FreeRDP/libfreerdp/codec/zgfx.c
2015-05-11 09:07:39 +02:00

415 lines
10 KiB
C

/**
* FreeRDP: A Remote Desktop Protocol Implementation
* ZGFX (RDP8) Bulk Data Compression
*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <winpr/crt.h>
#include <winpr/print.h>
#include <winpr/bitstream.h>
#include <freerdp/codec/zgfx.h>
/**
* RDP8 Compressor Limits:
*
* Maximum number of uncompressed bytes in a single segment: 65535
* Maximum match distance / minimum history size: 2500000 bytes.
* Maximum number of segments: 65535
* Maximum expansion of a segment (when compressed size exceeds uncompressed): 1000 bytes
* Minimum match length: 3 bytes
*/
struct _ZGFX_TOKEN
{
int prefixLength;
int prefixCode;
int valueBits;
int tokenType;
UINT32 valueBase;
};
typedef struct _ZGFX_TOKEN ZGFX_TOKEN;
static const ZGFX_TOKEN ZGFX_TOKEN_TABLE[] =
{
// len code vbits type vbase
{ 1, 0, 8, 0, 0 }, // 0
{ 5, 17, 5, 1, 0 }, // 10001
{ 5, 18, 7, 1, 32 }, // 10010
{ 5, 19, 9, 1, 160 }, // 10011
{ 5, 20, 10, 1, 672 }, // 10100
{ 5, 21, 12, 1, 1696 }, // 10101
{ 5, 24, 0, 0, 0x00 }, // 11000
{ 5, 25, 0, 0, 0x01 }, // 11001
{ 6, 44, 14, 1, 5792 }, // 101100
{ 6, 45, 15, 1, 22176 }, // 101101
{ 6, 52, 0, 0, 0x02 }, // 110100
{ 6, 53, 0, 0, 0x03 }, // 110101
{ 6, 54, 0, 0, 0xFF }, // 110110
{ 7, 92, 18, 1, 54944 }, // 1011100
{ 7, 93, 20, 1, 317088 }, // 1011101
{ 7, 110, 0, 0, 0x04 }, // 1101110
{ 7, 111, 0, 0, 0x05 }, // 1101111
{ 7, 112, 0, 0, 0x06 }, // 1110000
{ 7, 113, 0, 0, 0x07 }, // 1110001
{ 7, 114, 0, 0, 0x08 }, // 1110010
{ 7, 115, 0, 0, 0x09 }, // 1110011
{ 7, 116, 0, 0, 0x0A }, // 1110100
{ 7, 117, 0, 0, 0x0B }, // 1110101
{ 7, 118, 0, 0, 0x3A }, // 1110110
{ 7, 119, 0, 0, 0x3B }, // 1110111
{ 7, 120, 0, 0, 0x3C }, // 1111000
{ 7, 121, 0, 0, 0x3D }, // 1111001
{ 7, 122, 0, 0, 0x3E }, // 1111010
{ 7, 123, 0, 0, 0x3F }, // 1111011
{ 7, 124, 0, 0, 0x40 }, // 1111100
{ 7, 125, 0, 0, 0x80 }, // 1111101
{ 8, 188, 20, 1, 1365664 }, // 10111100
{ 8, 189, 21, 1, 2414240 }, // 10111101
{ 8, 252, 0, 0, 0x0C }, // 11111100
{ 8, 253, 0, 0, 0x38 }, // 11111101
{ 8, 254, 0, 0, 0x39 }, // 11111110
{ 8, 255, 0, 0, 0x66 }, // 11111111
{ 9, 380, 22, 1, 4511392 }, // 101111100
{ 9, 381, 23, 1, 8705696 }, // 101111101
{ 9, 382, 24, 1, 17094304 }, // 101111110
{ 0 }
};
#define zgfx_GetBits(_zgfx, _nbits) \
while (_zgfx->cBitsCurrent < _nbits) { \
_zgfx->BitsCurrent <<= 8; \
if (_zgfx->pbInputCurrent < _zgfx->pbInputEnd) \
_zgfx->BitsCurrent += *(_zgfx->pbInputCurrent)++; \
_zgfx->cBitsCurrent += 8; \
} \
_zgfx->cBitsRemaining -= _nbits; \
_zgfx->cBitsCurrent -= _nbits; \
_zgfx->bits = _zgfx->BitsCurrent >> _zgfx->cBitsCurrent; \
_zgfx->BitsCurrent &= ((1 << _zgfx->cBitsCurrent) - 1);
void zgfx_history_buffer_ring_write(ZGFX_CONTEXT* zgfx, BYTE* src, UINT32 count)
{
UINT32 front;
UINT32 residue;
if (count <= 0)
return;
if (count > zgfx->HistoryBufferSize)
{
residue = count - zgfx->HistoryBufferSize;
count = zgfx->HistoryBufferSize;
src += residue;
zgfx->HistoryIndex = (zgfx->HistoryIndex + residue) % zgfx->HistoryBufferSize;
}
if (zgfx->HistoryIndex + count <= zgfx->HistoryBufferSize)
{
CopyMemory(&(zgfx->HistoryBuffer[zgfx->HistoryIndex]), src, count);
if ((zgfx->HistoryIndex += count) == zgfx->HistoryBufferSize)
zgfx->HistoryIndex = 0;
}
else
{
front = zgfx->HistoryBufferSize - zgfx->HistoryIndex;
CopyMemory(&(zgfx->HistoryBuffer[zgfx->HistoryIndex]), src, front);
CopyMemory(zgfx->HistoryBuffer, &src[front], count - front);
zgfx->HistoryIndex = count - front;
}
}
void zgfx_history_buffer_ring_read(ZGFX_CONTEXT* zgfx, int offset, BYTE* dst, UINT32 count)
{
UINT32 front;
UINT32 index;
UINT32 bytes;
UINT32 valid;
UINT32 bytesLeft;
BYTE* dptr = dst;
BYTE* origDst = dst;
if (count <= 0)
return;
bytesLeft = count;
index = (zgfx->HistoryIndex + zgfx->HistoryBufferSize - offset) % zgfx->HistoryBufferSize;
bytes = MIN(bytesLeft, offset);
if ((index + bytes) <= zgfx->HistoryBufferSize)
{
CopyMemory(dptr, &(zgfx->HistoryBuffer[index]), bytes);
}
else
{
front = zgfx->HistoryBufferSize - index;
CopyMemory(dptr, &(zgfx->HistoryBuffer[index]), front);
CopyMemory(&dptr[front], zgfx->HistoryBuffer, bytes - front);
}
if ((bytesLeft -= bytes) == 0)
return;
dptr += bytes;
valid = bytes;
do
{
bytes = valid;
if (bytes > bytesLeft)
bytes = bytesLeft;
CopyMemory(dptr, origDst, bytes);
dptr += bytes;
valid <<= 1;
}
while ((bytesLeft -= bytes) > 0);
}
int zgfx_decompress_segment(ZGFX_CONTEXT* zgfx, BYTE* pbSegment, UINT32 cbSegment)
{
BYTE c;
BYTE flags;
int extra;
int opIndex;
int haveBits;
int inPrefix;
UINT32 count;
UINT32 distance;
if (cbSegment < 1)
return -1;
flags = pbSegment[0]; /* header (1 byte) */
pbSegment++;
cbSegment--;
zgfx->OutputCount = 0;
if (!(flags & PACKET_COMPRESSED))
{
zgfx_history_buffer_ring_write(zgfx, pbSegment, cbSegment);
CopyMemory(zgfx->OutputBuffer, pbSegment, cbSegment);
zgfx->OutputCount = cbSegment;
return 1;
}
zgfx->pbInputCurrent = pbSegment;
zgfx->pbInputEnd = &pbSegment[cbSegment - 1];
/* NumberOfBitsToDecode = ((NumberOfBytesToDecode - 1) * 8) - ValueOfLastByte */
zgfx->cBitsRemaining = 8 * (cbSegment - 1) - *zgfx->pbInputEnd;
zgfx->cBitsCurrent = 0;
zgfx->BitsCurrent = 0;
while (zgfx->cBitsRemaining)
{
haveBits = 0;
inPrefix = 0;
for (opIndex = 0; ZGFX_TOKEN_TABLE[opIndex].prefixLength != 0; opIndex++)
{
while (haveBits < ZGFX_TOKEN_TABLE[opIndex].prefixLength)
{
zgfx_GetBits(zgfx, 1);
inPrefix = (inPrefix << 1) + zgfx->bits;
haveBits++;
}
if (inPrefix == ZGFX_TOKEN_TABLE[opIndex].prefixCode)
{
if (ZGFX_TOKEN_TABLE[opIndex].tokenType == 0)
{
/* Literal */
zgfx_GetBits(zgfx, ZGFX_TOKEN_TABLE[opIndex].valueBits);
c = (BYTE) (ZGFX_TOKEN_TABLE[opIndex].valueBase + zgfx->bits);
zgfx->HistoryBuffer[zgfx->HistoryIndex] = c;
if (++zgfx->HistoryIndex == zgfx->HistoryBufferSize)
zgfx->HistoryIndex = 0;
zgfx->OutputBuffer[zgfx->OutputCount++] = c;
}
else
{
zgfx_GetBits(zgfx, ZGFX_TOKEN_TABLE[opIndex].valueBits);
distance = ZGFX_TOKEN_TABLE[opIndex].valueBase + zgfx->bits;
if (distance != 0)
{
/* Match */
zgfx_GetBits(zgfx, 1);
if (zgfx->bits == 0)
{
count = 3;
}
else
{
count = 4;
extra = 2;
zgfx_GetBits(zgfx, 1);
while (zgfx->bits == 1)
{
count *= 2;
extra++;
zgfx_GetBits(zgfx, 1);
}
zgfx_GetBits(zgfx, extra);
count += zgfx->bits;
}
zgfx_history_buffer_ring_read(zgfx, distance, &(zgfx->OutputBuffer[zgfx->OutputCount]), count);
zgfx_history_buffer_ring_write(zgfx, &(zgfx->OutputBuffer[zgfx->OutputCount]), count);
zgfx->OutputCount += count;
}
else
{
/* Unencoded */
zgfx_GetBits(zgfx, 15);
count = zgfx->bits;
zgfx->cBitsRemaining -= zgfx->cBitsCurrent;
zgfx->cBitsCurrent = 0;
zgfx->BitsCurrent = 0;
CopyMemory(&(zgfx->OutputBuffer[zgfx->OutputCount]), zgfx->pbInputCurrent, count);
zgfx_history_buffer_ring_write(zgfx, zgfx->pbInputCurrent, count);
zgfx->pbInputCurrent += count;
zgfx->cBitsRemaining -= (8 * count);
zgfx->OutputCount += count;
}
}
break;
}
}
}
return 1;
}
int zgfx_decompress(ZGFX_CONTEXT* zgfx, BYTE* pSrcData, UINT32 SrcSize, BYTE** ppDstData, UINT32* pDstSize, UINT32 flags)
{
int status;
BYTE descriptor;
if (SrcSize < 1)
return -1;
descriptor = pSrcData[0]; /* descriptor (1 byte) */
if (descriptor == ZGFX_SEGMENTED_SINGLE)
{
status = zgfx_decompress_segment(zgfx, &pSrcData[1], SrcSize - 1);
*ppDstData = (BYTE*) malloc(zgfx->OutputCount);
*pDstSize = zgfx->OutputCount;
CopyMemory(*ppDstData, zgfx->OutputBuffer, zgfx->OutputCount);
}
else if (descriptor == ZGFX_SEGMENTED_MULTIPART)
{
UINT32 segmentSize;
UINT16 segmentNumber;
UINT16 segmentCount;
UINT32 segmentOffset;
UINT32 uncompressedSize;
BYTE* pConcatenated;
segmentOffset = 7;
segmentCount = *((UINT16*) &pSrcData[1]); /* segmentCount (2 bytes) */
uncompressedSize = *((UINT32*) &pSrcData[3]); /* uncompressedSize (4 bytes) */
pConcatenated = (BYTE*) malloc(uncompressedSize);
*ppDstData = pConcatenated;
*pDstSize = uncompressedSize;
for (segmentNumber = 0; segmentNumber < segmentCount; segmentNumber++)
{
segmentSize = *((UINT32*) &pSrcData[segmentOffset]); /* segmentSize (4 bytes) */
segmentOffset += 4;
status = zgfx_decompress_segment(zgfx, &pSrcData[segmentOffset], segmentSize);
segmentOffset += segmentSize;
CopyMemory(pConcatenated, zgfx->OutputBuffer, zgfx->OutputCount);
pConcatenated += zgfx->OutputCount;
}
}
else
{
return -1;
}
return 1;
}
int zgfx_compress(ZGFX_CONTEXT* zgfx, BYTE* pSrcData, UINT32 SrcSize, BYTE** ppDstData, UINT32* pDstSize, UINT32* pFlags)
{
return 1;
}
void zgfx_context_reset(ZGFX_CONTEXT* zgfx, BOOL flush)
{
zgfx->HistoryIndex = 0;
}
ZGFX_CONTEXT* zgfx_context_new(BOOL Compressor)
{
ZGFX_CONTEXT* zgfx;
zgfx = (ZGFX_CONTEXT*) calloc(1, sizeof(ZGFX_CONTEXT));
if (zgfx)
{
zgfx->Compressor = Compressor;
zgfx->HistoryBufferSize = sizeof(zgfx->HistoryBuffer);
zgfx_context_reset(zgfx, FALSE);
}
return zgfx;
}
void zgfx_context_free(ZGFX_CONTEXT* zgfx)
{
free(zgfx);
}