/* GStreamer StreamVolume * Copyright (C) 2009 Sebastian Dröge * * 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 #include 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_AUDIO_API GType gst_stream_volume_get_type (void); GST_AUDIO_API void gst_stream_volume_set_volume (GstStreamVolume *volume, GstStreamVolumeFormat format, gdouble val); GST_AUDIO_API gdouble gst_stream_volume_get_volume (GstStreamVolume *volume, GstStreamVolumeFormat format); GST_AUDIO_API void gst_stream_volume_set_mute (GstStreamVolume *volume, gboolean mute); GST_AUDIO_API gboolean gst_stream_volume_get_mute (GstStreamVolume *volume); GST_AUDIO_API gdouble gst_stream_volume_convert_volume (GstStreamVolumeFormat from, GstStreamVolumeFormat to, gdouble val) G_GNUC_CONST; G_END_DECLS #endif /* __GST_STREAM_VOLUME_H__ */