playlist/embcue: new plugin for reading embedded cue sheets

Parses CUE data from the "CUESHEET" tag.  Needs further integration in
the update thread.

2 files changed, 193 insertions, 0 deletions

diff --git a/src/playlist/embcue_playlist_plugin.c b/src/playlist/embcue_playlist_plugin.c
new file mode 100644
index 00000000..b05b98e4
--- /dev/null
+++ b/src/playlist/embcue_playlist_plugin.c
@@ -0,0 +1,168 @@
+/*
+ * 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.
+ */
+
+/** \file
+ *
+ * Playlist plugin that reads embedded cue sheets from the "CUESHEET"
+ * tag of a music file.
+ */
+
+#include "config.h"
+#include "playlist/embcue_playlist_plugin.h"
+#include "playlist_plugin.h"
+#include "tag.h"
+#include "tag_handler.h"
+#include "tag_file.h"
+#include "tag_ape.h"
+#include "tag_id3.h"
+#include "song.h"
+#include "cue/cue_parser.h"
+
+#include <glib.h>
+#include <assert.h>
+#include <string.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "cue"
+
+struct embcue_playlist {
+	struct playlist_provider base;
+
+	/**
+	 * The value of the file's "CUESHEET" tag.
+	 */
+	char *cuesheet;
+
+	/**
+	 * The offset of the next line within "cuesheet".
+	 */
+	char *next;
+
+	struct cue_parser *parser;
+};
+
+static void
+embcue_tag_pair(const char *name, const char *value, void *ctx)
+{
+	struct embcue_playlist *playlist = ctx;
+
+	if (playlist->cuesheet == NULL &&
+	    g_ascii_strcasecmp(name, "cuesheet") == 0)
+		playlist->cuesheet = g_strdup(value);
+}
+
+static const struct tag_handler embcue_tag_handler = {
+	.pair = embcue_tag_pair,
+};
+
+static struct playlist_provider *
+embcue_playlist_open_uri(const char *uri,
+			 G_GNUC_UNUSED GMutex *mutex,
+			 G_GNUC_UNUSED GCond *cond)
+{
+	if (!g_path_is_absolute(uri))
+		/* only local files supported */
+		return NULL;
+
+	struct embcue_playlist *playlist = g_new(struct embcue_playlist, 1);
+	playlist_provider_init(&playlist->base, &embcue_playlist_plugin);
+	playlist->cuesheet = NULL;
+
+	tag_file_scan(uri, &embcue_tag_handler, playlist);
+	if (playlist->cuesheet == NULL) {
+		tag_ape_scan2(uri, &embcue_tag_handler, playlist);
+		if (playlist->cuesheet == NULL)
+			tag_id3_scan(uri, &embcue_tag_handler, playlist);
+	}
+
+	if (playlist->cuesheet == NULL) {
+		/* no "CUESHEET" tag found */
+		g_free(playlist);
+		return NULL;
+	}
+
+	playlist->next = playlist->cuesheet;
+	playlist->parser = cue_parser_new();
+
+	return &playlist->base;
+}
+
+static void
+embcue_playlist_close(struct playlist_provider *_playlist)
+{
+	struct embcue_playlist *playlist = (struct embcue_playlist *)_playlist;
+
+	cue_parser_free(playlist->parser);
+	g_free(playlist->cuesheet);
+	g_free(playlist);
+}
+
+static struct song *
+embcue_playlist_read(struct playlist_provider *_playlist)
+{
+	struct embcue_playlist *playlist = (struct embcue_playlist *)_playlist;
+
+	struct song *song = cue_parser_get(playlist->parser);
+	if (song != NULL)
+		return song;
+
+	while (*playlist->next != 0) {
+		const char *line = playlist->next;
+		char *eol = strpbrk(playlist->next, "\r\n");
+		if (eol != NULL) {
+			/* null-terminate the line */
+			*eol = 0;
+			playlist->next = eol + 1;
+		} else
+			/* last line; put the "next" pointer to the
+			   end of the buffer */
+			playlist->next += strlen(line);
+
+		cue_parser_feed(playlist->parser, line);
+		song = cue_parser_get(playlist->parser);
+		if (song != NULL)
+			return song;
+	}
+
+	cue_parser_finish(playlist->parser);
+	return cue_parser_get(playlist->parser);
+}
+
+static const char *const embcue_playlist_suffixes[] = {
+	/* a few codecs that are known to be supported; there are
+	   probably many more */
+	"flac",
+	"mp3", "mp2",
+	"mp4", "mp4a", "m4b",
+	"ape",
+	"wv",
+	"ogg", "oga",
+	NULL
+};
+
+const struct playlist_plugin embcue_playlist_plugin = {
+	.name = "cue",
+
+	.open_uri = embcue_playlist_open_uri,
+	.close = embcue_playlist_close,
+	.read = embcue_playlist_read,
+
+	.suffixes = embcue_playlist_suffixes,
+	.mime_types = NULL,
+};
diff --git a/src/playlist/embcue_playlist_plugin.h b/src/playlist/embcue_playlist_plugin.h
new file mode 100644
index 00000000..c5f21b27
--- /dev/null
+++ b/src/playlist/embcue_playlist_plugin.h
@@ -0,0 +1,25 @@
+/*
+ * 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.
+ */
+
+#ifndef MPD_PLAYLIST_EMBCUE_PLAYLIST_PLUGIN_H
+#define MPD_PLAYLIST_EMBCUE_PLAYLIST_PLUGIN_H
+
+extern const struct playlist_plugin embcue_playlist_plugin;
+
+#endif