1 /* GStreamer StreamVolume 2 * Copyright (C) 2009 Sebastian Dröge <sebastian.droege@collabora.co.uk> 3 * 4 * This library is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Library General Public 6 * License as published by the Free Software Foundation; either 7 * version 2 of the License, or (at your option) any later version. 8 * 9 * This library is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Library General Public License for more details. 13 * 14 * You should have received a copy of the GNU Library General Public 15 * License along with this library; if not, write to the 16 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, 17 * Boston, MA 02110-1301, USA. 18 */ 19 20 #ifndef __GST_STREAM_VOLUME_H__ 21 #define __GST_STREAM_VOLUME_H__ 22 23 #include <gst/gst.h> 24 #include <gst/audio/audio-prelude.h> 25 26 G_BEGIN_DECLS 27 28 #define GST_TYPE_STREAM_VOLUME \ 29 (gst_stream_volume_get_type ()) 30 #define GST_STREAM_VOLUME(obj) \ 31 (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_STREAM_VOLUME, GstStreamVolume)) 32 #define GST_IS_STREAM_VOLUME(obj) \ 33 (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_STREAM_VOLUME)) 34 #define GST_STREAM_VOLUME_GET_INTERFACE(inst) \ 35 (G_TYPE_INSTANCE_GET_INTERFACE ((inst), GST_TYPE_STREAM_VOLUME, GstStreamVolumeInterface)) 36 37 typedef struct _GstStreamVolume GstStreamVolume; 38 typedef struct _GstStreamVolumeInterface GstStreamVolumeInterface; 39 40 struct _GstStreamVolumeInterface { 41 GTypeInterface iface; 42 }; 43 44 /** 45 * GstStreamVolumeFormat: 46 * @GST_STREAM_VOLUME_FORMAT_LINEAR: Linear scale factor, 1.0 = 100% 47 * @GST_STREAM_VOLUME_FORMAT_CUBIC: Cubic volume scale 48 * @GST_STREAM_VOLUME_FORMAT_DB: Logarithmic volume scale (dB, amplitude not power) 49 * 50 * Different representations of a stream volume. gst_stream_volume_convert_volume() 51 * allows to convert between the different representations. 52 * 53 * Formulas to convert from a linear to a cubic or dB volume are 54 * cbrt(val) and 20 * log10 (val). 55 */ 56 typedef enum { 57 GST_STREAM_VOLUME_FORMAT_LINEAR = 0, 58 GST_STREAM_VOLUME_FORMAT_CUBIC, 59 GST_STREAM_VOLUME_FORMAT_DB 60 } GstStreamVolumeFormat; 61 62 GST_AUDIO_API 63 GType gst_stream_volume_get_type (void); 64 65 GST_AUDIO_API 66 void gst_stream_volume_set_volume (GstStreamVolume *volume, 67 GstStreamVolumeFormat format, 68 gdouble val); 69 70 GST_AUDIO_API 71 gdouble gst_stream_volume_get_volume (GstStreamVolume *volume, 72 GstStreamVolumeFormat format); 73 74 GST_AUDIO_API 75 void gst_stream_volume_set_mute (GstStreamVolume *volume, 76 gboolean mute); 77 78 GST_AUDIO_API 79 gboolean gst_stream_volume_get_mute (GstStreamVolume *volume); 80 81 GST_AUDIO_API 82 gdouble gst_stream_volume_convert_volume (GstStreamVolumeFormat from, 83 GstStreamVolumeFormat to, 84 gdouble val) G_GNUC_CONST; 85 86 G_END_DECLS 87 88 #endif /* __GST_STREAM_VOLUME_H__ */ 89