# 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));
       }

     ...

## Hierarchy

    GObject
        ╰──GInitiallyUnowned
            ╰──GstObject
                ╰──GstElement
                    ╰──GstBaseTransform
                        ╰──GstAudioFilter
                            ╰──GstIirEqualizer
                                ╰──equalizer-nbands

## Implemented interfaces

    GstChildProxy
    GstPreset

## Factory details

Authors: – Benjamin Otte <otte@gnome.org>, Stefan Kost <ensonic@users.sf.net></ensonic@users.sf.net></otte@gnome.org>

Classification: – `Filter/Effect/Audio`

Rank – none

Plugin – equalizer

Package – GStreamer Good Plug-ins

## Pad Templates

### `sink`

    audio/x-raw:
             format: { S16LE, F32LE, F64LE }
               rate: [ 1000, 2147483647 ]
           channels: [ 1, 2147483647 ]
             layout: interleaved

Presence – always

Direction – sink

Object type – GstPad

### `src`

    audio/x-raw:
             format: { S16LE, F32LE, F64LE }
               rate: [ 1000, 2147483647 ]
           channels: [ 1, 2147483647 ]
             layout: interleaved

Presence – always

Direction – src

Object type – GstPad

## Properties

### num-bands

    “num-bands” guint

number of different bands to use

Flags : Read / Write / Construct

Default value : 10

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