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/*
Copyright (C) 2000 Stefan Westerfeld
[email protected]
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#include "artsflow.h"
#include "fft.h"
#include "stdsynthmodule.h"
#include <math.h>
#include <iostream>
using namespace std;
using namespace Arts;
namespace Arts {
class StereoFFTScope_impl : public StereoFFTScope_skel, public StdSynthModule {
protected:
static const unsigned long SAMPLES = 4096;
vector<float> _scope;
/*
* some gcc versions expose ugly behaviour with virtual inheritance:
* putting window[4096] & inbuffer[4096] here bloats the vtable then,
* and tells you to recompile with -fhuge-objects ... so allocate them
* dynamically
*/
float *window;
float *inbuffer;
unsigned long inbufferpos;
public:
void do_fft()
{
float out_real[SAMPLES],out_img[SAMPLES];
arts_fft_float(SAMPLES,0,inbuffer,0,out_real,out_img);
_scope.clear();
unsigned int i = 3;
unsigned int j = 0;
for(;;) {
float xrange = 0.0;
while(j != i)
{
xrange += (fabs(out_img[j]) + fabs(out_real[j]))/(float)SAMPLES;
j++;
}
_scope.push_back(xrange);
if(i == SAMPLES/2) return;
i += i/2;
if(i > SAMPLES/2) i = SAMPLES/2;
}
}
void streamInit()
{
unsigned long i;
for(i=0;i<SAMPLES;i++)
{
float x = (float)i/(float)SAMPLES;
window[i] = sin(x*M_PI)*sin(x*M_PI);
inbuffer[i] = 0;
}
do_fft(); // initialize so that we never return an empty scope
}
void streamStart()
{
inbufferpos = 0;
}
vector<float> *scope()
{
return new vector<float>(_scope);
}
/*
in audio stream inleft, inright;
out audio stream outleft, outright;
*/
void calculateBlock(unsigned long samples)
{
unsigned long i;
for(i=0;i<samples;i++)
{
inbuffer[inbufferpos] =
(inleft[i] + inright[i])*window[inbufferpos];
if(++inbufferpos == SAMPLES)
{
do_fft();
inbufferpos = 0;
}
/*
monitoring only tasks can't be done with that StereoEffect
interface nicely - copy input to output until there is
something better
*/
outleft[i] = inleft[i];
outright[i] = inright[i];
}
}
/* prevent vtable overflows (see above) */
StereoFFTScope_impl() {
window = new float[SAMPLES];
inbuffer = new float[SAMPLES];
}
~StereoFFTScope_impl() {
delete [] window;
delete [] inbuffer;
}
};
const unsigned long StereoFFTScope_impl::SAMPLES;
REGISTER_IMPLEMENTATION(StereoFFTScope_impl);
}
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