GstStreamVolume: GStreamer Base Plugins 1.0 Library Reference Manual

GstStreamVolume

GstStreamVolume — Interface for elements that provide a stream volume

Functions

gdouble	gst_stream_volume_get_volume ()
void	gst_stream_volume_set_volume ()
gboolean	gst_stream_volume_get_mute ()
void	gst_stream_volume_set_mute ()
gdouble	gst_stream_volume_convert_volume ()

Properties

gboolean	mute	Read / Write
gdouble	volume	Read / Write

Types and Values

	GstStreamVolume
enum	GstStreamVolumeFormat

Object Hierarchy

    GInterface
    ╰── GstStreamVolume

Prerequisites

GstStreamVolume requires GObject.

Includes

#include <gst/audio/streamvolume.h>

Description

This interface is implemented by elements that provide a stream volume. Examples for such elements are volume and playbin.

Applications can use this interface to get or set the current stream volume. For this the "volume" GObject property can be used or the helper functions gst_stream_volume_set_volume() and gst_stream_volume_get_volume(). This volume is always a linear factor, i.e. 0.0 is muted 1.0 is 100%. For showing the volume in a GUI it might make sense to convert it to a different format by using gst_stream_volume_convert_volume(). Volume sliders should usually use a cubic volume.

Separate from the volume the stream can also be muted by the "mute" GObject property or gst_stream_volume_set_mute() and gst_stream_volume_get_mute().

Elements that provide some kind of stream volume should implement the "volume" and "mute" GObject properties and handle setting and getting of them properly. The volume property is defined to be a linear volume factor.

Functions

gst_stream_volume_get_volume ()

gdouble
gst_stream_volume_get_volume (GstStreamVolume *volume,
                              GstStreamVolumeFormat format);

Parameters

volume	GstStreamVolume that should be used
format	GstStreamVolumeFormat which should be returned

Returns

The current stream volume as linear factor

gst_stream_volume_set_volume ()

void
gst_stream_volume_set_volume (GstStreamVolume *volume,
                              GstStreamVolumeFormat format,
                              gdouble val);

Parameters

volume	GstStreamVolume that should be used
format	GstStreamVolumeFormat of `val`
val	Linear volume factor that should be set

gst_stream_volume_get_mute ()

gboolean
gst_stream_volume_get_mute (GstStreamVolume *volume);

Parameters

volume

GstStreamVolume that should be used

Returns

Returns TRUE if the stream is muted

gst_stream_volume_set_mute ()

void
gst_stream_volume_set_mute (GstStreamVolume *volume,
                            gboolean mute);

Parameters

volume	GstStreamVolume that should be used
mute	Mute state that should be set

gst_stream_volume_convert_volume ()

gdouble
gst_stream_volume_convert_volume (GstStreamVolumeFormat from,
                                  GstStreamVolumeFormat to,
                                  gdouble val);

Parameters

from	GstStreamVolumeFormat to convert from
to	GstStreamVolumeFormat to convert to
val	Volume in `from` format that should be converted

Returns

the converted volume

Types and Values