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-rw-r--r--src/riff.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/src/riff.c b/src/riff.c
new file mode 100644
index 000000000..9af0a2127
--- /dev/null
+++ b/src/riff.c
@@ -0,0 +1,104 @@
+/*
+ * 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
+ */
+
+#include "riff.h"
+
+#include <glib.h>
+
+#include <stdint.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "riff"
+
+struct riff_header {
+ char id[4];
+ uint32_t size;
+ char format[4];
+};
+
+struct riff_chunk_header {
+ char id[4];
+ uint32_t size;
+};
+
+size_t
+riff_seek_id3(FILE *file)
+{
+ int ret;
+ struct stat st;
+ struct riff_header header;
+ struct riff_chunk_header chunk;
+ size_t size;
+
+ /* determine the file size */
+
+ ret = fstat(fileno(file), &st);
+ if (ret < 0) {
+ g_warning("Failed to stat file descriptor: %s",
+ strerror(errno));
+ return 0;
+ }
+
+ /* seek to the beginning and read the RIFF header */
+
+ ret = fseek(file, 0, SEEK_SET);
+ if (ret != 0) {
+ g_warning("Failed to seek: %s", g_strerror(errno));
+ return 0;
+ }
+
+ size = fread(&header, sizeof(header), 1, file);
+ if (size != 1 ||
+ memcmp(header.id, "RIFF", 4) != 0 ||
+ GUINT32_FROM_LE(header.size) > st.st_size)
+ /* not a RIFF file */
+ return 0;
+
+ while (true) {
+ /* read the chunk header */
+
+ size = fread(&chunk, sizeof(chunk), 1, file);
+ if (size != 1)
+ return 0;
+
+ size = GUINT32_FROM_LE(chunk.size);
+ if (size % 2 != 0)
+ /* pad byte */
+ ++size;
+
+ g_debug("chunk='%.4s' size=%zu\n", chunk.id, size);
+
+ if (memcmp(chunk.id, "id3 ", 4) == 0)
+ /* found it! */
+ return size;
+
+ if ((off_t)size < 0)
+ /* integer underflow after cast to signed
+ type */
+ return 0;
+
+ ret = fseek(file, size, SEEK_CUR);
+ if (ret != 0)
+ return 0;
+ }
+}