audio_format: added function audio_format_to_string()

Unified function for converting an audio_format object to a string,
for log messages and for the "status" command.

src/audio_format.c

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2003-2009 The Music Player Daemon Project
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "audio_format.h"
+
+#include <assert.h>
+#include <stdio.h>
+
+#if G_BYTE_ORDER == G_BIG_ENDIAN
+#define REVERSE_ENDIAN_SUFFIX "_le"
+#else
+#define REVERSE_ENDIAN_SUFFIX "_be"
+#endif
+
+const char *
+audio_format_to_string(const struct audio_format *af,
+		       struct audio_format_string *s)
+{
+	assert(af != NULL);
+	assert(s != NULL);
+
+	snprintf(s->buffer, sizeof(s->buffer), "%u:%u%s:%u",
+		 af->sample_rate, af->bits,
+		 af->reverse_endian ? REVERSE_ENDIAN_SUFFIX : "",
+		 af->channels);
+
+	return s->buffer;
+}