/**

 * 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 */