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/*
* WinPR: Windows Portable Runtime
* BitStream Utils
*
* Copyright 2014 Marc-Andre Moreau <marcandre.moreau@gmail.com>
*
* 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 WINPR_UTILS_BITSTREAM_H
#define WINPR_UTILS_BITSTREAM_H
#include <winpr/assert.h>
#include <winpr/winpr.h>
#include <winpr/wtypes.h>
#include <winpr/crt.h>
#include <winpr/wlog.h>
typedef struct
{
const BYTE* buffer;
BYTE* pointer;
UINT32 position;
UINT32 length;
UINT32 capacity;
UINT32 mask;
UINT32 offset;
UINT32 prefetch;
UINT32 accumulator;
} wBitStream;
#define BITDUMP_MSB_FIRST 0x00000001
#define BITDUMP_STDERR 0x00000002
#ifdef __cplusplus
extern "C"
{
#endif
static INLINE void BitStream_Prefetch(wBitStream* _bs)
{
WINPR_ASSERT(_bs);
(_bs->prefetch) = 0;
if (((UINT32)(_bs->pointer - _bs->buffer) + 4) < (_bs->capacity))
(_bs->prefetch) |= ((UINT32) * (_bs->pointer + 4) << 24);
if (((UINT32)(_bs->pointer - _bs->buffer) + 5) < (_bs->capacity))
(_bs->prefetch) |= ((UINT32) * (_bs->pointer + 5) << 16);
if (((UINT32)(_bs->pointer - _bs->buffer) + 6) < (_bs->capacity))
(_bs->prefetch) |= ((UINT32) * (_bs->pointer + 6) << 8);
if (((UINT32)(_bs->pointer - _bs->buffer) + 7) < (_bs->capacity))
(_bs->prefetch) |= ((UINT32) * (_bs->pointer + 7) << 0);
}
static INLINE void BitStream_Fetch(wBitStream* _bs)
{
WINPR_ASSERT(_bs);
(_bs->accumulator) = 0;
if (((UINT32)(_bs->pointer - _bs->buffer) + 0) < (_bs->capacity))
(_bs->accumulator) |= ((UINT32) * (_bs->pointer + 0) << 24);
if (((UINT32)(_bs->pointer - _bs->buffer) + 1) < (_bs->capacity))
(_bs->accumulator) |= ((UINT32) * (_bs->pointer + 1) << 16);
if (((UINT32)(_bs->pointer - _bs->buffer) + 2) < (_bs->capacity))
(_bs->accumulator) |= ((UINT32) * (_bs->pointer + 2) << 8);
if (((UINT32)(_bs->pointer - _bs->buffer) + 3) < (_bs->capacity))
(_bs->accumulator) |= ((UINT32) * (_bs->pointer + 3) << 0);
BitStream_Prefetch(_bs);
}
static INLINE void BitStream_Flush(wBitStream* _bs)
{
WINPR_ASSERT(_bs);
if (((UINT32)(_bs->pointer - _bs->buffer) + 0) < (_bs->capacity))
*(_bs->pointer + 0) = (BYTE)((UINT32)_bs->accumulator >> 24);
if (((UINT32)(_bs->pointer - _bs->buffer) + 1) < (_bs->capacity))
*(_bs->pointer + 1) = (BYTE)((UINT32)_bs->accumulator >> 16);
if (((UINT32)(_bs->pointer - _bs->buffer) + 2) < (_bs->capacity))
*(_bs->pointer + 2) = (BYTE)((UINT32)_bs->accumulator >> 8);
if (((UINT32)(_bs->pointer - _bs->buffer) + 3) < (_bs->capacity))
*(_bs->pointer + 3) = (BYTE)((UINT32)_bs->accumulator >> 0);
}
static INLINE void BitStream_Shift(wBitStream* _bs, UINT32 _nbits)
{
WINPR_ASSERT(_bs);
if (_nbits == 0)
{
}
else if ((_nbits > 0) && (_nbits < 32))
{
_bs->accumulator <<= _nbits;
_bs->position += _nbits;
_bs->offset += _nbits;
if (_bs->offset < 32)
{
_bs->mask = (UINT32)((1UL << _nbits) - 1UL);
_bs->accumulator |= ((_bs->prefetch >> (32 - _nbits)) & _bs->mask);
_bs->prefetch <<= _nbits;
}
else
{
_bs->mask = (UINT32)((1UL << _nbits) - 1UL);
_bs->accumulator |= ((_bs->prefetch >> (32 - _nbits)) & _bs->mask);
_bs->prefetch <<= _nbits;
_bs->offset -= 32;
_bs->pointer += 4;
BitStream_Prefetch(_bs);
if (_bs->offset)
{
_bs->mask = (UINT32)((1UL << _bs->offset) - 1UL);
_bs->accumulator |= ((_bs->prefetch >> (32 - _bs->offset)) & _bs->mask);
_bs->prefetch <<= _bs->offset;
}
}
}
else
{
WLog_WARN("com.winpr.bitstream", "warning: BitStream_Shift(%u)", (unsigned)_nbits);
}
}
static INLINE void BitStream_Shift32(wBitStream* _bs)
{
WINPR_ASSERT(_bs);
BitStream_Shift(_bs, 16);
BitStream_Shift(_bs, 16);
}
static INLINE void BitStream_Write_Bits(wBitStream* _bs, UINT32 _bits, UINT32 _nbits)
{
WINPR_ASSERT(_bs);
_bs->position += _nbits;
_bs->offset += _nbits;
if (_bs->offset < 32)
{
_bs->accumulator |= (_bits << (32 - _bs->offset));
}
else
{
_bs->offset -= 32;
_bs->mask = ((1 << (_nbits - _bs->offset)) - 1);
_bs->accumulator |= ((_bits >> _bs->offset) & _bs->mask);
BitStream_Flush(_bs);
_bs->accumulator = 0;
_bs->pointer += 4;
if (_bs->offset)
{
_bs->mask = (UINT32)((1UL << _bs->offset) - 1);
_bs->accumulator |= ((_bits & _bs->mask) << (32 - _bs->offset));
}
}
}
static INLINE size_t BitStream_GetRemainingLength(wBitStream* _bs)
{
WINPR_ASSERT(_bs);
return (_bs->length - _bs->position);
}
WINPR_API void BitDump(const char* tag, UINT32 level, const BYTE* buffer, UINT32 length,
UINT32 flags);
WINPR_API UINT32 ReverseBits32(UINT32 bits, UINT32 nbits);
WINPR_API void BitStream_Attach(wBitStream* bs, const BYTE* buffer, UINT32 capacity);
WINPR_API void BitStream_Free(wBitStream* bs);
WINPR_ATTR_MALLOC(BitStream_Free, 1)
WINPR_API wBitStream* BitStream_New(void);
#ifdef __cplusplus
}
#endif
#endif /* WINPR_UTILS_BITSTREAM_H */
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