shithub: aubio

Info  •  Files  •  Log  •  Branches

onsetdection.{c,h}: add spectral flux (L2 norm, only energy increases)

--- a/src/onsetdetection.c

+++ b/src/onsetdetection.c

@@ -195,6 +195,19 @@

   }

 }

+/* Spectral flux */

+void aubio_onsetdetection_specflux(aubio_onsetdetection_t *o, cvec_t * fftgrain, fvec_t * onset){ 

+  uint_t i, j;

+  for (i=0;i<fftgrain->channels;i++) {

+    onset->data[i][0] = 0.;

+    for (j=0;j<fftgrain->length;j++) {

+      if (fftgrain->norm[i][j] > o->oldmag->data[i][j])

+        onset->data[i][0] += fftgrain->norm[i][j] - o->oldmag->data[i][j];

+      o->oldmag->data[i][j] = fftgrain->norm[i][j];

+    }

+  }

+}

+

 /* Generic function pointing to the choosen one */

 void 

 aubio_onsetdetection(aubio_onsetdetection_t *o, cvec_t * fftgrain, 

@@ -242,6 +255,7 @@

       break;

     case aubio_onset_kl:

     case aubio_onset_mkl:

+    case aubio_onset_specflux:

       o->oldmag = new_fvec(rsize,channels);

       break;

     default:

@@ -273,6 +287,9 @@

       break;

     case aubio_onset_mkl:

       o->funcpointer = aubio_onsetdetection_mkl;

+      break;

+    case aubio_onset_specflux:

+      o->funcpointer = aubio_onsetdetection_specflux;

       break;

     default:

       break;

--- a/src/onsetdetection.h

+++ b/src/onsetdetection.h

@@ -47,6 +47,7 @@

         aubio_onset_phase,          /**< phase fast */            

         aubio_onset_kl,             /**< Kullback Liebler */

         aubio_onset_mkl,            /**< modified Kullback Liebler */

+        aubio_onset_specflux,       /**< spectral flux */

 } aubio_onsetdetection_type;

 /** onsetdetection structure */

@@ -136,6 +137,18 @@

 */

 void aubio_onsetdetection_mkl(aubio_onsetdetection_t *o, cvec_t * fftgrain, fvec_t * onset);

+/** Spectral Flux 

+

+  Simon Dixon, Onset Detection Revisited, in ``Proceedings of the 9th

+  International Conference on Digital Audio Effects'' (DAFx-06), Montreal,

+  Canada, 2006. 

+

+  \param o onset detection object as returned by new_aubio_onsetdetection()

+  \param fftgrain input spectral frame

+  \param onset output onset detection function

+

+*/

+void aubio_onsetdetection_specflux(aubio_onsetdetection_t *o, cvec_t * fftgrain, fvec_t * onset);

 /** execute onset detection function on a spectral frame 

   Generic function to compute onset detection.