/* Copyright (C) 2000 Stefan Westerfeld stefan@space.twc.de 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); }