equalizer-nbands

The n-band equalizer element is a fully parametric equalizer. It allows to select between 1 and 64 bands and has properties on each band to change the center frequency, band width and gain.

Example launch line

 gst-launch-1.0 filesrc location=song.ogg ! oggdemux ! vorbisdec ! audioconvert ! equalizer-nbands num-bands=15 band5::gain=6.0 ! alsasink

This make the equalizer use 15 bands and raises the volume of the 5th band by 6 db.

Example code

 #include <gst/gst.h>

 ...
 typedef struct {
   gfloat freq;
   gfloat width;
   gfloat gain;
 } GstEqualizerBandState;

 ...

   GstElement *equalizer;
   GObject *band;
   gint i;
   GstEqualizerBandState state[] = {
     { 120.0,   50.0, - 3.0},
     { 500.0,   20.0,  12.0},
     {1503.0,    2.0, -20.0},
     {6000.0, 1000.0,   6.0},
     {3000.0,  120.0,   2.0}
   };

 ...

   equalizer = gst_element_factory_make ("equalizer-nbands", "equalizer");
   g_object_set (G_OBJECT (equalizer), "num-bands", 5, NULL);

 ...

   for (i = 0; i < 5; i++) {
     band = gst_child_proxy_get_child_by_index (GST_CHILD_PROXY (equalizer), i);
     g_object_set (G_OBJECT (band), "freq", state[i].freq,
         "bandwidth", state[i].width,
 	"gain", state[i].gain);
     g_object_unref (G_OBJECT (band));
   }

 ...