1 files changed, 97 insertions, 0 deletions
diff --git a/src/decoder/OpusReader.hxx b/src/decoder/OpusReader.hxx
new file mode 100644
index 000000000..2cfc14118
--- /dev/null
+++ b/src/decoder/OpusReader.hxx
@@ -0,0 +1,97 @@
+/*
+ * 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_OPUS_READER_HXX
+#define MPD_OPUS_READER_HXX
+
+#include "check.h"
+
+#include <stdint.h>
+#include <string.h>
+
+class OpusReader {
+	const uint8_t *p, *const end;
+
+public:
+	OpusReader(const void *_p, size_t size)
+		:p((const uint8_t *)_p), end(p + size) {}
+
+	bool Skip(size_t length) {
+		p += length;
+		return p <= end;
+	}
+
+	const void *Read(size_t length) {
+		const uint8_t *result = p;
+		return Skip(length)
+			? result
+			: nullptr;
+	}
+
+	bool Expect(const void *value, size_t length) {
+		const void *data = Read(length);
+		return data != nullptr && memcmp(value, data, length) == 0;
+	}
+
+	bool ReadByte(uint8_t &value_r) {
+		if (p >= end)
+			return false;
+
+		value_r = *p++;
+		return true;
+	}
+
+	bool ReadShort(uint16_t &value_r) {
+		const uint8_t *value = (const uint8_t *)Read(sizeof(value_r));
+		if (value == nullptr)
+			return false;
+
+		value_r = value[0] | (value[1] << 8);
+		return true;
+	}
+
+	bool ReadWord(uint32_t &value_r) {
+		const uint8_t *value = (const uint8_t *)Read(sizeof(value_r));
+		if (value == nullptr)
+			return false;
+
+		value_r = value[0] | (value[1] << 8)
+			| (value[2] << 16) | (value[3] << 24);
+		return true;
+	}
+
+	bool SkipString() {
+		uint32_t length;
+		return ReadWord(length) && Skip(length);
+	}
+
+	char *ReadString() {
+		uint32_t length;
+		if (!ReadWord(length))
+			return nullptr;
+
+		const char *src = (const char *)Read(length);
+		if (src == nullptr)
+			return nullptr;
+
+		return strndup(src, length);
+	}
+};
+
+#endif