/**

 * FreeRDP: A Remote Desktop Protocol Implementation

 * RemoteFX Codec Library - Bit Stream

 *

 * Copyright 2011 Vic Lee

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#ifndef FREERDP_LIB_CODEC_RFX_BITSTREAM_H

#define FREERDP_LIB_CODEC_RFX_BITSTREAM_H

#include <freerdp/codec/rfx.h>

struct _RFX_BITSTREAM

{

	BYTE* buffer;

	int nbytes;

	int byte_pos;

	int bits_left;

};

typedef struct _RFX_BITSTREAM RFX_BITSTREAM;

#define rfx_bitstream_attach(bs, _buffer, _nbytes) \

	do                                             \

	{                                              \

		bs->buffer = (BYTE*)(_buffer);             \

		bs->nbytes = (_nbytes);                    \

		bs->byte_pos = 0;                          \

		bs->bits_left = 8;                         \

	} while (0)

#define rfx_bitstream_get_bits(bs, _nbits, _r)                                       \

	do                                                                               \

	{                                                                                \

		int nbits = _nbits;                                                          \

		int b;                                                                       \

		UINT16 n = 0;                                                                \

		while (bs->byte_pos < bs->nbytes && nbits > 0)                               \

		{                                                                            \

			b = nbits;                                                               \

			if (b > bs->bits_left)                                                   \

				b = bs->bits_left;                                                   \

			if (n)                                                                   \

				n <<= b;                                                             \

			n |= (bs->buffer[bs->byte_pos] >> (bs->bits_left - b)) & ((1 << b) - 1); \

			bs->bits_left -= b;                                                      \

			nbits -= b;                                                              \

			if (bs->bits_left == 0)                                                  \

			{                                                                        \

				bs->bits_left = 8;                                                   \

				bs->byte_pos++;                                                      \

			}                                                                        \

		}                                                                            \

		_r = n;                                                                      \

	} while (0)

#define rfx_bitstream_put_bits(bs, _bits, _nbits)                                \

	do                                                                           \

	{                                                                            \

		UINT16 bits = (_bits);                                                   \

		int nbits = (_nbits);                                                    \

		int b;                                                                   \

		while (bs->byte_pos < bs->nbytes && nbits > 0)                           \

		{                                                                        \

			b = nbits;                                                           \

			if (b > bs->bits_left)                                               \

				b = bs->bits_left;                                               \

			bs->buffer[bs->byte_pos] |= ((bits >> (nbits - b)) & ((1 << b) - 1)) \

			                            << (bs->bits_left - b);                  \

			bs->bits_left -= b;                                                  \

			nbits -= b;                                                          \

			if (bs->bits_left == 0)                                              \

			{                                                                    \

				bs->bits_left = 8;                                               \

				bs->byte_pos++;                                                  \

			}                                                                    \

		}                                                                        \

	} while (0)

#define rfx_bitstream_flush(bs)                    \

	do                                             \

	{                                              \

		if (bs->bits_left != 8)                    \

		{                                          \

			int _nbits = 8 - bs->bits_left;        \

			rfx_bitstream_put_bits(bs, 0, _nbits); \

		}                                          \

	} while (0)

#define rfx_bitstream_eos(_bs) ((_bs)->byte_pos >= (_bs)->nbytes)

#define rfx_bitstream_left(_bs)       \

	((_bs)->byte_pos >= (_bs)->nbytes \

	     ? 0                          \

	     : ((_bs)->nbytes - (_bs)->byte_pos - 1) * 8 + (_bs)->bits_left)

#define rfx_bitstream_get_processed_bytes(_bs) \

	((_bs)->bits_left < 8 ? (_bs)->byte_pos + 1 : (_bs)->byte_pos)

#endif /* FREERDP_LIB_CODEC_RFX_BITSTREAM_H */