diff options
Diffstat (limited to 'arts/modules/effects/synth_stereo_fir_equalizer_impl.cc')
| -rw-r--r-- | arts/modules/effects/synth_stereo_fir_equalizer_impl.cc | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/arts/modules/effects/synth_stereo_fir_equalizer_impl.cc b/arts/modules/effects/synth_stereo_fir_equalizer_impl.cc new file mode 100644 index 00000000..8125104a --- /dev/null +++ b/arts/modules/effects/synth_stereo_fir_equalizer_impl.cc @@ -0,0 +1,221 @@ +/* + + Copyright (C) 2001-2002 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., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. + + */ + +#include <math.h> + +#include <arts/debug.h> +#include <arts/fft.h> +#include <arts/stdsynthmodule.h> +#include <arts/connect.h> +#include "artsmoduleseffects.h" + +#include <stdio.h> +#include <stdlib.h> + +#include <kglobal.h> +#include <klocale.h> + +using namespace std; +using namespace Arts; + +static inline bool odd(int x) { return ((x & 1) == 1); } + +/* returns a blackman window: x is supposed to be in the interval [0..1] */ +static inline float blackmanWindow(float x) +{ + if(x < 0) return 0; + if(x > 1) return 0; + return 0.42-0.5*cos(M_PI*x*2)+0.08*cos(4*M_PI*x); +} + +void firapprox(double *filter, int filtersize, vector<GraphPoint>& points) +{ + assert((filtersize >= 3) && odd(filtersize)); + + int fft_size = 8; + while(fft_size/2 < filtersize) + fft_size *= 2; + + vector<GraphPoint>::iterator pi = points.begin(); + float lfreq=-2, lval=1.0, rfreq=-1, rval=1.0; + + float *re = (float*) malloc(fft_size * sizeof(float)); + for(int i=0;i<fft_size/2;i++) + { + float freq = float(i)/float(fft_size/2); + + while(freq > rfreq && pi != points.end()) + { + lfreq = rfreq; rfreq = pi->x; + lval = rval; rval = pi->y; + pi++; + } + float pos = (freq-lfreq)/(rfreq-lfreq); + float val = lval*(1.0-pos) + rval*pos; + + //printf("%f %f\n",freq,val); + re[i] = re[fft_size-1-i] = val; + } + + float *filter_re = (float*) malloc(fft_size * sizeof(float)); + float *filter_im = (float*) malloc(fft_size * sizeof(float)); + arts_fft_float (fft_size, 1, re, 0, filter_re, filter_im); + + for(int i=0;i<filtersize;i++) + { + filter[i] = filter_re[(i+fft_size-filtersize/2) & (fft_size-1)] + * blackmanWindow(float(i+1)/float(filtersize+1)); + } + free(re); + free(filter_re); + free(filter_im); +} + +namespace Arts { + +class Synth_STEREO_FIR_EQUALIZER_impl + : virtual public Synth_STEREO_FIR_EQUALIZER_skel, + virtual public StdSynthModule +{ + vector<GraphPoint> _frequencies; + long _taps; + unsigned long bpos; + double filter[256]; + float lbuffer[256]; + float rbuffer[256]; + +public: + Synth_STEREO_FIR_EQUALIZER_impl() + { + _frequencies.push_back(GraphPoint(0.0,1.0)); + _frequencies.push_back(GraphPoint(1.0,1.0)); + _taps = 3; + for(bpos = 0; bpos < 256; bpos++) + lbuffer[bpos] = rbuffer[bpos] = 0.0; + + calcFilter(); + } + vector<GraphPoint> *frequencies() { + return new vector<GraphPoint>(_frequencies); + } + void frequencies(const vector<GraphPoint>& newFrequencies) + { + _frequencies = newFrequencies; + + calcFilter(); + } + long taps() + { + return _taps; + } + void taps(long newTaps) + { + arts_return_if_fail(newTaps >= 3 && newTaps <= 255); + + if(!odd(newTaps)) + newTaps++; + _taps = newTaps; + + calcFilter(); + } + void calcFilter() + { + firapprox(filter, _taps, _frequencies); + } + void calculateBlock(unsigned long samples) + { + for(unsigned i=0;i<samples;i++) + { + double lval = 0.0; + double rval = 0.0; + lbuffer[bpos & 255] = inleft[i]; + rbuffer[bpos & 255] = inright[i]; + + for(int j=0;j<_taps;j++) + { + lval += lbuffer[(bpos-j) & 255] * filter[j]; + rval += rbuffer[(bpos-j) & 255] * filter[j]; + } + outleft[i] = lval; + outright[i] = rval; + bpos++; + } + } +}; + +REGISTER_IMPLEMENTATION(Synth_STEREO_FIR_EQUALIZER_impl); + +class StereoFirEqualizerGuiFactory_impl : public StereoFirEqualizerGuiFactory_skel +{ +public: + Widget createGui(Object equalizer); +}; + +REGISTER_IMPLEMENTATION(StereoFirEqualizerGuiFactory_impl); + +} + +Widget StereoFirEqualizerGuiFactory_impl::createGui(Object object) +{ + KGlobal::locale()->insertCatalogue( "artsmodules" ); + arts_return_val_if_fail(!object.isNull(), Arts::Widget::null()); + + Synth_STEREO_FIR_EQUALIZER equalizer = DynamicCast(object); + arts_return_val_if_fail(!equalizer.isNull(), Arts::Widget::null()); + + VBox vbox; + vbox.show(); + + Graph g; + g.parent(vbox); + g.width(400); + g.height(230); + g.caption(i18n("a graph").utf8().data()); + g.minx(0.0); + g.maxx(1.0); + g.miny(0.0); + g.maxy(1.0); + g.show(); + + GraphLine gline; + gline.graph(g); + vector<GraphPoint> *points = equalizer.frequencies(); + gline.points(*points); + delete points; + gline.color("red"); + gline.editable(true); + + connect(gline,"points_changed", equalizer, "frequencies"); + g._addChild(gline,"gline"); + + SpinBox spinbox; + spinbox.caption(i18n("channels").utf8().data()); + spinbox.min(3); spinbox.max(255); + spinbox.value(equalizer.taps()); + spinbox.parent(vbox); + spinbox.show(); + connect(spinbox,"value_changed", equalizer, "taps"); + vbox._addChild(spinbox,"spinbox"); + vbox._addChild(g,"g"); + + return vbox; +} |