add interpolation to yin

add interpolation to yin

diff --git a/src/mathutils.c b/src/mathutils.c
index df2a471a1552b941c30046c018c941d218803ef6..da5fe927755e9a2237963a08cd3c0fa01614e694 100644 (file)
--- a/src/mathutils.c
+++ b/src/mathutils.c
@@ -330,6 +330,28 @@ smpl_t vec_quadint(fvec_t * x,uint_t pos) {
   return exactpos;
 }
 
+smpl_t vec_quadint_min(fvec_t * x,uint_t pos, uint_t span) {
+  smpl_t step = 1./200.;
+  /* init resold to - something (in case x[pos+-span]<0)) */
+  smpl_t res, frac, s0, s1, s2, exactpos = (smpl_t)pos, resold = 100000.;
+  if ((pos > span) && (pos < x->length-span)) {
+    s0 = x->data[0][pos-span];
+    s1 = x->data[0][pos]     ;
+    s2 = x->data[0][pos+span];
+    /* increase frac */
+    for (frac = 0.; frac < 2.; frac = frac + step) {
+      res = aubio_quadfrac(s0, s1, s2, frac);
+      if (res < resold) {
+        resold = res;
+      } else {                         
+        exactpos += (frac-step)*span - span/2.;
+        break;
+      }
+    }
+  }
+  return exactpos;
+}
+
 smpl_t aubio_quadfrac(smpl_t s0, smpl_t s1, smpl_t s2, smpl_t pf) {
   smpl_t tmp = s0 + (pf/2.) * (pf * ( s0 - 2.*s1 + s2 ) - 3.*s0 + 4.*s1 - s2);
   return tmp;

diff --git a/src/mathutils.h b/src/mathutils.h
index e4499ff33f85e13a5c5d4500ed370924af0c1596..a66780dd5da2d8a7d4471f32e3ceb8b34dbde5e3 100644 (file)
--- a/src/mathutils.h
+++ b/src/mathutils.h
@@ -211,9 +211,12 @@ smpl_t vec_moving_thres(fvec_t * vec, fvec_t * tmp,
  */
 smpl_t vec_median(fvec_t * input);
 
-/** finds exact peak position by quadratic interpolation*/
+/** finds exact maximum position by quadratic interpolation*/
 smpl_t vec_quadint(fvec_t * x,uint_t pos);
 
+/** finds exact minimum position by quadratic interpolation*/
+smpl_t vec_quadint_min(fvec_t * x,uint_t pos, uint_t span);
+
 /** Quadratic interpolation using Lagrange polynomial.
  *
  * inspired from ``Comparison of interpolation algorithms in real-time sound

diff --git a/src/pitchyin.c b/src/pitchyin.c
index efd6db993289ad6c98b8fd06a64c524fac5ef5d3..76505f2980eb1d64853e2294ae68365f05a9d44c 100644 (file)
--- a/src/pitchyin.c
+++ b/src/pitchyin.c
@@ -88,8 +88,9 @@ uint_t aubio_pitchyin_getpitch(fvec_t * yin) {
 
 
 /* all the above in one */
-uint_t aubio_pitchyin_getpitchfast(fvec_t * input, fvec_t * yin, smpl_t tol){
+smpl_t aubio_pitchyin_getpitchfast(fvec_t * input, fvec_t * yin, smpl_t tol){
        uint_t c=0,j,tau = 0;
+       sint_t period;
        smpl_t tmp = 0., tmp2 = 0.;
        yin->data[c][0] = 1.;
        for (tau=1;tau<yin->length;tau++)
@@ -102,9 +103,10 @@ uint_t aubio_pitchyin_getpitchfast(fvec_t * input, fvec_t * yin, smpl_t tol){
                }
                tmp2 += yin->data[c][tau];
                yin->data[c][tau] *= tau/tmp2;
-               if((yin->data[c][tau] < tol) && 
-                                (yin->data[c][tau-1] < yin->data[c][tau])) {
-                       return tau-1;
+               period = tau-3;
+               if(tau > 4 && (yin->data[c][period] < tol) && 
+                                (yin->data[c][period] < yin->data[c][period+1])) {
+                       return vec_quadint_min(yin,period,1)-1;
                }
         }
        return 0;

diff --git a/src/pitchyin.h b/src/pitchyin.h
index b50de01a7e9785f635efdaf5bf19b2c14cdbd4ec..b21c0bfe3a1b6bba02538f6452ff63f403890397 100644 (file)
--- a/src/pitchyin.h
+++ b/src/pitchyin.h
@@ -38,7 +38,7 @@ void aubio_pitchyin_getcum(fvec_t * yinbuf);
 
 uint_t aubio_pitchyin_getpitch(fvec_t *yinbuf);
 
-uint_t aubio_pitchyin_getpitchfast(fvec_t * input, fvec_t *yinbuf, smpl_t tol);
+smpl_t aubio_pitchyin_getpitchfast(fvec_t * input, fvec_t *yinbuf, smpl_t tol);
 
 #ifdef __cplusplus
 }