audio: replaced parseAudioConfig() with audio_format_parse()

Added audio_format_parse() in a separate library, with a modern
interface: return a GError instead of logging errors.  This allows the
caller to deal with the error.

src/audio_parser.c

@@ -0,0 +1,98 @@
+/*
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/*
+ * Parser functions for audio related objects.
+ *
+ */
+
+#include "audio_parser.h"
+#include "audio_format.h"
+
+#include <stdlib.h>
+
+/**
+ * The GLib quark used for errors reported by this library.
+ */
+static inline GQuark
+audio_parser_quark(void)
+{
+	return g_quark_from_static_string("audio_parser");
+}
+
+bool
+audio_format_parse(struct audio_format *dest, const char *src, GError **error)
+{
+	char *endptr;
+	unsigned long value;
+
+	audio_format_clear(dest);
+
+	/* parse sample rate */
+
+	value = strtoul(src, &endptr, 10);
+	if (endptr == src) {
+		g_set_error(error, audio_parser_quark(), 0,
+			    "Sample rate missing");
+		return false;
+	} else if (*endptr != ':') {
+		g_set_error(error, audio_parser_quark(), 0,
+			    "Sample format missing");
+		return false;
+	} else if (value <= 0 || value > G_MAXINT32) {
+		g_set_error(error, audio_parser_quark(), 0,
+			    "Invalid sample rate: %lu", value);
+		return false;
+	}
+
+	dest->sample_rate = value;
+
+	/* parse sample format */
+
+	src = endptr + 1;
+	value = strtoul(src, &endptr, 10);
+	if (endptr == src) {
+		g_set_error(error, audio_parser_quark(), 0,
+			    "Sample format missing");
+		return false;
+	} else if (*endptr != ':') {
+		g_set_error(error, audio_parser_quark(), 0,
+			    "Channel count missing");
+		return false;
+	} else if (value != 16 && value != 24 && value != 8) {
+		g_set_error(error, audio_parser_quark(), 0,
+			    "Invalid sample format: %lu", value);
+		return false;
+	}
+
+	dest->bits = value;
+
+	/* parse channel count */
+
+	src = endptr + 1;
+	value = strtoul(src, &endptr, 10);
+	if (*endptr != 0 || (value != 1 && value != 2)) {
+		g_set_error(error, audio_parser_quark(), 0,
+			    "Invalid channel count: %s", src);
+		return false;
+	}
+
+	dest->channels = value;
+
+	return true;
+}