139 lines
3.2 KiB
C
139 lines
3.2 KiB
C
/**
|
|
* 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 <winpr/assert.h>
|
|
#include <winpr/cast.h>
|
|
|
|
#include <freerdp/codec/rfx.h>
|
|
|
|
#ifdef __cplusplus
|
|
extern "C"
|
|
{
|
|
#endif
|
|
|
|
typedef struct
|
|
{
|
|
BYTE* buffer;
|
|
uint32_t nbytes;
|
|
uint32_t byte_pos;
|
|
uint32_t bits_left;
|
|
} RFX_BITSTREAM;
|
|
|
|
static inline void rfx_bitstream_attach(RFX_BITSTREAM* bs, BYTE* WINPR_RESTRICT buffer,
|
|
size_t nbytes)
|
|
{
|
|
WINPR_ASSERT(bs);
|
|
bs->buffer = (buffer);
|
|
|
|
WINPR_ASSERT(nbytes <= UINT32_MAX);
|
|
bs->nbytes = WINPR_ASSERTING_INT_CAST(uint32_t, nbytes);
|
|
bs->byte_pos = 0;
|
|
bs->bits_left = 8;
|
|
}
|
|
|
|
WINPR_ATTR_NODISCARD
|
|
static inline uint32_t rfx_bitstream_get_bits(RFX_BITSTREAM* bs, uint32_t nbits)
|
|
{
|
|
UINT16 n = 0;
|
|
while (bs->byte_pos < bs->nbytes && nbits > 0)
|
|
{
|
|
uint32_t 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++;
|
|
}
|
|
}
|
|
return n;
|
|
}
|
|
|
|
static inline void rfx_bitstream_put_bits(RFX_BITSTREAM* bs, uint32_t _bits, uint32_t _nbits)
|
|
{
|
|
UINT16 bits = WINPR_ASSERTING_INT_CAST(UINT16, _bits);
|
|
|
|
uint32_t nbits = (_nbits);
|
|
while (bs->byte_pos < bs->nbytes && nbits > 0)
|
|
{
|
|
uint32_t 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++;
|
|
}
|
|
}
|
|
}
|
|
|
|
static inline void rfx_bitstream_flush(RFX_BITSTREAM* bs)
|
|
{
|
|
WINPR_ASSERT(bs);
|
|
if (bs->bits_left != 8)
|
|
{
|
|
uint32_t _nbits = 8 - bs->bits_left;
|
|
rfx_bitstream_put_bits(bs, 0, _nbits);
|
|
}
|
|
}
|
|
|
|
WINPR_ATTR_NODISCARD
|
|
static inline BOOL rfx_bitstream_eos(RFX_BITSTREAM* bs)
|
|
{
|
|
WINPR_ASSERT(bs);
|
|
return ((bs)->byte_pos >= (bs)->nbytes);
|
|
}
|
|
|
|
WINPR_ATTR_NODISCARD
|
|
static inline uint32_t rfx_bitstream_left(RFX_BITSTREAM* bs)
|
|
{
|
|
WINPR_ASSERT(bs);
|
|
|
|
if ((bs)->byte_pos >= (bs)->nbytes)
|
|
return 0;
|
|
|
|
return ((bs)->nbytes - (bs)->byte_pos - 1) * 8 + (bs)->bits_left;
|
|
}
|
|
|
|
WINPR_ATTR_NODISCARD
|
|
static inline uint32_t rfx_bitstream_get_processed_bytes(RFX_BITSTREAM* bs)
|
|
{
|
|
WINPR_ASSERT(bs);
|
|
if ((bs)->bits_left < 8)
|
|
return (bs)->byte_pos + 1;
|
|
return (bs)->byte_pos;
|
|
}
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
#endif /* FREERDP_LIB_CODEC_RFX_BITSTREAM_H */
|