gstreamer/gst-libs/gst/audio/streamvolume.h

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/* GStreamer StreamVolume
* Copyright (C) 2009 Sebastian Dröge <sebastian.droege@collabora.co.uk>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef __GST_STREAM_VOLUME_H__
#define __GST_STREAM_VOLUME_H__
#include <gst/gst.h>
G_BEGIN_DECLS
#define GST_TYPE_STREAM_VOLUME \
(gst_stream_volume_get_type ())
#define GST_STREAM_VOLUME(obj) \
(G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_STREAM_VOLUME, GstStreamVolume))
#define GST_IS_STREAM_VOLUME(obj) \
(G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_STREAM_VOLUME))
#define GST_STREAM_VOLUME_GET_INTERFACE(inst) \
(G_TYPE_INSTANCE_GET_INTERFACE ((inst), GST_TYPE_STREAM_VOLUME, GstStreamVolumeInterface))
typedef struct _GstStreamVolume GstStreamVolume;
typedef struct _GstStreamVolumeInterface GstStreamVolumeInterface;
struct _GstStreamVolumeInterface {
GTypeInterface iface;
};
/**
* GstStreamVolumeFormat:
* @GST_STREAM_VOLUME_FORMAT_LINEAR: Linear scale factor, 1.0 = 100%
* @GST_STREAM_VOLUME_FORMAT_CUBIC: Cubic volume scale
* @GST_STREAM_VOLUME_FORMAT_DB: Logarithmic volume scale (dB, amplitude not power)
*
* Different representations of a stream volume. gst_stream_volume_convert_volume()
* allows to convert between the different representations.
*
* Formulas to convert from a linear to a cubic or dB volume are
* cbrt(val) and 20 * log10 (val).
*/
typedef enum {
GST_STREAM_VOLUME_FORMAT_LINEAR = 0,
GST_STREAM_VOLUME_FORMAT_CUBIC,
GST_STREAM_VOLUME_FORMAT_DB
} GstStreamVolumeFormat;
GST_EXPORT
GType gst_stream_volume_get_type (void);
GST_EXPORT
void gst_stream_volume_set_volume (GstStreamVolume *volume,
GstStreamVolumeFormat format,
gdouble val);
GST_EXPORT
gdouble gst_stream_volume_get_volume (GstStreamVolume *volume,
GstStreamVolumeFormat format);
GST_EXPORT
void gst_stream_volume_set_mute (GstStreamVolume *volume,
gboolean mute);
GST_EXPORT
gboolean gst_stream_volume_get_mute (GstStreamVolume *volume);
GST_EXPORT
gdouble gst_stream_volume_convert_volume (GstStreamVolumeFormat from,
GstStreamVolumeFormat to,
gdouble val) G_GNUC_CONST;
G_END_DECLS
#endif /* __GST_STREAM_VOLUME_H__ */