audiotestsrc: GStreamer Base Plugins 1.0 Plugins Reference Manual

## audiotestsrc audiotestsrc |

## Properties

gboolean | can-activate-pull | Read / Write
gboolean | can-activate-push | Read / Write
gdouble | freq | Read / Write
gboolean | is-live | Read / Write
gint | samplesperbuffer | Read / Write
gint64 | timestamp-offset | Read / Write
gdouble | volume | Read / Write
GstAudioTestSrcWave | wave | Read / Write

## Types and Values

struct | GstAudioTestSrc
enum | GstAudioTestSrcWave

## Object Hierarchy

        GObject
        ╰── GInitiallyUnowned
            ╰── GstObject
                ╰── GstElement
                    ╰── GstBaseSrc
                        ╰── GstAudioTestSrc

## Description

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

Waveform specific notes:

1. Gaussian white noise

2. Ticks

#### Example launch line

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    gst-launch-1.0 audiotestsrc ! audioconvert ! autoaudiosink

This pipeline produces a sine with default frequency, 440 Hz, and the default volume, 0.8 (relative to a maximum 1.0).

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    2
    gst-launch-1.0 audiotestsrc wave=2 freq=200 ! tee name=t ! queue ! audioconvert ! \
        autoaudiosink t. ! queue ! audioconvert ! libvisual_lv_scope ! videoconvert ! autovideosink

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.

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    gst-launch-1.0 audiotestsrc wave=ticks apply-tick-ramp=true tick-interval=100000000 \
        freq=10000 volume=0.4 marker-tick-period=10 sine-periods-per-tick=20 ! autoaudiosink

This pipeline produces a series of 10 kHz sine wave ticks. Each tick is 20 sine wave periods long, ticks occur every 100 ms and have a volume of 0.4. Every 10th tick is a marker tick and has the default marker tick volume of 1.0. The beginning and end of the ticks are modulated with the ramp.

## 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, S16BE, U16LE, U16BE, S24_32LE, S24_32BE, U24_32LE, U24_32BE, S32LE, S32BE, U32LE, U32BE, S24LE, S24BE, U24LE, U24BE, S20LE, S20BE, U20LE, U20BE, S18LE, S18BE, U18LE, U18BE, F32LE, F32BE, F64LE, F64BE, S8, U8 }, layout=(string)interleaved, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ]

## Functions

## Types and Values

### struct GstAudioTestSrc

    struct GstAudioTestSrc;

audiotestsrc object structure.

### enum GstAudioTestSrcWave

Different types of supported sound waves.

#### Members

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 |
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 `“can-activate-pull”` property

      “can-activate-pull”        gboolean

Can activate in pull mode.

Flags: Read / Write

Default value: FALSE

### The `“can-activate-push”` property

      “can-activate-push”        gboolean

Can activate in push mode.

Flags: Read / Write

Default value: TRUE

### The `“freq”` property

      “freq”                     gdouble

Frequency of test signal. The sample rate needs to be at least 4 times higher.

Flags: Read / Write

Allowed values: [0,5.36871e+08]

Default value: 440

### The `“is-live”` property

      “is-live”                  gboolean

Whether to act as a live source.

Flags: Read / Write

Default value: FALSE

### The `“samplesperbuffer”` property

      “samplesperbuffer”         gint

Number of samples in each outgoing buffer.

Flags: Read / Write

Allowed values: >= 1

Default value: 1024

### The `“timestamp-offset”` property

      “timestamp-offset”         gint64

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

Flags: Read / Write

Default value: 0

### The `“volume”` property

      “volume”                   gdouble

Volume of test signal.

Flags: Read / Write

Allowed values: [0,1]

Default value: 0.8

### The `“wave”` property

      “wave”                     GstAudioTestSrcWave

Oscillator waveform.

Flags: Read / Write

Default value: Sine