audiotestsrc

audiotestsrc — Creates audio test signals of given frequency and volume

Synopsis

struct              GstAudioTestSrc;
enum                GstAudioTestSrcWave;

Object Hierarchy

  GObject
   +----GInitiallyUnowned
         +----GstObject
               +----GstElement
                     +----GstBaseSrc
                           +----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
  "can-activate-pull"        gboolean              : Read / Write
  "can-activate-push"        gboolean              : Read / Write

Description

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

Example launch line

1
gst-launch audiotestsrc ! audioconvert ! alsasink
This pipeline produces a sine with default frequency, 440 Hz, and the default volume, 0.8 (relative to a maximum 1.0).
1
gst-launch audiotestsrc wave=2 freq=200 ! audioconvert ! tee name=t ! queue ! alsasink t. ! queue ! libvisual_lv_scope ! videoconvert ! 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.

Synopsis

Element Information

plugin

audiotestsrc

author

Stefan Kost <ensonic@users.sf.net>

class

Source/Audio

Element Pads

name

src

direction

source

presence

always

details

audio/x-raw, format=(string){ S16LE, S32LE, F32LE, F64LE }, layout=(string)interleaved, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2 ]

Details

struct GstAudioTestSrc

struct GstAudioTestSrc;

audiotestsrc object structure.


enum GstAudioTestSrcWave

typedef enum {
  GST_AUDIO_TEST_SRC_WAVE_SINE,
  GST_AUDIO_TEST_SRC_WAVE_SQUARE,
  GST_AUDIO_TEST_SRC_WAVE_SAW,
  GST_AUDIO_TEST_SRC_WAVE_TRIANGLE,
  GST_AUDIO_TEST_SRC_WAVE_SILENCE,
  GST_AUDIO_TEST_SRC_WAVE_WHITE_NOISE,
  GST_AUDIO_TEST_SRC_WAVE_PINK_NOISE,
  GST_AUDIO_TEST_SRC_WAVE_SINE_TAB,
  GST_AUDIO_TEST_SRC_WAVE_TICKS,
  GST_AUDIO_TEST_SRC_WAVE_GAUSSIAN_WHITE_NOISE,
  GST_AUDIO_TEST_SRC_WAVE_RED_NOISE,
  GST_AUDIO_TEST_SRC_WAVE_BLUE_NOISE,
  GST_AUDIO_TEST_SRC_WAVE_VIOLET_NOISE
} GstAudioTestSrcWave;

Different types of supported sound waves.

GST_AUDIO_TEST_SRC_WAVE_SINE

a sine wave

GST_AUDIO_TEST_SRC_WAVE_SQUARE

a square wave

GST_AUDIO_TEST_SRC_WAVE_SAW

a saw wave

GST_AUDIO_TEST_SRC_WAVE_TRIANGLE

a tringle wave

GST_AUDIO_TEST_SRC_WAVE_SILENCE

silence

GST_AUDIO_TEST_SRC_WAVE_WHITE_NOISE

white uniform noise

GST_AUDIO_TEST_SRC_WAVE_PINK_NOISE

pink noise

GST_AUDIO_TEST_SRC_WAVE_SINE_TAB

sine wave using a table

GST_AUDIO_TEST_SRC_WAVE_TICKS

periodic ticks

GST_AUDIO_TEST_SRC_WAVE_GAUSSIAN_WHITE_NOISE

white (zero mean) Gaussian noise; volume sets the standard deviation of the noise in units of the range of values of the sample type, e.g. volume=0.1 produces noise with a standard deviation of 0.1*32767=3277 with 16-bit integer samples, or 0.1*1.0=0.1 with floating-point samples.

GST_AUDIO_TEST_SRC_WAVE_RED_NOISE

red (brownian) noise

GST_AUDIO_TEST_SRC_WAVE_BLUE_NOISE

spectraly inverted pink noise

GST_AUDIO_TEST_SRC_WAVE_VIOLET_NOISE

spectraly inverted red (brownian) noise

Property Details

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


The "can-activate-pull" property

  "can-activate-pull"        gboolean              : Read / Write

Can activate in pull mode.

Default value: FALSE


The "can-activate-push" property

  "can-activate-push"        gboolean              : Read / Write

Can activate in push mode.

Default value: TRUE