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132 lines
3.2 KiB
132 lines
3.2 KiB
/*
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Copyright (C) 2000 Stefan Westerfeld
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stefan@space.twc.de
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public
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License as published by the Free Software Foundation; either
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version 2 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public License
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along with this library; see the file COPYING.LIB. If not, write to
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the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
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Boston, MA 02110-1301, USA.
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*/
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#include "artsflow.h"
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#include "fft.h"
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#include "stdsynthmodule.h"
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#include <math.h>
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#include <iostream>
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using namespace std;
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using namespace Arts;
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namespace Arts {
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class StereoFFTScope_impl : public StereoFFTScope_skel, public StdSynthModule {
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protected:
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static const unsigned long SAMPLES = 4096;
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vector<float> _scope;
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/*
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* some gcc versions expose ugly behaviour with virtual inheritance:
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* putting window[4096] & inbuffer[4096] here bloats the vtable then,
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* and tells you to recompile with -fhuge-objects ... so allocate them
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* dynamically
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*/
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float *window;
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float *inbuffer;
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unsigned long inbufferpos;
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public:
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void do_fft()
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{
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float out_real[SAMPLES],out_img[SAMPLES];
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arts_fft_float(SAMPLES,0,inbuffer,0,out_real,out_img);
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_scope.clear();
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unsigned int i = 3;
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unsigned int j = 0;
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for(;;) {
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float xrange = 0.0;
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while(j != i)
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{
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xrange += (fabs(out_img[j]) + fabs(out_real[j]))/(float)SAMPLES;
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j++;
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}
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_scope.push_back(xrange);
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if(i == SAMPLES/2) return;
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i += i/2;
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if(i > SAMPLES/2) i = SAMPLES/2;
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}
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}
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void streamInit()
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{
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unsigned long i;
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for(i=0;i<SAMPLES;i++)
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{
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float x = (float)i/(float)SAMPLES;
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window[i] = sin(x*M_PI)*sin(x*M_PI);
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inbuffer[i] = 0;
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}
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do_fft(); // initialize so that we never return an empty scope
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}
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void streamStart()
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{
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inbufferpos = 0;
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}
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vector<float> *scope()
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{
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return new vector<float>(_scope);
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}
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/*
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in audio stream inleft, inright;
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out audio stream outleft, outright;
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*/
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void calculateBlock(unsigned long samples)
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{
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unsigned long i;
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for(i=0;i<samples;i++)
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{
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inbuffer[inbufferpos] =
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(inleft[i] + inright[i])*window[inbufferpos];
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if(++inbufferpos == SAMPLES)
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{
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do_fft();
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inbufferpos = 0;
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}
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/*
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monitoring only tasks can't be done with that StereoEffect
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interface nicely - copy input to output until there is
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something better
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*/
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outleft[i] = inleft[i];
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outright[i] = inright[i];
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}
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}
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/* prevent vtable overflows (see above) */
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StereoFFTScope_impl() {
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window = new float[SAMPLES];
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inbuffer = new float[SAMPLES];
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}
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~StereoFFTScope_impl() {
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delete [] window;
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delete [] inbuffer;
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}
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};
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const unsigned long StereoFFTScope_impl::SAMPLES;
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REGISTER_IMPLEMENTATION(StereoFFTScope_impl);
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}
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