+++ /dev/null
-/************************************************************************
- ************************************************************************
- FAUST library file
- Copyright (C) 2003-2011 GRAME, Centre National de Creation Musicale
- ---------------------------------------------------------------------
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU Lesser General Public License as
- published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA.
- ************************************************************************
- ************************************************************************/
-
-declare name "MaxMSP compatibility Library";
-declare author "GRAME";
-declare copyright "GRAME";
-declare version "1.0";
-declare license "LGPL";
-
-import("music.lib");
-
-
-atodb = db2lin;
-
-//-------------------------------------------------------------------------
-//
-// Implementation of MaxMSP filtercoeff
-//
-// from : Cookbook formulae for audio EQ biquad filter coefficients
-// by : Robert Bristow-Johnson <rbj@audioimagination.com>
-// URL : http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt
-//
-//-------------------------------------------------------------------------
-
-filtercoeff(f0, dBgain, Q) = environment
-{
- //----------------------------------------
- // biquad coeffs for various filters
- // usage : filtercoeff(f0, dBgain, Q).LPF
- //----------------------------------------
-
- LPF = rbjcoef( a0, a1, a2, b0, b1, b2 )
- with {
- b0 = (1 - cos(w0))/2;
- b1 = 1 - cos(w0);
- b2 = (1 - cos(w0))/2;
- a0 = 1 + alpha;
- a1 = -2*cos(w0);
- a2 = 1 - alpha;
- };
-
- HPF = rbjcoef( a0, a1, a2, b0, b1, b2 )
- with {
- b0 = (1 + cos(w0))/2;
- b1 = -1 - cos(w0);
- b2 = (1 + cos(w0))/2;
- a0 = 1 + alpha;
- a1 = -2*cos(w0);
- a2 = 1 - alpha;
- };
-
- BPF = rbjcoef( a0, a1, a2, b0, b1, b2 ) // constant 0 dB peak gain
- with {
- b0 = alpha;
- b1 = 0;
- b2 = -alpha;
- a0 = 1 + alpha;
- a1 = -2*cos(w0);
- a2 = 1 - alpha;
- };
-
- notch = rbjcoef( a0, a1, a2, b0, b1, b2 )
- with {
- b0 = 1;
- b1 = -2*cos(w0);
- b2 = 1;
- a0 = 1 + alpha;
- a1 = -2*cos(w0);
- a2 = 1 - alpha;
- };
-
- APF = rbjcoef( a0, a1, a2, b0, b1, b2 )
- with {
- b0 = 1 - alpha;
- b1 = -2*cos(w0);
- b2 = 1 + alpha;
- a0 = 1 + alpha;
- a1 = -2*cos(w0);
- a2 = 1 - alpha;
- };
-
- peakingEQ = rbjcoef( a0, a1, a2, b0, b1, b2 )
- with {
- b0 = 1 + alpha*A;
- b1 = -2*cos(w0);
- b2 = 1 - alpha*A;
- a0 = 1 + alpha/A;
- a1 = -2*cos(w0);
- a2 = 1 - alpha/A;
- };
-
- peakNotch = rbjcoef( a0, a1, a2, b0, b1, b2 )
- with {
- b0 = 1 + alpha*G;
- b1 = -2*cos(w0);
- b2 = 1 - alpha*G;
- a0 = 1 + alpha/G;
- a1 = -2*cos(w0);
- a2 = 1 - alpha/G;
- };
-
- lowShelf = rbjcoef( a0, a1, a2, b0, b1, b2 )
- with {
- b0 = A*( (A+1) - (A-1)*cos(w0) + 2*sqrt(A)*alpha );
- b1 = 2*A*( (A-1) - (A+1)*cos(w0) );
- b2 = A*( (A+1) - (A-1)*cos(w0) - 2*sqrt(A)*alpha );
- a0 = (A+1) + (A-1)*cos(w0) + 2*sqrt(A)*alpha;
- a1 = -2*( (A-1) + (A+1)*cos(w0) );
- a2 = (A+1) + (A-1)*cos(w0) - 2*sqrt(A)*alpha;
- };
-
- highShelf = rbjcoef( a0, a1, a2, b0, b1, b2 )
- with {
- b0 = A*( (A+1) + (A-1)*cos(w0) + 2*sqrt(A)*alpha );
- b1 = -2*A*( (A-1) + (A+1)*cos(w0) );
- b2 = A*( (A+1) + (A-1)*cos(w0) - 2*sqrt(A)*alpha );
- a0 = (A+1) - (A-1)*cos(w0) + 2*sqrt(A)*alpha;
- a1 = 2*( (A-1) - (A+1)*cos(w0) );
- a2 = (A+1) - (A-1)*cos(w0) - 2*sqrt(A)*alpha;
- };
-
- // --------------------- implementation ------------------------------
-
- // convert rbj coeffs to biquad coeffs
- rbjcoef(a0,a1,a2,b0,b1,b2) = (b0/a0, b1/a0, b2/a0,-a1/a0,-a2/a0);
-
- // common values
-// alpha = sin(w0)/(2*Q);
-// w0 = 2*PI*f0/Fs;
- alpha = sin(w0)/(2*max(0.001,Q));
- w0 = 2*PI*max(0,f0)/Fs;
- Fs = SR;
- A = 10^(dBgain/40); // (for peaking and shelving EQ filters only)
- G = sqrt(max(0.00001, dBgain)); // When gain is a linear values (i.e. not in dB)
-};
-
-
-//-------------------------------------------------------------------------
-// Implementation of MaxMSP biquad~
-// y[n] = a0 * x[n] + a1 * x[n-1] + a2 * x[n-2] + b1 * y[n-1] + b2 * y[n-2]
-//-------------------------------------------------------------------------
-
-biquad(x,a0,a1,a2,b1,b2) = x : conv3(a0, a1, a2) : + ~ conv2(b1, b2)
- with {
- conv2(c0,c1,x) = c0*x+c1*x';
- conv3(c0,c1,c2,x) = c0*x+c1*x'+c2*x'';
- };
-
-
-//-------------------------------------------------------------------------
-//
-// Filters using filtercoeff and biquad
-//
-//-------------------------------------------------------------------------
-
-
-// Low Pass Filter
-LPF(x, f0, gain, Q) = x , filtercoeff(f0,gain,Q).LPF : biquad;
-
-// High Pass Filter
-HPF(x, f0, gain, Q) = x , filtercoeff(f0,gain,Q).HPF : biquad;
-
-// Band Pass Filter
-BPF(x, f0, gain, Q) = x , filtercoeff(f0,gain,Q).BPF : biquad;
-
-// notch Filter
-notch(x, f0, gain, Q) = x , filtercoeff(f0,gain,Q).notch : biquad;
-
-// All Pass Filter
-APF(x, f0, gain, Q) = x , filtercoeff(f0,gain,Q).APF : biquad;
-
-// ????
-peakingEQ(x, f0, gain, Q) = x , filtercoeff(f0,gain,Q).peakingEQ : biquad;
-
-// Max peakNotch is like peakingEQ but with a linear gain
-peakNotch(x, f0, gain, Q) = x , filtercoeff(f0,gain,Q).peakNotch : biquad;
-
-// ????
-lowShelf(x, f0, gain, Q) = x , filtercoeff(f0,gain,Q).lowShelf : biquad;
-
-// ????
-highShelf(x, f0, gain, Q) = x , filtercoeff(f0,gain,Q).highShelf : biquad;
-
-
-
-
-//-------------------------------------------------------------------------
-// Implementation of Max/MSP line~. Generate signal ramp or envelope
-//
-// USAGE : line(value, time)
-// value : the desired output value
-// time : the interpolation time to reach this value (in milliseconds)
-//
-// NOTE : the interpolation process is restarted every time the desired
-// output value changes. The interpolation time is sampled only then.
-//-------------------------------------------------------------------------
-
-line (value, time) = state ~ ( _ , _ ) : ! , _
- with {
- state (t , c) = nt , if( nt <= 0 , value , c + (value - c) / nt)
- with {
- nt = if( value != value' , samples, t - 1) ;
- samples = time * SR / 1000.0 ;
- } ;
- } ;
-
-
projects / Faustine.git / blobdiff