decoder/{dsf,dsdiff}: convert to C++

src/decoder/DsdLib.cxx

@@ -0,0 +1,171 @@
+/*
+ * Copyright (C) 2003-2013 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 "decoder_api.h"
+#include "util/bit_reverse.h"
+#include "tag_handler.h"
+
+extern "C" {
+#include "tag_id3.h"
+}
+
+#include <unistd.h>
+#include <stdio.h> /* for SEEK_SET, SEEK_CUR */
+
+#ifdef HAVE_ID3TAG
+#include <id3tag.h>
+#endif
+
+bool
+dsdlib_id_equals(const struct dsdlib_id *id, const char *s)
+{
+	assert(id != nullptr);
+	assert(s != nullptr);
+	assert(strlen(s) == sizeof(id->value));
+
+	return memcmp(id->value, s, sizeof(id->value)) == 0;
+}
+
+bool
+dsdlib_read(struct decoder *decoder, struct input_stream *is,
+	    void *data, size_t length)
+{
+	size_t nbytes = decoder_read(decoder, is, data, length);
+	return nbytes == length;
+}
+
+/**
+ * Skip the #input_stream to the specified offset.
+ */
+bool
+dsdlib_skip_to(struct decoder *decoder, struct input_stream *is,
+	       goffset offset)
+{
+	if (input_stream_is_seekable(is))
+		return input_stream_seek(is, offset, SEEK_SET, nullptr);
+
+	if (input_stream_get_offset(is) > offset)
+		return false;
+
+	char buffer[8192];
+	while (input_stream_get_offset(is) < offset) {
+		size_t length = sizeof(buffer);
+		if (offset - input_stream_get_offset(is) < (goffset)length)
+			length = offset - input_stream_get_offset(is);
+
+		size_t nbytes = decoder_read(decoder, is, buffer, length);
+		if (nbytes == 0)
+			return false;
+	}
+
+	assert(input_stream_get_offset(is) == offset);
+	return true;
+}
+
+/**
+ * Skip some bytes from the #input_stream.
+ */
+bool
+dsdlib_skip(struct decoder *decoder, struct input_stream *is,
+	    goffset delta)
+{
+	assert(delta >= 0);
+
+	if (delta == 0)
+		return true;
+
+	if (input_stream_is_seekable(is))
+		return input_stream_seek(is, delta, SEEK_CUR, nullptr);
+
+	char buffer[8192];
+	while (delta > 0) {
+		size_t length = sizeof(buffer);
+		if ((goffset)length > delta)
+			length = delta;
+
+		size_t nbytes = decoder_read(decoder, is, buffer, length);
+		if (nbytes == 0)
+			return false;
+
+		delta -= nbytes;
+	}
+
+	return true;
+}
+
+/**
+ * Add tags from ID3 tag. All tags commonly found in the ID3 tags of
+ * DSF and DSDIFF files are imported
+ */
+
+#ifdef HAVE_ID3TAG
+void
+dsdlib_tag_id3(struct input_stream *is,
+	       const struct tag_handler *handler,
+	       void *handler_ctx, goffset 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 goffset size = input_stream_get_size(is);
+	const goffset offset = input_stream_get_offset(is);
+	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 (!dsdlib_read(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