audiowsincband

audiowsincband — Band pass and band reject windowed sinc filter

Synopsis

                    GstAudioWSincBand;

Object Hierarchy

  GObject
   +----GstObject
         +----GstElement
               +----GstBaseTransform
                     +----GstAudioFilter
                           +----GstAudioFXBaseFIRFilter
                                 +----GstAudioWSincBand

Properties

  "lower-frequency"          gfloat                : Read / Write
  "upper-frequency"          gfloat                : Read / Write
  "mode"                     GstAudioWSincBandMode  : Read / Write
  "window"                   GstAudioWSincBandWindow  : Read / Write
  "length"                   gint                  : Read / Write

Description

Attenuates all frequencies outside (bandpass) or inside (bandreject) of a frequency band. The length parameter controls the rolloff, the window parameter controls rolloff and stopband attenuation. The Hamming window provides a faster rolloff but a bit worse stopband attenuation, the other way around for the Blackman window.

This element has the advantage over the Chebyshev bandpass and bandreject filter that it has a much better rolloff when using a larger kernel size and almost linear phase. The only disadvantage is the much slower execution time with larger kernels.

Example launch line

gst-launch audiotestsrc freq=1500 ! audioconvert ! audiosincband mode=band-pass lower-frequency=3000 upper-frequency=10000 length=501 window=blackman ! audioconvert ! alsasink
gst-launch filesrc location="melo1.ogg" ! oggdemux ! vorbisdec ! audioconvert ! audiowsincband mode=band-reject lower-frequency=59 upper-frequency=61 length=10001 window=hamming ! audioconvert ! alsasink
gst-launch audiotestsrc wave=white-noise ! audioconvert ! audiowsincband mode=band-pass lower-frequency=1000 upper-frequency=2000 length=31 ! audioconvert ! alsasink

Details

GstAudioWSincBand

typedef struct _GstAudioWSincBand GstAudioWSincBand;

Opaque data structure.

Property Details

The `"lower-frequency"` property

  "lower-frequency"          gfloat                : Read / Write

Cut-off lower frequency (Hz).

Allowed values: [0,100000]

Default value: 0

The `"upper-frequency"` property

  "upper-frequency"          gfloat                : Read / Write

Cut-off upper frequency (Hz).

Allowed values: [0,100000]

Default value: 0

The `"mode"` property

  "mode"                     GstAudioWSincBandMode  : Read / Write

Band pass or band reject mode.

Default value: Band pass (default)

The `"window"` property

  "window"                   GstAudioWSincBandWindow  : Read / Write

Window function to use.

Default value: Hamming window (default)

The `"length"` property

  "length"                   gint                  : Read / Write

Filter kernel length, will be rounded to the next odd number.

Allowed values: [3,256000]

Default value: 101

			GStreamer Good Plugins 0.10 Plugins Reference Manual
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