IMAGE: Beginning of Indeo 4 decoder, added GetBits class for reading bits

1 files changed, 169 insertions, 0 deletions

diff --git a/image/codecs/indeo/get_bits.h b/image/codecs/indeo/get_bits.h
new file mode 100644
index 0000000000..dd6ba55dd2
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+++ b/image/codecs/indeo/get_bits.h
@@ -0,0 +1,169 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * 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.
+ *
+ */
+
+#include "common/scummsys.h"
+
+/* Intel Indeo 4 bitstream reader
+ *
+ * Original copyright note:
+ * Copyright (c) 2004 Michael Niedermayer
+ */
+
+#ifndef IMAGE_CODECS_INDEO_GET_BITS_H
+#define IMAGE_CODECS_INDEO_GET_BITS_H
+
+#include "common/scummsys.h"
+
+namespace Image {
+namespace Indeo {
+
+#define AV_INPUT_BUFFER_PADDING_SIZE 32
+
+/**
+ * Intel Indeo Bitstream reader
+ */
+class GetBits {
+private:
+	const byte *_buffer;
+	uint _index;
+	uint _sizeInBits;
+	uint _sizeInBitsPlus8;
+public:
+	/**
+	* Constructor
+	* @param buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes
+	*        larger than the actual read bits because some optimized bitstream
+	*        readers read 32 or 64 bit at once and could read over the end
+	* @param bit_size the size of the buffer in bits
+	* @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.
+	*/
+	GetBits(const byte *buffer, size_t totalBits);
+	
+	GetBits(const GetBits &src);
+	
+	/**
+	 * Returns the number of bits read
+	 */
+	uint getBitsCount() const { return _index; }
+
+	/**
+	 * The number of bits left
+	 */
+	int getBitsLeft() const { return _sizeInBits - _index; }
+
+	void skipBitsLong(uint n) { _index += n; }
+
+	/**
+	 * Read MPEG-1 dc-style VLC (sign bit + mantissa with no MSB).
+	 * if MSB not set it is negative
+	 * @param n length in bits
+	 */
+	int getXbits(int n);
+
+	/**
+	 * Returns the next n bits, and does sign extension
+	 */
+	int getSbits(int n);
+
+	/**
+	 * Read 1-25 bits.
+	 */
+	uint getBits(int n);
+
+	/**
+	 * Read 0-25 bits.
+	 */
+	int getBitsZ(int n);
+
+	uint getBitsLE(int n);
+
+	/**
+	 * Show 1-25 bits.
+	 * Returns the data without updating the index
+	 */
+	uint showBits(int n);
+
+	/**
+	 * Skips a specified number of bits
+	 */
+	void skipBits(int n);
+
+	/**
+	 * Returns the next bit
+	 */
+	uint getBits1();
+
+	/**
+	 * Shows the next following bit
+	 */
+	uint showBits1();
+
+	/**
+	 * Skips the next bit
+	 */
+	void skipBits1();
+
+	/**
+	 * Read 0-32 bits.
+	 */
+	uint getBitsLong(int n);
+
+	/**
+	 * Read 0-64 bits.
+	 */
+	uint64 getBits64(int n);
+
+	/**
+	 * Read 0-32 bits as a signed integer.
+	 */
+	int getSbitsLong(int n);
+
+	/**
+	 * Show 0-32 bits.
+	 */
+	uint showBitsLong(int n);
+
+	int checkMarker(void *logctx, const char *msg);
+
+	/**
+	 * Parse a VLC code.
+	 * @param bits is the number of bits which will be read at once, must be
+	 *             identical to nb_bits in init_vlc()
+	 * @param max_depth is the number of times bits bits must be read to completely
+	 *                  read the longest vlc code
+	 *                  = (max_vlc_length + bits - 1) / bits
+	 */
+	int getVLC2(int(*table)[2], int bits, int maxDepth);
+
+	int decode012();
+
+	int decode210();
+
+	int skip1stop8dataBits();
+
+	const byte *alignGetBits();
+};
+
+} // End of namespace Indeo
+} // End of namespace Image
+
+#endif