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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 "LPC_AutoCorrelation.hxx" // imports CLAM LPC_AutoCorrelation Processing declaration
#include "FFT.hxx" // imports CLAM::FFT Processing declaration
#include "LPModel.hxx" // imports CLAM::LPModel ProcessingData declaration
#include "Audio.hxx" // imports CLAM::Audio ProcessingData declaration
#include "Spectrum.hxx" // imports CLAM::Spectrum ProcessingData declaration
#include "SpectrumConfig.hxx" // imports CLAM::Spectrum auxiliar datatypes declaration
#include "WindowGenerator.hxx" // imports CLAM::WindowGenerator Processing declaration
#include "AudioMultiplier.hxx" // imports CLAM::AudioMultiplier Processing declaration
//#include "MultiPlot.hxx" // imports CLAMVM::MultiPlot declaration
//#include "SystemPlots.hxx" // imports CLAMVM::SystemPlots declaration
#include "Err.hxx" // imports CLAM::Err declaration
#include <iostream>
int main( int argc, char** argv )
{
try // note the exception handling
{
// In this example we will learn how to do the following things
// 1) How to generate an analysis window for performing spectral analysis
// 2) How to use one kind of spectral approximation algorithm: the LPC
// and finally, just for fun, we will compute the FT of the same windowed
// audio analyzed by the LPC algorithm, and watch the differences
// The first thing we need is some Audio data to analyze, so we will synthesize
// some simple but non trivial signal
const CLAM::TSize samples=1024; // the number of samples in the audio signal
const CLAM::TData sampleRate=44100.0; // the sample rate of the audio signal
const CLAM::TData sineFreq = 400.0; // frequency of the audio signal sinusoidal
const CLAM::TData offsetFreq = 1200.0;
CLAM::Audio myaudio;
myaudio.SetSize(samples);
myaudio.SetSampleRate( sampleRate );
// Not many bells and whistles here - plain old good sinusoidal synthesis
for ( CLAM::TSize i=0; i<samples; i++ )
myaudio.GetBuffer()[i]=
0.1 +
0.5*sin(2.0*PI*sineFreq*(((float)i)/sampleRate)) +
0.4*sin(2.0*PI*(sineFreq+offsetFreq)*(((float)i)/sampleRate)) +
0.3*sin(2.0*PI*(sineFreq+(2.0*offsetFreq))*(((float)i)/sampleRate)) +
0.2*sin(2.0*PI*(sineFreq+(3.0*offsetFreq))*(((float)i)/sampleRate)) +
0.1*sin(2.0*PI*(sineFreq+(4.0*offsetFreq))*(((float)i)/sampleRate));
// And the next thing we need is to generate the windowing function. Analysis windows
// in CLAM are just Audio's - at the end they are also signals
CLAM::Audio window;
// we set the window size to match that of the signal we just generated
window.SetSize( samples );
// We instantiate a CLAM::WindowGeneratorConfig object that we will
// use for configuring the WindowGenerator Processing1
CLAM::WindowGeneratorConfig wndGenCfg;
// We set the kind of function we want to generate. For this example we will
// use a Blackman-Harris window function with 92dB difference between main and
// side lobes
wndGenCfg.SetType( CLAM::EWindowType::eBlackmanHarris92);
// We set the size of generated windows
wndGenCfg.SetSize( samples );
// We also want the WindowGenerator to normalize generated windows
// as it is meant for spectral analysis
wndGenCfg.SetNormalize( CLAM::EWindowNormalize::eAnalysis );
// We instantiate a WindowGenerator processing
CLAM::WindowGenerator winGen;
// We configure it...
winGen.Configure( wndGenCfg );
// We start it...
winGen.Start();
// And we generate the window calling wingen's Do() method
// passing as well the Audio we created above for holding the
// window function
winGen.Do( window );
// And we stop the processing...
winGen.Stop();
// Third thing: now we must apply the window onto the audio signal
// we want to get analyzed by multiplying the signal by the window
// we instantiate the object we will use for holding the 'windowed'
// signal
CLAM::Audio windowedAudio;
windowedAudio.SetSize( samples );
// The thing that 'multiplies' Audio objects, is obviously enough,
// a Processing called AudioMultiplier
CLAM::AudioMultiplier windowApplier;
// Start, Do and Stop. Note that the parameters in the form
// myAudio window = windowedAudio
windowApplier.Start();
windowApplier.Do( myaudio, window, windowedAudio );
windowApplier.Stop();
// Well, once we have done this essential pre-processing we can try
// to analyze the audio signal. First we will create an object that
// will hold the approximation of signal spectrum - a LPModel instance
CLAM::LPModel lpModel;
// We will try our hand with a polynomial approximation of
// the eleventh order
const unsigned lpcOrder = 11;
// We tell the lpSpectrum object which is the order of the
// approximation we have chosen
lpModel.UpdateModelOrder( lpcOrder );
// and we will set the model spectral range
lpModel.SetSpectralRange( sampleRate / 2 );
// Now it's time to create the LPC_AutoCorrelation Processing config
// object
CLAM::LPCConfig cfg;
// We set the order of the approximation to be computed to the same
// we did for the LPModel object
cfg.SetOrder( lpcOrder );
// We instantiate the processing
CLAM::LPC_AutoCorrelation lpc;
// We configure it...
lpc.Configure( cfg );
// start ...
lpc.Start();
// call its Do() passing the windowed audio data and the LPModel
// object where the approximation is to be stored
lpc.Do( windowedAudio, lpModel );
// ... and we finally stop the object
lpc.Stop();
// We setup the flags for the Spectrum representation of the
// information contrived in the LPModel object
CLAM::SpecTypeFlags flags;
// since we just want a Magnitude/Phase floating-point arrays
// representation we deactivate the other representations
flags.bMagPhase=1;
flags.bComplex = 0;
// We instantiate here the Spectrum object we will use to reflect
// LPModel computed information
CLAM::Spectrum lpSpectrum;
lpSpectrum.SetSize( samples/2+1 );
lpSpectrum.SetSpectralRange( sampleRate/2 );
lpSpectrum.SetType( flags );
// We tell the LPModel to transfer its information to the Spectrum
lpModel.ToSpectrum( lpSpectrum );
// We make the magnitude buffer in the Spectrum to be set in logarithmic
// scale
lpSpectrum.ToDB();
// And now it is FFT turn. For details on the following lines refer to
// FFT_Example.cxx file, where they are explained in depth and detail
CLAM::Spectrum ftSpectrum;
ftSpectrum.SetSize( samples/2+1 );
ftSpectrum.SetSpectralRange( sampleRate/2 );
ftSpectrum.SetType( flags );
CLAM::FFTConfig fconfig;
fconfig.SetAudioSize(samples);
CLAM::FFT myfft;
myfft.Configure( fconfig );
myfft.Start();
myfft.Do( windowedAudio, ftSpectrum );
myfft.Stop();
ftSpectrum.ToDB();
/*
// TODO: Port this to qt4
// Now we create the MultiPlot that will hold the drawings
// of the spectrum we have obtained - refer to MultiPlot_example.cxx
// for a detailed explanation on this
CLAMVM::MultiPlot thePlot( "multiplot" );
thePlot.SetLabel( "LP spectrum (white) vs. FT spectrum (green)" );
thePlot.SetPosition( 100, 100 );
thePlot.SetSize( 640, 480 );
thePlot.SetYRange( -120, 20 );
thePlot.SetColor( "LP spectrum", CLAMVM::Color( 200, 200, 200 ) );
thePlot.AddData( "LP spectrum", lpSpectrum.GetMagBuffer(), 0, 22050 );
thePlot.SetColor( "FT spectrum", CLAMVM::Color( 0, 200, 0 ) );
thePlot.AddData( "FT spectrum", ftSpectrum.GetMagBuffer(), 0, 22050 );
CLAMVM::SystemPlots::Display( "multiplot" );
*/
}
catch( CLAM::Err& e ) // we handle here CLAM exceptions
{
e.Print();
exit(-1);
}
catch( std::exception& e ) // we handle here standard library exceptions
{
std::cerr << e.what() << std::endl;
exit( -1 );
}
return 0;
}
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