1 files changed, 131 insertions, 0 deletions
diff --git a/src/decoder/plugins/DsdLib.cxx b/src/decoder/plugins/DsdLib.cxx
new file mode 100644
index 000000000..0f10b20e9
--- /dev/null
+++ b/src/decoder/plugins/DsdLib.cxx
@@ -0,0 +1,131 @@
+/*
+ * Copyright (C) 2003-2014 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
+ *
+ * This file contains functions used by the DSF and DSDIFF decoders.
+ *
+ */
+
+#include "config.h"
+#include "DsdLib.hxx"
+#include "../DecoderAPI.hxx"
+#include "input/InputStream.hxx"
+#include "tag/TagId3.hxx"
+#include "util/Error.hxx"
+
+#include <string.h>
+
+#ifdef HAVE_ID3TAG
+#include <id3tag.h>
+#endif
+
+bool
+DsdId::Equals(const char *s) const
+{
+	assert(s != nullptr);
+	assert(strlen(s) == sizeof(value));
+
+	return memcmp(value, s, sizeof(value)) == 0;
+}
+
+/**
+ * Skip the #input_stream to the specified offset.
+ */
+bool
+dsdlib_skip_to(Decoder *decoder, InputStream &is,
+	       uint64_t offset)
+{
+	if (is.IsSeekable())
+		return is.Seek(offset, IgnoreError());
+
+	if (uint64_t(is.GetOffset()) > offset)
+		return false;
+
+	return dsdlib_skip(decoder, is, offset - is.GetOffset());
+}
+
+/**
+ * Skip some bytes from the #input_stream.
+ */
+bool
+dsdlib_skip(Decoder *decoder, InputStream &is,
+	    uint64_t delta)
+{
+	if (delta == 0)
+		return true;
+
+	if (is.IsSeekable())
+		return is.Seek(is.GetOffset() + delta, IgnoreError());
+
+	if (delta > 1024 * 1024)
+		/* don't skip more than one megabyte; it would be too
+		   expensive */
+		return false;
+
+	return decoder_skip(decoder, is, delta);
+}
+
+#ifdef HAVE_ID3TAG
+void
+dsdlib_tag_id3(InputStream &is,
+	       const struct tag_handler *handler,
+	       void *handler_ctx, int64_t tagoffset)
+{
+	assert(tagoffset >= 0);
+
+	if (tagoffset == 0)
+		return;
+
+	if (!dsdlib_skip_to(nullptr, is, tagoffset))
+		return;
+
+	struct id3_tag *id3_tag = nullptr;
+	id3_length_t count;
+
+	/* Prevent broken files causing problems */
+	const auto size = is.GetSize();
+	const auto offset = is.GetOffset();
+	if (offset >= size)
+		return;
+
+	count = size - offset;
+
+	/* Check and limit id3 tag size to prevent a stack overflow */
+	if (count == 0 || count > 4096)
+		return;
+
+	id3_byte_t dsdid3[count];
+	id3_byte_t *dsdid3data;
+	dsdid3data = dsdid3;
+
+	if (!decoder_read_full(nullptr, is, dsdid3data, count))
+		return;
+
+	id3_tag = id3_tag_parse(dsdid3data, count);
+	if (id3_tag == nullptr)
+		return;
+
+	scan_id3_tag(id3_tag, handler, handler_ctx);
+
+	id3_tag_delete(id3_tag);
+
+	return;
+}
+#endif