audiotestsrc

audiotestsrc — Creates audio test signals of given frequency and volume

Synopsis




            GstAudioTestSrc;

Properties


  "freq"                 gdouble               : Read / Write
  "is-live"              gboolean              : Read / Write
  "samplesperbuffer"     gint                  : Read / Write
  "timestamp-offset"     gint64                : Read / Write
  "volume"               gdouble               : Read / Write
  "wave"                 GstAudioTestSrcWave   : Read / Write

Description

AudioTestSrc can be used to generate basic audio signals. It support several different waveforms and allows you to set the base frequency and volume.

Example launch line

gst-launch audiotestsrc ! audioconvert ! alsasink

This pipeline produces a sine with default frequency (mid-C) and volume.

gst-launch audiotestsrc wave=2 freq=200 ! audioconvert ! tee name=t ! alsasink t. ! libvisual_lv_scope ! ffmpegcolorspace ! xvimagesink

In this example a saw wave is generated. The wave is shown using a scope visualizer from libvisual, allowing you to visually verify that the saw wave is correct.

Element Information

plugin audiotestsrc
author Stefan Kost <ensonic@users.sf.net>
class Source/Audio

Details

GstAudioTestSrc

typedef struct {
  GstBaseSrc parent;

  void (*process)(GstAudioTestSrc*, gint16 *);

  /* parameters */
  GstAudioTestSrcWaves wave;
  gdouble volume;
  gdouble freq;
    
  /* audio parameters */
  gint samplerate;
  gint samples_per_buffer;
} GstAudioTestSrc;

Properties

The "freq" property

  "freq"                 gdouble               : Read / Write

Frequency of test signal.

Allowed values: [0,20000]

Default value: 440


The "is-live" property

  "is-live"              gboolean              : Read / Write

Whether to act as a live source.

Default value: FALSE


The "samplesperbuffer" property

  "samplesperbuffer"     gint                  : Read / Write

Number of samples in each outgoing buffer.

Allowed values: >= 1

Default value: 1024


The "timestamp-offset" property

  "timestamp-offset"     gint64                : Read / Write

An offset added to timestamps set on buffers (in ns).

Default value: 0


The "volume" property

  "volume"               gdouble               : Read / Write

Volume of test signal.

Allowed values: [0,1]

Default value: 0.8


The "wave" property

  "wave"                 GstAudioTestSrcWave   : Read / Write

Oscillator waveform.

Default value: Sine