fixed volume control

1 files changed, 57 insertions, 0 deletions

diff --git a/volume.c b/volume.c
new file mode 100644
index 00000000..85a9a125
--- /dev/null
+++ b/volume.c
@@ -0,0 +1,57 @@
+/*
+    DeaDBeeF - ultimate music player for GNU/Linux systems with X11
+    Copyright (C) 2009  Alexey Yakovenko
+
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    as published by the Free Software Foundation; either version 2
+    of the License, or (at your option) any later version.
+    
+    This program 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 General Public License for more details.
+    
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+#include <math.h>
+#include <stdio.h>
+#include "volume.h"
+
+static float volume_db = 0; // in dB
+static float volume_amp = 1; // amplitude [0..1]
+
+void
+volume_set_db (float dB) {
+    volume_db = dB;
+    volume_amp = dB > -60 ? db_to_amp (dB) : 0;
+}
+
+float
+volume_get_db (void) {
+    return volume_db;
+}
+
+void
+volume_set_amp (float amp) {
+    volume_amp = amp;
+    volume_db = amp > 0 ? amp_to_db (amp) : -60.f;
+}
+
+float
+volume_get_amp (void) {
+    return volume_amp;
+}
+
+float
+db_to_amp (float dB) {
+    return pow (10, dB/20.f);
+}
+
+float
+amp_to_db (float amp) {
+    return 20*log10 (amp);
+}
+