moved struct AudioFormat to audio_format.h

We want to expose the AudioFormat structure to plugins; remove some
clutter by moving its declaration to a separate header file.

src/audio_format.h

@@ -0,0 +1,35 @@
+/* the Music Player Daemon (MPD)
+ * Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com)
+ * This project's homepage is: http://www.musicpd.org
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef AUDIO_FORMAT_H
+#define AUDIO_FORMAT_H
+
+#include "mpd_types.h"
+
+typedef struct _AudioFormat {
+	volatile mpd_sint8 channels;
+	volatile mpd_uint32 sampleRate;
+	volatile mpd_sint8 bits;
+} AudioFormat;
+
+static inline double audioFormatSizeToTime(const AudioFormat * af)
+{
+	return 8.0 / af->bits / af->channels / af->sampleRate;
+}
+
+#endif