1 files changed, 131 insertions, 0 deletions
diff --git a/src/decoder/vorbis_comments.c b/src/decoder/vorbis_comments.c
new file mode 100644
index 000000000..98b5166e5
--- /dev/null
+++ b/src/decoder/vorbis_comments.c
@@ -0,0 +1,131 @@
+/*
+ * Copyright (C) 2003-2012 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 "config.h"
+#include "vorbis_comments.h"
+#include "tag.h"
+#include "replay_gain_info.h"
+
+#include <glib.h>
+#include <assert.h>
+#include <stddef.h>
+#include <string.h>
+#include <stdlib.h>
+
+static const char *
+vorbis_comment_value(const char *comment, const char *needle)
+{
+	size_t len = strlen(needle);
+
+	if (g_ascii_strncasecmp(comment, needle, len) == 0 &&
+	    comment[len] == '=')
+		return comment + len + 1;
+
+	return NULL;
+}
+
+bool
+vorbis_comments_to_replay_gain(struct replay_gain_info *rgi, char **comments)
+{
+	const char *temp;
+	bool found = false;
+
+	replay_gain_info_init(rgi);
+
+	while (*comments) {
+		if ((temp =
+		     vorbis_comment_value(*comments, "replaygain_track_gain"))) {
+			rgi->tuples[REPLAY_GAIN_TRACK].gain = atof(temp);
+			found = true;
+		} else if ((temp = vorbis_comment_value(*comments,
+							"replaygain_album_gain"))) {
+			rgi->tuples[REPLAY_GAIN_ALBUM].gain = atof(temp);
+			found = true;
+		} else if ((temp = vorbis_comment_value(*comments,
+							"replaygain_track_peak"))) {
+			rgi->tuples[REPLAY_GAIN_TRACK].peak = atof(temp);
+			found = true;
+		} else if ((temp = vorbis_comment_value(*comments,
+							"replaygain_album_peak"))) {
+			rgi->tuples[REPLAY_GAIN_ALBUM].peak = atof(temp);
+			found = true;
+		}
+
+		comments++;
+	}
+
+	return found;
+}
+
+static const char *VORBIS_COMMENT_TRACK_KEY = "tracknumber";
+static const char *VORBIS_COMMENT_DISC_KEY = "discnumber";
+
+/**
+ * Check if the comment's name equals the passed name, and if so, copy
+ * the comment value into the tag.
+ */
+static bool
+vorbis_copy_comment(struct tag *tag, const char *comment,
+		    const char *name, enum tag_type tag_type)
+{
+	const char *value;
+
+	value = vorbis_comment_value(comment, name);
+	if (value != NULL) {
+		tag_add_item(tag, tag_type, value);
+		return true;
+	}
+
+	return false;
+}
+
+static void
+vorbis_parse_comment(struct tag *tag, const char *comment)
+{
+	assert(tag != NULL);
+
+	if (vorbis_copy_comment(tag, comment, VORBIS_COMMENT_TRACK_KEY,
+				TAG_TRACK) ||
+	    vorbis_copy_comment(tag, comment, VORBIS_COMMENT_DISC_KEY,
+				TAG_DISC) ||
+	    vorbis_copy_comment(tag, comment, "album artist",
+				TAG_ALBUM_ARTIST))
+		return;
+
+	for (unsigned i = 0; i < TAG_NUM_OF_ITEM_TYPES; ++i)
+		if (vorbis_copy_comment(tag, comment,
+					tag_item_names[i], i))
+			return;
+}
+
+struct tag *
+vorbis_comments_to_tag(char **comments)
+{
+	struct tag *tag = tag_new();
+
+	while (*comments)
+		vorbis_parse_comment(tag, *comments++);
+
+	if (tag_is_empty(tag)) {
+		tag_free(tag);
+		tag = NULL;
+	}
+
+	return tag;
+}