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src/temporal/filter.c: reset filter memory in filtfilt

--- a/src/temporal/filter.c

+++ b/src/temporal/filter.c

@@ -79,35 +79,19 @@

   }

 }

-/*  

- *

- * despite mirroring, end effects destroy both phse and amplitude. the longer

- * the buffer, the less affected they are.

- *

- * replacing with zeros clicks.

- *

- * seems broken for order > 4 (see biquad_do_filtfilt for audible one) 

- */

+/* The rough way: reset memory of filter between each run to avoid end effects. */

 void aubio_filter_do_filtfilt(aubio_filter_t * f, fvec_t * in, fvec_t * tmp) {

   uint_t j,i=0;

   uint_t length = in->length;

-  //uint_t order = f->order;

-  //lsmp_t mir;

-  /* mirroring */

-  //mir = 2*in->data[i][0];

-  //for (j=1;j<order;j++)

-  //f->x[j] = 0.;//mir - in->data[i][order-j];

   /* apply filtering */

   aubio_filter_do(f,in);

-  /* invert */

+  aubio_filter_do_reset(f);

+  /* mirror */

   for (j = 0; j < length; j++)

     tmp->data[i][length-j-1] = in->data[i][j];

-  /* mirror inverted */

-  //mir = 2*tmp->data[i][0];

-  //for (j=1;j<order;j++)

-  //f->x[j] = 0.;//mir - tmp->data[i][order-j];

-  /* apply filtering on inverted */

+  /* apply filtering on mirrored */

   aubio_filter_do(f,tmp);

+  aubio_filter_do_reset(f);

   /* invert back */

   for (j = 0; j < length; j++)

     in->data[i][j] = tmp->data[i][length-j-1];

@@ -142,6 +126,13 @@

 {

   f->samplerate = samplerate;

   return AUBIO_OK;

+}

+

+void

+aubio_filter_do_reset (aubio_filter_t * f)

+{

+  lvec_zeros(f->x);

+  lvec_zeros(f->y);

 }

 aubio_filter_t *

--- a/src/temporal/filter.h

+++ b/src/temporal/filter.h

@@ -140,6 +140,9 @@

 */

 uint_t aubio_filter_set_samplerate (aubio_filter_t * f, uint_t samplerate);

+/** reset filter memory */

+void aubio_filter_do_reset (aubio_filter_t * f);

+

 /** create new filter object

   This function creates a new ::aubio_filter_t object, given an order