equalizer-nbands

equalizer-nbands — Direct Form IIR equalizer

Synopsis

struct              GstIirEqualizerNBands;

Object Hierarchy

  GObject
   +----GInitiallyUnowned
         +----GstObject
               +----GstElement
                     +----GstBaseTransform
                           +----GstAudioFilter
                                 +----GstIirEqualizer
                                       +----GstIirEqualizerNBands

Implemented Interfaces

GstIirEqualizerNBands implements GstChildProxy and GstPreset.

Properties

  "num-bands"                guint                 : Read / Write / Construct

Description

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

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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

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#include <gst/gst.h>

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

...

  GstElement *equalizer;
  GstObject *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));
  }

...

Synopsis

Element Information

plugin

equalizer

author

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

class

Filter/Effect/Audio

Element Pads

name

sink

direction

sink

presence

always

details

audio/x-raw, format=(string){ S16LE, F32LE, F64LE }, rate=(int)[ 1000, 2147483647 ], channels=(int)[ 1, 2147483647 ], layout=(string)interleaved

name

src

direction

source

presence

always

details

audio/x-raw, format=(string){ S16LE, F32LE, F64LE }, rate=(int)[ 1000, 2147483647 ], channels=(int)[ 1, 2147483647 ], layout=(string)interleaved

Details

struct GstIirEqualizerNBands

struct GstIirEqualizerNBands;

Property Details

The "num-bands" property

  "num-bands"                guint                 : Read / Write / Construct

number of different bands to use.

Allowed values: [1,64]

Default value: 10