1 files changed, 192 insertions, 0 deletions
diff --git a/src/decoder/flac_metadata.c b/src/decoder/flac_metadata.c
new file mode 100644
index 000000000..912559c8d
--- /dev/null
+++ b/src/decoder/flac_metadata.c
@@ -0,0 +1,192 @@
+/*
+ * 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 "flac_metadata.h"
+#include "replay_gain.h"
+#include "tag.h"
+
+#include <glib.h>
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+static bool
+flac_find_float_comment(const FLAC__StreamMetadata *block,
+			const char *cmnt, float *fl)
+{
+	int offset;
+	size_t pos;
+	int len;
+	unsigned char tmp, *p;
+
+	offset = FLAC__metadata_object_vorbiscomment_find_entry_from(block, 0,
+								     cmnt);
+	if (offset < 0)
+		return false;
+
+	pos = strlen(cmnt) + 1; /* 1 is for '=' */
+	len = block->data.vorbis_comment.comments[offset].length - pos;
+	if (len <= 0)
+		return false;
+
+	p = &block->data.vorbis_comment.comments[offset].entry[pos];
+	tmp = p[len];
+	p[len] = '\0';
+	*fl = (float)atof((char *)p);
+	p[len] = tmp;
+
+	return true;
+}
+
+struct replay_gain_info *
+flac_parse_replay_gain(const FLAC__StreamMetadata *block)
+{
+	struct replay_gain_info *rgi;
+	bool found = false;
+
+	rgi = replay_gain_info_new();
+
+	found = flac_find_float_comment(block, "replaygain_album_gain",
+					&rgi->tuples[REPLAY_GAIN_ALBUM].gain) ||
+		flac_find_float_comment(block, "replaygain_album_peak",
+					&rgi->tuples[REPLAY_GAIN_ALBUM].peak) ||
+		flac_find_float_comment(block, "replaygain_track_gain",
+					&rgi->tuples[REPLAY_GAIN_TRACK].gain) ||
+		flac_find_float_comment(block, "replaygain_track_peak",
+					&rgi->tuples[REPLAY_GAIN_TRACK].peak);
+	if (!found) {
+		replay_gain_info_free(rgi);
+		rgi = NULL;
+	}
+
+	return rgi;
+}
+
+/**
+ * Checks if the specified name matches the entry's name, and if yes,
+ * returns the comment value (not null-temrinated).
+ */
+static const char *
+flac_comment_value(const FLAC__StreamMetadata_VorbisComment_Entry *entry,
+		   const char *name, const char *char_tnum, size_t *length_r)
+{
+	size_t name_length = strlen(name);
+	size_t char_tnum_length = 0;
+	const char *comment = (const char*)entry->entry;
+
+	if (entry->length <= name_length ||
+	    g_ascii_strncasecmp(comment, name, name_length) != 0)
+		return NULL;
+
+	if (char_tnum != NULL) {
+		char_tnum_length = strlen(char_tnum);
+		if (entry->length > name_length + char_tnum_length + 2 &&
+		    comment[name_length] == '[' &&
+		    g_ascii_strncasecmp(comment + name_length + 1,
+					char_tnum, char_tnum_length) == 0 &&
+		    comment[name_length + char_tnum_length + 1] == ']')
+			name_length = name_length + char_tnum_length + 2;
+		else if (entry->length > name_length + char_tnum_length &&
+			 g_ascii_strncasecmp(comment + name_length,
+					     char_tnum, char_tnum_length) == 0)
+			name_length = name_length + char_tnum_length;
+	}
+
+	if (comment[name_length] == '=') {
+		*length_r = entry->length - name_length - 1;
+		return comment + name_length + 1;
+	}
+
+	return NULL;
+}
+
+/**
+ * Check if the comment's name equals the passed name, and if so, copy
+ * the comment value into the tag.
+ */
+static bool
+flac_copy_comment(struct tag *tag,
+		  const FLAC__StreamMetadata_VorbisComment_Entry *entry,
+		  const char *name, enum tag_type tag_type,
+		  const char *char_tnum)
+{
+	const char *value;
+	size_t value_length;
+
+	value = flac_comment_value(entry, name, char_tnum, &value_length);
+	if (value != NULL) {
+		tag_add_item_n(tag, tag_type, value, value_length);
+		return true;
+	}
+
+	return false;
+}
+
+/* tracknumber is used in VCs, MPD uses "track" ..., all the other
+ * tag names match */
+static const char *VORBIS_COMMENT_TRACK_KEY = "tracknumber";
+static const char *VORBIS_COMMENT_DISC_KEY = "discnumber";
+
+static void
+flac_parse_comment(struct tag *tag, const char *char_tnum,
+		   const FLAC__StreamMetadata_VorbisComment_Entry *entry)
+{
+	assert(tag != NULL);
+
+	if (flac_copy_comment(tag, entry, VORBIS_COMMENT_TRACK_KEY,
+			      TAG_TRACK, char_tnum) ||
+	    flac_copy_comment(tag, entry, VORBIS_COMMENT_DISC_KEY,
+			      TAG_DISC, char_tnum) ||
+	    flac_copy_comment(tag, entry, "album artist",
+			      TAG_ALBUM_ARTIST, char_tnum))
+		return;
+
+	for (unsigned i = 0; i < TAG_NUM_OF_ITEM_TYPES; ++i)
+		if (flac_copy_comment(tag, entry,
+				      tag_item_names[i], i, char_tnum))
+			return;
+}
+
+void
+flac_vorbis_comments_to_tag(struct tag *tag, const char *char_tnum,
+			    const FLAC__StreamMetadata_VorbisComment *comment)
+{
+	for (unsigned i = 0; i < comment->num_comments; ++i)
+		flac_parse_comment(tag, char_tnum, &comment->comments[i]);
+}
+
+void
+flac_tag_apply_metadata(struct tag *tag, const char *track,
+			const FLAC__StreamMetadata *block)
+{
+	switch (block->type) {
+	case FLAC__METADATA_TYPE_VORBIS_COMMENT:
+		flac_vorbis_comments_to_tag(tag, track,
+					    &block->data.vorbis_comment);
+		break;
+
+	case FLAC__METADATA_TYPE_STREAMINFO:
+		tag->time = flac_duration(&block->data.stream_info);
+		break;
+
+	default:
+		break;
+	}
+}