTwo(mConfig.GetFFTSize()))
        {
                AddConfigErrorMessage("FFT Restriction:");
                AddConfigErrorMessage("FFT Size should be a power of two.");
                return false;
        }
        WindowGeneratorConfig windowGeneratorConfig;
        windowGeneratorConfig.SetSize(windowSize);
        windowGeneratorConfig.SetType(windowType);
        if (! mWindowGenerator.Configure(windowGeneratorConfig) )
        {
                AddConfigErrorMessage("Window Generator configuration failed.");
                AddConfigErrorMessage(mWindowGenerator.GetConfigErrorMessage());
                return false;
        }

        CircularShiftConfig circularShiftConfig;
        circularShiftConfig.SetAmount(-((windowSize-1)/TData(2))); 
        if (! mCircularShift.Configure(circularShiftConfig) )
        {
                AddConfigErrorMessage("Circular Shift configuration failed.");
                AddConfigErrorMessage(mCircularShift.GetConfigErrorMessage());
                return false;
        }

        return true;
}

void AudioWindowing::ConfigureData()
{
        mInput.SetSize(mConfig.GetWindowSize()-1);
        mInput.SetHop(mConfig.GetHopSize());

        mWindow.SetSize(mConfig.GetWindowSize());
        
        /*Window is generated and data is kept in internal member mWindow*/
        mWindowGenerator.Do(mWindow);
        
        /*Leaving out last sample of odd-sized window*/
        mWindow.SetSize(mWindow.GetSize()-1);

        /* Adding zero padding to windowing function */
        mWindow.SetSize(mConfig.GetFFTSize());
}

void AudioWindowing::AttachChildren()
{
        mWindowGenerator.SetParent(this);
        mAudioProduct.SetParent(this);
        mCircularShift.SetParent(this);
}

bool AudioWindowing::Do(void)
{
        bool result =  Do(mInput.GetAudio(),mOutput.GetData());

        mInput.Consume();
        mOutput.Produce();

        return result;
}

bool AudioWindowing::Do(const Audio& in,Audio& out)
{
        in.GetAudioChunk(0,in.GetSize() ,out,true );
        out.SetSampleRate(mConfig.GetSamplingRate());

        // Zero padding
        out.SetSize(mConfig.GetFFTSize());
        
        // Windowing
        if (mConfig.GetWindowType()!=EWindowType::eNone )
                mAudioProduct.Do(out, mWindow, out);
        
        // Half Window Shift
        if (mConfig.GetDoHalfWindowShift())
                mCircularShift.Do(out,out);


        return true;
}



} // namespace CLAM

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