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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 |
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.
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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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.
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 ] |
Types and Values
enum GstAudioTestSrcWave
Different types of supported sound waves.
Members
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a sine wave |
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a square wave |
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a saw wave |
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a tringle wave |
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silence |
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white uniform noise |
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pink noise |
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sine wave using a table |
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periodic ticks |
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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. |
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red (brownian) noise |
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spectraly inverted pink noise |
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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