Index: src/Makefile.am
===================================================================
--- src/Makefile.am	(revision d9c45df5930c9964f82363e4ea88a4a9c4cda732)
+++ src/Makefile.am	(revision a4364b83d213f0c725b47bacbea5bfa39f798f91)
@@ -1,5 +1,4 @@
 noinst_HEADERS = \
-	aubio_priv.h \
-	temporal/filter_priv.h
+	aubio_priv.h
 
 nobase_pkginclude_HEADERS = \
Index: src/pitch/pitchdetection.c
===================================================================
--- src/pitch/pitchdetection.c	(revision d9c45df5930c9964f82363e4ea88a4a9c4cda732)
+++ src/pitch/pitchdetection.c	(revision a4364b83d213f0c725b47bacbea5bfa39f798f91)
@@ -20,4 +20,5 @@
 #include "fvec.h"
 #include "cvec.h"
+#include "lvec.h"
 #include "spectral/phasevoc.h"
 #include "mathutils.h"
@@ -104,5 +105,5 @@
       p->fftgrain = new_cvec(bufsize, channels);
       p->mcomb    = new_aubio_pitchmcomb(bufsize,hopsize,channels,samplerate);
-      p->filter   = new_aubio_cdsgn_filter(samplerate, channels);
+      p->filter   = new_aubio_filter_cdsgn (samplerate, channels);
       p->callback = aubio_pitchdetection_mcomb;
       break;
Index: src/temporal/adesign.c
===================================================================
--- src/temporal/adesign.c	(revision d9c45df5930c9964f82363e4ea88a4a9c4cda732)
+++ src/temporal/adesign.c	(revision a4364b83d213f0c725b47bacbea5bfa39f798f91)
@@ -1,57 +1,159 @@
 /*
-   Copyright (C) 2003-2007 Paul Brossier
 
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2 of the License, or
-   (at your option) any later version.
+  Copyright (C) 2003-2009 Paul Brossier <piem@aubio.org>
 
-   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 General Public License for more details.
+  This file is part of aubio.
 
-   You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+  aubio is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  aubio 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 General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with aubio.  If not, see <http://www.gnu.org/licenses/>.
 
 */
-
 
 #include "aubio_priv.h"
 #include "types.h"
 #include "fvec.h"
+#include "lvec.h"
 #include "temporal/filter.h"
-#include "temporal/filter_priv.h"
 #include "temporal/adesign.h"
 
-aubio_filter_t * new_aubio_adsgn_filter(uint_t samplerate, uint_t channels) {
-  aubio_filter_t * f = new_aubio_filter(samplerate, 7, channels);
-  lsmp_t * a = f->a->data[0];
-  lsmp_t * b = f->b->data[0];
-  /* uint_t l; */
-  /* for now, 44100, adsgn */
-  a[0] =  1.00000000000000000000000000000000000000000000000000000; 
-  a[1] = -4.01957618111583236952810693765059113502502441406250000; 
-  a[2] =  6.18940644292069386267485242569819092750549316406250000; 
-  a[3] = -4.45319890354411640487342083360999822616577148437500000; 
-  a[4] =  1.42084294962187751565352300531230866909027099609375000; 
-  a[5] = -0.14182547383030480458998567883099894970655441284179688; 
-  a[6] =  0.00435117723349511334451911181986361043527722358703613; 
-  b[0] =  0.25574112520425740235907596797915175557136535644531250;
-  b[1] = -0.51148225040851391653973223583307117223739624023437500;
-  b[2] = -0.25574112520426162120656954357400536537170410156250000;
-  b[3] =  1.02296450081703405032840237254276871681213378906250000;
-  b[4] = -0.25574112520426051098354491841746494174003601074218750;
-  b[5] = -0.51148225040851369449512731080176308751106262207031250;
-  b[6] =  0.25574112520425729133677350546349771320819854736328125;
-  /* DBG: filter coeffs at creation time */
-  /*
-  for (l=0; l<f->order; l++){
-    AUBIO_DBG("a[%d]=\t%1.16f\tb[%d]=\t%1.16f\n",l,a[l],l,b[l]);
+void aubio_filter_set_adsgn (aubio_filter_t * f) {
+
+  uint_t samplerate = aubio_filter_get_samplerate (f);
+  lvec_t *bs = aubio_filter_get_feedforward (f);
+  lvec_t *as = aubio_filter_get_feedback (f);
+  lsmp_t *b = bs->data[0], *a = as->data[0];
+  uint_t order = aubio_filter_get_order (f);
+
+  if ( order != 7 ) {
+    AUBIO_ERROR ( "order of A-weighting filter must be 7, not %d\n", order );
+    return;
   }
-  */
-  f->a->data[0] = a;
-  f->b->data[0] = b;
+
+  /* select coefficients according to sampling frequency */
+  switch ( samplerate ) {
+
+    case 8000:
+      b[0] =  6.306209468238731519207362907764036208391189575195312500e-01;
+      b[1] = -1.261241893647746525886077506584115326404571533203125000e+00;
+      b[2] = -6.306209468238730408984338282607495784759521484375000000e-01;
+      b[3] =  2.522483787295493051772155013168230652809143066406250000e+00;
+      b[4] = -6.306209468238730408984338282607495784759521484375000000e-01;
+      b[5] = -1.261241893647746525886077506584115326404571533203125000e+00;
+      b[6] =  6.306209468238731519207362907764036208391189575195312500e-01;
+      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
+      a[1] = -2.128467193009123015201566886389628052711486816406250000e+00;
+      a[2] =  2.948668980101234460278192273108288645744323730468750000e-01;
+      a[3] =  1.824183830735050637628091863007284700870513916015625000e+00;
+      a[4] = -8.056628943119792385374466903158463537693023681640625000e-01;
+      a[5] = -3.947497982842933517133587884018197655677795410156250000e-01;
+      a[6] =  2.098548546080332977137317129745497368276119232177734375e-01;
+      break;
+
+    case 16000:
+      b[0] =  5.314898298235570806014038680586963891983032226562500000e-01;
+      b[1] = -1.062979659647114161202807736117392778396606445312500000e+00;
+      b[2] = -5.314898298235570806014038680586963891983032226562500000e-01;
+      b[3] =  2.125959319294228322405615472234785556793212890625000000e+00;
+      b[4] = -5.314898298235570806014038680586963891983032226562500000e-01;
+      b[5] = -1.062979659647114161202807736117392778396606445312500000e+00;
+      b[6] =  5.314898298235570806014038680586963891983032226562500000e-01;
+      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
+      a[1] = -2.867832572992162987191022693878039717674255371093750000e+00;
+      a[2] =  2.221144410202312347024644623161293566226959228515625000e+00;
+      a[3] =  4.552683347886614662058946123579517006874084472656250000e-01;
+      a[4] = -9.833868636162828025248927588108927011489868164062500000e-01;
+      a[5] =  5.592994142413361402521587706360151059925556182861328125e-02;
+      a[6] =  1.188781038285612462468421313133148942142724990844726562e-01;
+      break;
+
+    case 22050:
+      b[0] =  4.492998504299193784916610638902056962251663208007812500e-01;
+      b[1] = -8.985997008598388680056245902960654348134994506835937500e-01;
+      b[2] = -4.492998504299192674693586013745516538619995117187500000e-01;
+      b[3] =  1.797199401719677958055854105623438954353332519531250000e+00;
+      b[4] = -4.492998504299192674693586013745516538619995117187500000e-01;
+      b[5] = -8.985997008598388680056245902960654348134994506835937500e-01;
+      b[6] =  4.492998504299193784916610638902056962251663208007812500e-01;
+      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
+      a[1] = -3.229078805225074955131958631682209670543670654296875000e+00;
+      a[2] =  3.354494881236033787530459449044428765773773193359375000e+00;
+      a[3] = -7.317843680657351024265722116979304701089859008789062500e-01;
+      a[4] = -6.271627581807257545420952737913466989994049072265625000e-01;
+      a[5] =  1.772142005020879151899748649157118052244186401367187500e-01;
+      a[6] =  5.631716697383508385410522123493137769401073455810546875e-02;
+      break;
+
+    case 44100:
+      b[0] =  2.55741125204257513381378430494805797934532165527343750e-01;
+      b[1] = -5.114822504085150267627568609896115958690643310546875000e-01;
+      b[2] = -2.557411252042575133813784304948057979345321655273437500e-01;
+      b[3] =  1.022964500817030053525513721979223191738128662109375000e+00;
+      b[4] = -2.557411252042575133813784304948057979345321655273437500e-01;
+      b[5] = -5.114822504085150267627568609896115958690643310546875000e-01;
+      b[6] =  2.557411252042575133813784304948057979345321655273437500e-01;
+      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
+      a[1] = -4.019576181115832369528106937650591135025024414062500000e+00;
+      a[2] =  6.189406442920693862674852425698190927505493164062500000e+00;
+      a[3] = -4.453198903544116404873420833609998226165771484375000000e+00;
+      a[4] =  1.420842949621876627475103305187076330184936523437500000e+00;
+      a[5] = -1.418254738303044160119270600262098014354705810546875000e-01;
+      a[6] =  4.351177233495117681327801761881346465088427066802978516e-03;
+
+    case 96000:
+      b[0] =  9.951898975972744976203898659150581806898117065429687500e-02;
+      b[1] = -1.990379795194548995240779731830116361379623413085937500e-01;
+      b[2] = -9.951898975972744976203898659150581806898117065429687500e-02;
+      b[3] =  3.980759590389097990481559463660232722759246826171875000e-01;
+      b[4] = -9.951898975972744976203898659150581806898117065429687500e-02;
+      b[5] = -1.990379795194548995240779731830116361379623413085937500e-01;
+      b[6] =  9.951898975972744976203898659150581806898117065429687500e-02;
+      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
+      a[1] = -4.802203044225376693532325589330866932868957519531250000e+00;
+      a[2] =  9.401807218627226347962277941405773162841796875000000000e+00;
+      a[3] = -9.566143943569164420637207513209432363510131835937500000e+00;
+      a[4] =  5.309775930392619081032989925006404519081115722656250000e+00;
+      a[5] = -1.517333360452622237346531619550660252571105957031250000e+00;
+      a[6] =  1.740971994228911745583587844521389342844486236572265625e-01;
+      break;
+
+    case 192000:
+      b[0] =  3.433213424548713782469278044118254911154508590698242188e-02;
+      b[1] = -6.866426849097426177159775306790834292769432067871093750e-02;
+      b[2] = -3.433213424548714476358668434841092675924301147460937500e-02;
+      b[3] =  1.373285369819485235431955061358166858553886413574218750e-01;
+      b[4] = -3.433213424548714476358668434841092675924301147460937500e-02;
+      b[5] = -6.866426849097426177159775306790834292769432067871093750e-02;
+      b[6] =  3.433213424548713782469278044118254911154508590698242188e-02;
+      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
+      a[1] = -5.305923689674640009172890131594613194465637207031250000e+00;
+      a[2] =  1.165952437466175695135461864992976188659667968750000000e+01;
+      a[3] = -1.357560092700591525272102444432675838470458984375000000e+01;
+      a[4] =  8.828906932824192921316353022120893001556396484375000000e+00;
+      a[5] = -3.039490120988216581565666274400427937507629394531250000e+00;
+      a[6] =  4.325834301870381537469256727490574121475219726562500000e-01;
+      break;
+
+    default: 
+      AUBIO_ERROR ( "sampling rate of A-weighting filter is %d, should be one of\
+ 8000, 16000, 22050, 44100, 96000, 192000.\n",  samplerate );
+      break;
+
+  }
+
+}
+
+aubio_filter_t * new_aubio_filter_adsgn (uint_t samplerate, uint_t channels) {
+  aubio_filter_t * f = new_aubio_filter (samplerate, 7, channels);
+  aubio_filter_set_adsgn (f);
   return f;
 }
Index: src/temporal/adesign.h
===================================================================
--- src/temporal/adesign.h	(revision d9c45df5930c9964f82363e4ea88a4a9c4cda732)
+++ src/temporal/adesign.h	(revision a4364b83d213f0c725b47bacbea5bfa39f798f91)
@@ -1,18 +1,19 @@
 /*
-   Copyright (C) 2003-2007 Paul Brossier
+  Copyright (C) 2003-2009 Paul Brossier <piem@aubio.org>
 
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2 of the License, or
-   (at your option) any later version.
+  This file is part of aubio.
 
-   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 General Public License for more details.
+  aubio is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
 
-   You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+  aubio 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 General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with aubio.  If not, see <http://www.gnu.org/licenses/>.
 
 */
@@ -23,7 +24,28 @@
 /** \file
 
-  Create a new A-design filter 
+  Create an A-weighting filter
+  
+  This file creates an A-weighting digital filter, which reduces low and high
+  frequencies and enhance the middle ones to reflect the ability of the human
+  hearing.
+  
+  The implementation is based on the following standard:
 
-  This file creates an IIR filter object with A-design coefficients.
+    - IEC/CD 1672: Electroacoustics-Sound Level Meters, IEC, Geneva, Nov.  1996,
+  for A- and C-weighting filters.
+  
+  See also:
+  
+    - <a href="http://en.wikipedia.org/wiki/A-weighting">A-Weighting on
+  Wikipedia</a>
+    - <a href="http://en.wikipedia.org/wiki/Weighting_filter">Weighting filter on
+  Wikipedia</a>
+    - <a href="http://www.mathworks.com/matlabcentral/fileexchange/69">Christophe
+  Couvreur's 'octave' toolbox</a>
+  
+  The coefficients in this file have been computed using Christophe Couvreur's
+  scripts in octave 3.0 (debian package 1:3.0.5-6+b2 with octave-signal
+  1.0.9-1+b1 on i386), with <pre> [b, a] = adsign(1/Fs) </pre> for various
+  sampling frequencies.
 
 */
@@ -35,14 +57,19 @@
 /** create new A-design filter
 
-  \param samplerate sampling-rate of the signal to filter 
+  \param samplerate sampling frequency of the signal to filter. Should be one of 
+  8000, 16000, 22050, 44100, 96000, 192000.
   \param channels number of channels to allocate
 
+  \return a new filter object
+
 */
-aubio_filter_t * new_aubio_adsgn_filter(uint_t samplerate, uint_t channels);
+aubio_filter_t * new_aubio_filter_adsgn (uint_t samplerate, uint_t channels);
 
-/** filter input vector (in-place) */
-#define aubio_adsgn_filter_do aubio_filter_do
-/** delete a-design filter object */
-#define del_aubio_adsgn_filter del_aubio_filter
+/** set feedback and feedforward coefficients of a A-weighting filter
+
+  \param f filter object to get coefficients from
+
+*/
+void aubio_filter_set_adsgn (aubio_filter_t *f);
 
 #ifdef __cplusplus
Index: src/temporal/cdesign.c
===================================================================
--- src/temporal/cdesign.c	(revision d9c45df5930c9964f82363e4ea88a4a9c4cda732)
+++ src/temporal/cdesign.c	(revision a4364b83d213f0c725b47bacbea5bfa39f798f91)
@@ -1,53 +1,135 @@
 /*
-   Copyright (C) 2003-2007 Paul Brossier
+  Copyright (C) 2003-2009 Paul Brossier <piem@aubio.org>
 
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2 of the License, or
-   (at your option) any later version.
+  This file is part of aubio.
 
-   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 General Public License for more details.
+  aubio is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
 
-   You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+  aubio 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 General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with aubio.  If not, see <http://www.gnu.org/licenses/>.
 
 */
-
 
 #include "aubio_priv.h"
 #include "types.h"
 #include "fvec.h"
+#include "lvec.h"
 #include "temporal/filter.h"
-#include "temporal/filter_priv.h"
-#include "temporal/adesign.h"
+#include "temporal/cdesign.h"
 
-aubio_filter_t * new_aubio_cdsgn_filter(uint_t samplerate, uint_t channels) {
+void aubio_filter_set_cdsgn (aubio_filter_t * f) {
+
+  uint_t samplerate = aubio_filter_get_samplerate (f);
+  lvec_t * bs = aubio_filter_get_feedforward (f);
+  lvec_t * as = aubio_filter_get_feedback (f);
+  lsmp_t *b = bs->data[0], *a = as->data[0];
+  uint_t order = aubio_filter_get_order (f);
+
+  if ( order != 5 ) {
+    AUBIO_ERROR ( "order of C-weighting filter must be 5, not %d\n", order );
+    return;
+  }
+
+  /* select coefficients according to sampling frequency */
+  switch ( samplerate ) {
+
+    case 8000:
+      b[0] =  6.782173932405135552414776611840352416038513183593750000e-01;
+      b[1] =  0.000000000000000000000000000000000000000000000000000000e+00;
+      b[2] = -1.356434786481027110482955322368070483207702636718750000e+00;
+      b[3] =  0.000000000000000000000000000000000000000000000000000000e+00;
+      b[4] =  6.782173932405135552414776611840352416038513183593750000e-01;
+      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
+      a[1] = -6.589092811505605773447769024642184376716613769531250000e-01;
+      a[2] = -1.179445664897062595599663836765103042125701904296875000e+00;
+      a[3] =  4.243329729632123736848825501510873436927795410156250000e-01;
+      a[4] =  4.147270002091348328754349950031610205769538879394531250e-01;
+      break;
+
+    case 16000:
+      b[0] =  4.971057193673903418229542694461997598409652709960937500e-01;
+      b[1] =  0.000000000000000000000000000000000000000000000000000000e+00;
+      b[2] = -9.942114387347806836459085388923995196819305419921875000e-01;
+      b[3] =  0.000000000000000000000000000000000000000000000000000000e+00;
+      b[4] =  4.971057193673903418229542694461997598409652709960937500e-01;
+      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
+      a[1] = -1.162322939286873690889478893950581550598144531250000000e+00;
+      a[2] = -4.771961355734982701548574368644040077924728393554687500e-01;
+      a[3] =  4.736145114694704227886745684372726827859878540039062500e-01;
+      a[4] =  1.660337524309875301131711466950946487486362457275390625e-01;
+      break;
+
+    case 22050:
+      b[0] =  4.033381299002754549754001800465630367398262023925781250e-01;
+      b[1] =  0.000000000000000000000000000000000000000000000000000000e+00;
+      b[2] = -8.066762598005509099508003600931260734796524047851562500e-01;
+      b[3] =  0.000000000000000000000000000000000000000000000000000000e+00;
+      b[4] =  4.033381299002754549754001800465630367398262023925781250e-01;
+      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
+      a[1] = -1.449545371157945350404361306573264300823211669921875000e+00;
+      a[2] = -1.030104190885922088583015465701464563608169555664062500e-02;
+      a[3] =  3.881857047554073680828423675848171114921569824218750000e-01;
+      a[4] =  7.171589940116777917022972133054281584918498992919921875e-02;
+      break;
+
+    case 44100:
+      b[0] =  2.170085619492190254220531642204150557518005371093750000e-01;
+      b[1] =  0.000000000000000000000000000000000000000000000000000000e+00;
+      b[2] = -4.340171238984380508441063284408301115036010742187500000e-01;
+      b[3] =  0.000000000000000000000000000000000000000000000000000000e+00;
+      b[4] =  2.170085619492190254220531642204150557518005371093750000e-01;
+      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
+      a[1] = -2.134674963687040794013682898366823792457580566406250000e+00;
+      a[2] =  1.279333533236062692139967111870646476745605468750000000e+00;
+      a[3] = -1.495598460893957093453821016737492755055427551269531250e-01;
+      a[4] =  4.908700174624683852664386307651511742733418941497802734e-03;
+      break;
+
+    case 96000:
+      b[0] =  8.182864044979756834585771230194950476288795471191406250e-02;
+      b[1] =  0.000000000000000000000000000000000000000000000000000000e+00;
+      b[2] = -1.636572808995951366917154246038990095257759094238281250e-01;
+      b[3] =  0.000000000000000000000000000000000000000000000000000000e+00;
+      b[4] =  8.182864044979756834585771230194950476288795471191406250e-02;
+      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
+      a[1] = -2.856378516857566829401093855267390608787536621093750000e+00;
+      a[2] =  2.897640237559524045707348705036565661430358886718750000e+00;
+      a[3] = -1.225265958339703198376469117647502571344375610351562500e+00;
+      a[4] =  1.840048283551226071530493300087982788681983947753906250e-01;
+      break;
+
+    case 192000:
+      b[0] =  2.784755468532278815940728122768632601946592330932617188e-02;
+      b[1] =  0.000000000000000000000000000000000000000000000000000000e+00;
+      b[2] = -5.569510937064557631881456245537265203893184661865234375e-02;
+      b[3] =  0.000000000000000000000000000000000000000000000000000000e+00;
+      b[4] =  2.784755468532278815940728122768632601946592330932617188e-02;
+      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
+      a[1] = -3.333298856144166322224009491037577390670776367187500000e+00;
+      a[2] =  4.111467536240339448738723149290308356285095214843750000e+00;
+      a[3] = -2.222889041651291641699117462849244475364685058593750000e+00;
+      a[4] =  4.447204118126878991112960193277103826403617858886718750e-01;
+      break;
+
+    default:
+      AUBIO_ERROR ( "sampling rate of C-weighting filter is %d, should be one of\
+ 8000, 16000, 22050, 44100, 96000, 192000.\n",  samplerate );
+      break;
+
+  }
+
+}
+
+aubio_filter_t * new_aubio_filter_cdsgn (uint_t samplerate, uint_t channels) {
   aubio_filter_t * f = new_aubio_filter(samplerate, 5, channels);
-  lsmp_t * a = f->a->data[0];
-  lsmp_t * b = f->b->data[0];
-  /* uint_t l; */
-  /* for now, 44100, cdsgn */
-  a[0] =  1.000000000000000000000000000000000000000000000000000000000000; 
-  a[1] = -2.134674963687040794013682898366823792457580566406250000000000; 
-  a[2] =  1.279333533236063358273781886964570730924606323242187500000000; 
-  a[3] = -0.149559846089396208945743182994192466139793395996093750000000; 
-  a[4] =  0.004908700174624848651394604104325480875559151172637939453125; 
-  b[0] =  0.217008561949218803377448239189106971025466918945312500000000;
-  b[1] = -0.000000000000000222044604925031308084726333618164062500000000;
-  b[2] = -0.434017123898438272888711253472138196229934692382812500000000;
-  b[3] =  0.000000000000000402455846426619245903566479682922363281250000;
-  b[4] =  0.217008561949218969910901932962588034570217132568359375000000;
-  /* DBG: filter coeffs at creation time */
-  /*
-  for (l=0; l<f->order; l++){
-    AUBIO_DBG("a[%d]=\t%1.16f\tb[%d]=\t%1.16f\n",l,a[l],l,b[l]);
-  }
-  */
-  f->a->data[0] = a;
-  f->b->data[0] = b;
+  aubio_filter_set_cdsgn (f);
   return f;
 }
Index: src/temporal/cdesign.h
===================================================================
--- src/temporal/cdesign.h	(revision d9c45df5930c9964f82363e4ea88a4a9c4cda732)
+++ src/temporal/cdesign.h	(revision a4364b83d213f0c725b47bacbea5bfa39f798f91)
@@ -1,18 +1,19 @@
 /*
-   Copyright (C) 2003-2007 Paul Brossier
+  Copyright (C) 2003-2009 Paul Brossier <piem@aubio.org>
 
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2 of the License, or
-   (at your option) any later version.
+  This file is part of aubio.
 
-   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 General Public License for more details.
+  aubio is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
 
-   You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+  aubio 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 General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with aubio.  If not, see <http://www.gnu.org/licenses/>.
 
 */
@@ -23,7 +24,28 @@
 /** \file
 
-  Create a new C-design filter 
+  Create a C-weighting filter
+  
+  This file creates a C-weighting digital filter, which reduces low and high
+  frequencies and enhance the middle ones to reflect the ability of the human
+  hearing.
+  
+  The implementation is based on the following standard:
 
-  This file creates an IIR filter object with A-design coefficients.
+    - IEC/CD 1672: Electroacoustics-Sound Level Meters, IEC, Geneva, Nov.  1996,
+  for A- and C-weighting filters.
+  
+  See also:
+  
+    - <a href="http://en.wikipedia.org/wiki/A-weighting">A-Weighting on
+  Wikipedia</a>
+    - <a href="http://en.wikipedia.org/wiki/Weighting_filter">Weighting filter on
+  Wikipedia</a>
+    - <a href="http://www.mathworks.com/matlabcentral/fileexchange/69">Christophe
+  Couvreur's 'octave' toolbox</a>
+  
+  The coefficients in this file have been computed using Christophe Couvreur's
+  scripts in octave 3.0 (debian package 1:3.0.5-6+b2 with octave-signal
+  1.0.9-1+b1 on i386), with <pre> [b, a] = cdsign(1/Fs) </pre> for various
+  sampling frequencies.
 
 */
@@ -35,14 +57,19 @@
 /** create new C-design filter
 
-  \param samplerate sampling-rate of the signal to filter 
+  \param samplerate sampling frequency of the signal to filter. Should be one of 
+  8000, 16000, 22050, 44100, 96000, 192000.
   \param channels number of channels to allocate
 
+  \return a new filter object
+
 */
-aubio_filter_t * new_aubio_cdsgn_filter(uint_t samplerate, uint_t channels);
+aubio_filter_t * new_aubio_filter_cdsgn (uint_t samplerate, uint_t channels);
 
-/** filter input vector (in-place) */
-#define aubio_cdsgn_filter_do aubio_filter_do
-/** delete c-design filter object */
-#define del_aubio_cdsgn_filter del_aubio_filter
+/** set feedback and feedforward coefficients of a C-weighting filter
+
+  \param f filter object to get coefficients from
+
+*/
+void aubio_filter_set_cdsgn (aubio_filter_t *f);
 
 #ifdef __cplusplus
Index: src/temporal/filter.c
===================================================================
--- src/temporal/filter.c	(revision d9c45df5930c9964f82363e4ea88a4a9c4cda732)
+++ src/temporal/filter.c	(revision a4364b83d213f0c725b47bacbea5bfa39f798f91)
@@ -27,5 +27,13 @@
 #include "mathutils.h"
 #include "temporal/filter.h"
-#include "temporal/filter_priv.h"
+
+struct _aubio_filter_t {
+  uint_t order;
+  uint_t samplerate;
+  lvec_t * a;
+  lvec_t * b;
+  lvec_t * y;
+  lvec_t * x;
+};
 
 void aubio_filter_do(aubio_filter_t * f, fvec_t * in) {
@@ -103,5 +111,22 @@
 }
 
-aubio_filter_t * new_aubio_filter(uint_t samplerate UNUSED, uint_t order, uint_t channels) {
+lvec_t * aubio_filter_get_feedback ( aubio_filter_t *f ) {
+  return f->a;
+}
+
+lvec_t * aubio_filter_get_feedforward ( aubio_filter_t *f ) {
+  return f->b;
+}
+
+uint_t aubio_filter_get_order ( aubio_filter_t *f ) {
+  return f->order;
+}
+
+uint_t aubio_filter_get_samplerate ( aubio_filter_t *f ) {
+  return f->samplerate;
+}
+
+aubio_filter_t * new_aubio_filter(uint_t samplerate, 
+    uint_t order, uint_t channels) {
   aubio_filter_t * f = AUBIO_NEW(aubio_filter_t);
   f->x = new_lvec(order, channels);
@@ -109,14 +134,16 @@
   f->a = new_lvec(order, 1);
   f->b = new_lvec(order, 1);
+  f->samplerate = samplerate; 
+  f->order = order;
+  /* set default to identity */
   f->a->data[0][1] = 1.;
-  f->order = order;
   return f;
 }
 
 void del_aubio_filter(aubio_filter_t * f) {
-  AUBIO_FREE(f->a);
-  AUBIO_FREE(f->b);
-  AUBIO_FREE(f->x);
-  AUBIO_FREE(f->y);
+  del_lvec(f->a);
+  del_lvec(f->b);
+  del_lvec(f->x);
+  del_lvec(f->y);
   AUBIO_FREE(f);
   return;
Index: src/temporal/filter.h
===================================================================
--- src/temporal/filter.h	(revision d9c45df5930c9964f82363e4ea88a4a9c4cda732)
+++ src/temporal/filter.h	(revision a4364b83d213f0c725b47bacbea5bfa39f798f91)
@@ -23,14 +23,37 @@
 /** \file 
 
-  Infinite Impulse Response filter
+  Digital filter
 
-  This file implements IIR filters of any order:
+  This object stores a digital filter of order \f$n\f$ for \f$c\f$ channels.
+  It contains the following data:
+    - \f$ n*1 b_i \f$ feedforward coefficients 
+    - \f$ n*1 a_i \f$ feedback coefficients 
+    - \f$ n*c x_i \f$ input signal
+    - \f$ n*c y_i \f$ output signal
+
+  For convenience, the samplerate of the input signal is also stored in the object.
+
+  Feedforward and feedback parameters can be modified using
+  aubio_filter_get_feedback() and aubio_filter_get_feedforward().
+
+  The function aubio_filter_do_outplace() computes the following output signal
+  \f$ y[n] \f$ from the input signal \f$ x[n] \f$:
  
-  \f$ y[n] = b_1 x[n] + ... + b_{order} x[n-order] -
-       a_2 y[n-1] - ... - a_{order} y[n-order]\f$
+  \f{eqnarray*}{
+     y[n] = b_0 x[n] & + & b_1 x[n-1] + b_2 x[n-2] + ... + b_P x[n-P] \\
+                     & - & a_1 y[n-1] - a_2 y[n-2] - ... - a_P y[n-P] \\
+  \f}
 
-  The filtfilt version runs the filter twice, forward and backward, to
-  compensate the phase shifting of the forward operation.
+  The function aubio_filter_do() executes the same computation but modifies
+  directly the input signal (in-place).
 
+  The function aubio_filter_do_filtfilt() version runs the filter twice, first
+  forward then backward, to compensate with the phase shifting of the forward
+  operation.
+
+  Some convenience functions are provided: 
+    - new_aubio_filter_adsgn() and aubio_filter_set_adsgn(),
+    - new_aubio_filter_cdsgn() and aubio_filter_set_cdsgn().
+ 
 */
 
@@ -39,31 +62,75 @@
 #endif
 
-/** IIR filter object */
+/** Digital filter
+
+*/
 typedef struct _aubio_filter_t aubio_filter_t;
 
 /** filter input vector (in-place)
 
-  \param b biquad object as returned by new_aubio_biquad
+  \param f filter object as returned by new_aubio_filter()
   \param in input vector to filter
 
 */
-void aubio_filter_do(aubio_filter_t * b, fvec_t * in);
+void aubio_filter_do(aubio_filter_t * f, fvec_t * in);
+
 /** filter input vector (out-of-place)
 
-  \param b biquad object as returned by new_aubio_biquad
+  \param f filter object as returned by new_aubio_filter()
   \param in input vector to filter
   \param out output vector to store filtered input
 
 */
-void aubio_filter_do_outplace(aubio_filter_t * b, fvec_t * in, fvec_t * out);
+void aubio_filter_do_outplace(aubio_filter_t * f, fvec_t * in, fvec_t * out);
+
 /** filter input vector forward and backward
 
-  \param b biquad object as returned by new_aubio_biquad
-  \param in input vector to filter
+  \param f ::aubio_filter_t object as returned by new_aubio_filter()
+  \param in ::fvec_t input vector to filter
   \param tmp memory space to use for computation
 
 */
-void aubio_filter_do_filtfilt(aubio_filter_t * b, fvec_t * in, fvec_t * tmp);
-/** create new IIR filter
+void aubio_filter_do_filtfilt(aubio_filter_t * f, fvec_t * in, fvec_t * tmp);
+
+/** returns a pointer to feedback coefficients \f$ a_i \f$
+
+  \param f filter object to get parameters from
+
+  \return a pointer to the \f$ a_0 ... a_i ... a_P \f$ coefficients
+
+*/
+lvec_t * aubio_filter_get_feedback ( aubio_filter_t *f );
+
+/** returns a pointer to feedforward coefficients \f$ b_i \f$
+
+  \param f filter object to get coefficients from
+
+  \return a pointer to the \f$ b_0 ... b_i ... b_P \f$ coefficients
+
+*/
+lvec_t * aubio_filter_get_feedforward ( aubio_filter_t *f );
+
+/** get order of the filter
+
+  \param f filter to get order from
+
+  \return the order of the filter
+
+*/
+uint_t aubio_filter_get_order ( aubio_filter_t *f );
+
+/** get sampling rate of the filter
+
+  \param f filter to get sampling rate from
+
+  \return the sampling rate of the filter, in Hz
+
+*/
+uint_t aubio_filter_get_samplerate ( aubio_filter_t *f );
+
+/** create new filter object
+
+  This function creates a new ::aubio_filter_t object, given an order 
+  and a specific number of channels.
 
   \param samplerate signal sampling rate
@@ -71,6 +138,9 @@
   \param channels number of channels to allocate
 
+  \return the newly created filter object
+
 */
 aubio_filter_t * new_aubio_filter(uint_t samplerate, uint_t order, uint_t channels);
+
 /** delete a filter object
  
Index: c/temporal/filter_priv.h
===================================================================
--- src/temporal/filter_priv.h	(revision d9c45df5930c9964f82363e4ea88a4a9c4cda732)
+++ 	(revision )
@@ -1,29 +1,0 @@
-/*
-   Copyright (C) 2003-2008 Paul Brossier
-
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2 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 General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-
-*/
-
-#include "lvec.h"
-struct _aubio_filter_t {
-  uint_t order;
-  lvec_t * a;
-  lvec_t * b;
-  lvec_t * y;
-  lvec_t * x;
-};
-
-
Index: tests/src/temporal/test-aweighting.c
===================================================================
--- tests/src/temporal/test-aweighting.c	(revision a4364b83d213f0c725b47bacbea5bfa39f798f91)
+++ tests/src/temporal/test-aweighting.c	(revision a4364b83d213f0c725b47bacbea5bfa39f798f91)
@@ -0,0 +1,37 @@
+#include <aubio.h>
+
+int main(){
+  
+  aubio_filter_t * f;
+
+  uint_t rates[] = { 8000, 16000, 22050, 44100, 96000, 192000};
+  uint_t nrates = 6;
+  uint_t samplerate, i = 0;
+  uint_t channels = 2;
+
+  for ( samplerate = rates[i]; i < nrates ; i++ ) {
+    f = new_aubio_filter_adsgn (samplerate, channels);
+    del_aubio_filter (f);
+
+    f = new_aubio_filter (samplerate, 7, channels*2);
+    aubio_filter_set_adsgn (f);
+    del_aubio_filter (f);
+  }
+
+  // samplerate unknown
+  f = new_aubio_filter_adsgn (12089, channels);
+  del_aubio_filter (f);
+
+  // order to small
+  f = new_aubio_filter (samplerate, 2, channels*2);
+  aubio_filter_set_adsgn (f);
+  del_aubio_filter (f);
+
+  // order to big
+  f = new_aubio_filter (samplerate, 12, channels*2);
+  aubio_filter_set_adsgn (f);
+  del_aubio_filter (f);
+
+  return 0;
+}
+
Index: tests/src/temporal/test-cweighting.c
===================================================================
--- tests/src/temporal/test-cweighting.c	(revision a4364b83d213f0c725b47bacbea5bfa39f798f91)
+++ tests/src/temporal/test-cweighting.c	(revision a4364b83d213f0c725b47bacbea5bfa39f798f91)
@@ -0,0 +1,37 @@
+#include <aubio.h>
+
+int main(){
+  
+  aubio_filter_t * f;
+
+  uint_t rates[] = { 8000, 16000, 22050, 44100, 96000, 192000};
+  uint_t nrates = 6;
+  uint_t samplerate, i = 0;
+  uint_t channels = 2;
+
+  for ( samplerate = rates[i]; i < nrates ; i++ ) {
+    f = new_aubio_filter_cdsgn (samplerate, channels);
+    del_aubio_filter (f);
+
+    f = new_aubio_filter (samplerate, 5, channels*2);
+    aubio_filter_set_cdsgn (f);
+    del_aubio_filter (f);
+  }
+
+  // samplerate unknown
+  f = new_aubio_filter_cdsgn (12089, channels);
+  del_aubio_filter (f);
+
+  // order to small
+  f = new_aubio_filter (samplerate, 2, channels*2);
+  aubio_filter_set_cdsgn (f);
+  del_aubio_filter (f);
+
+  // order to big
+  f = new_aubio_filter (samplerate, 12, channels*2);
+  aubio_filter_set_cdsgn (f);
+  del_aubio_filter (f);
+
+  return 0;
+}
+
Index: tests/src/test-filter.c
===================================================================
--- tests/src/test-filter.c	(revision d9c45df5930c9964f82363e4ea88a4a9c4cda732)
+++ tests/src/test-filter.c	(revision a4364b83d213f0c725b47bacbea5bfa39f798f91)
@@ -9,5 +9,5 @@
   
         /* allocate fft and other memory space */
-        aubio_filter_t * o = new_aubio_cdsgn_filter(44100, channels);
+        aubio_filter_t * o = new_aubio_filter_cdsgn (44100, channels);
 
         aubio_filter_do(o,in);
