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libfreerdp-codec: produce correct LOM/CO sequences

This commit is contained in:
Marc-André Moreau 2014-03-05 15:29:04 -05:00
parent dbe7e7aae2
commit cea902deb8
3 changed files with 69 additions and 19 deletions
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3
include/freerdp/codec/mppc.h
View File

@ -23,9 +23,12 @@
#include <freerdp/api.h>
#include <freerdp/types.h>
#include <winpr/collections.h>
struct _MPPC_CONTEXT
{
DWORD Flags;
wBitStream* bs;
BOOL Compressor;
DWORD HistoryPtr;
BYTE* pHistoryPtr;

84
libfreerdp/codec/mppc.c
View File

@ -23,12 +23,16 @@
#include <winpr/crt.h>
#include <winpr/print.h>
#include <winpr/collections.h>
#include <freerdp/codec/mppc_enc.h>
#include <freerdp/codec/mppc_dec.h>
#include <freerdp/codec/mppc.h>
#define MPPC_MATCH_INDEX(_sym1, _sym2, _sym3) \
((((MPPC_MATCH_TABLE[_sym3] << 16) + (MPPC_MATCH_TABLE[_sym2] << 8) + MPPC_MATCH_TABLE[_sym1]) & 0x07FFF000) >> 12)
const UINT32 MPPC_MATCH_TABLE[256] =
{
0x00000000, 0x009CCF93, 0x01399F26, 0x01D66EB9, 0x02733E4C, 0x03100DDF, 0x03ACDD72, 0x0449AD05,
@ -70,8 +74,10 @@ int mppc_compress(MPPC_CONTEXT* mppc, BYTE* pSrcData, BYTE* pDstData, int size)
DWORD Flags = 0;
BYTE* pMatch;
DWORD MatchIndex;
UINT32 accumulator;
BYTE* pEnd;
//BYTE* OutputBuffer = pDstData;
BitStream_Attach(mppc->bs, pDstData, size);
if (((mppc->HistoryOffset + size) < (mppc->HistoryBufferSize - 3)) /* && mppc->HistoryOffset */)
{
@ -108,27 +114,32 @@ int mppc_compress(MPPC_CONTEXT* mppc, BYTE* pSrcData, BYTE* pDstData, int size)
pEnd = &(mppc->HistoryBuffer[size - 1]);
int index = 0;
while (mppc->pHistoryPtr < (pEnd - 2))
{
MatchIndex = ((((MPPC_MATCH_TABLE[mppc->pHistoryPtr[2]] << 16) +
(MPPC_MATCH_TABLE[mppc->pHistoryPtr[1]] << 8) +
MPPC_MATCH_TABLE[mppc->pHistoryPtr[0]]) & 0x07FFF000) >> 12);
MatchIndex = MPPC_MATCH_INDEX(mppc->pHistoryPtr[0], mppc->pHistoryPtr[1], mppc->pHistoryPtr[2]);
pMatch = &(mppc->HistoryBuffer[mppc->MatchBuffer[MatchIndex]]);
mppc->MatchBuffer[MatchIndex] = (UINT16) mppc->HistoryPtr;
printf("[%d] MatchIndex: %d pMatch: %p pHistoryPtr: %p HistoryPtr: %d\n",
index, (int) MatchIndex, pMatch, mppc->pHistoryPtr, (int) mppc->HistoryPtr);
if ((mppc->pHistoryPtr[0] != pMatch[0]) || (mppc->pHistoryPtr[1] != pMatch[1])
|| (mppc->pHistoryPtr[2] != pMatch[2]) || (mppc->pHistoryPtr == pMatch))
if ((mppc->pHistoryPtr[0] != pMatch[0]) || (mppc->pHistoryPtr[1] != pMatch[1]) ||
(mppc->pHistoryPtr[2] != pMatch[2]) || (mppc->pHistoryPtr == pMatch))
{
printf("no match: %c%c%c %c%c%c\n",
mppc->pHistoryPtr[0], mppc->pHistoryPtr[1], mppc->pHistoryPtr[2],
pMatch[0], pMatch[1], pMatch[2]);
accumulator = *(mppc->pHistoryPtr);
printf("%c", accumulator);
if (accumulator < 0x80)
{
/* 8 bits of literal are encoded as-is */
BitStream_Write_Bits(mppc->bs, accumulator, 8);
}
else
{
/* bits 10 followed by lower 7 bits of literal */
accumulator = 0x100 | (accumulator & 0x7F);
BitStream_Write_Bits(mppc->bs, accumulator, 9);
}
mppc->HistoryPtr++;
mppc->pHistoryPtr = &(mppc->HistoryBuffer[mppc->HistoryPtr]);
@ -136,25 +147,56 @@ int mppc_compress(MPPC_CONTEXT* mppc, BYTE* pSrcData, BYTE* pDstData, int size)
else
{
DWORD CopyOffset;
DWORD LengthOfMatch = 3;
DWORD LengthOfMatch = 1;
CopyOffset = (DWORD) (mppc->pHistoryPtr - pMatch);
while ((mppc->pHistoryPtr[LengthOfMatch] == pMatch[LengthOfMatch]) &&
((mppc->HistoryPtr + LengthOfMatch) < (size - 1)))
{
MatchIndex = MPPC_MATCH_INDEX(mppc->pHistoryPtr[LengthOfMatch],
mppc->pHistoryPtr[LengthOfMatch + 1], mppc->pHistoryPtr[LengthOfMatch + 2]);
mppc->MatchBuffer[MatchIndex] = (UINT16) (mppc->HistoryPtr + LengthOfMatch);
LengthOfMatch++;
}
printf("MATCH: <%d, %d> %.*s\n",
(int) CopyOffset, (int) LengthOfMatch,
(int) LengthOfMatch, pMatch);
printf("<%d,%d>", (int) CopyOffset, (int) LengthOfMatch);
mppc->HistoryPtr += LengthOfMatch;
mppc->pHistoryPtr = &(mppc->HistoryBuffer[mppc->HistoryPtr]);
}
}
index++;
/* Encode trailing symbols as literals */
while (mppc->pHistoryPtr <= pEnd)
{
MatchIndex = MPPC_MATCH_INDEX(mppc->pHistoryPtr[0], mppc->pHistoryPtr[1], mppc->pHistoryPtr[2]);
pMatch = &(mppc->HistoryBuffer[mppc->MatchBuffer[MatchIndex]]);
mppc->MatchBuffer[MatchIndex] = (UINT16) mppc->HistoryPtr;
accumulator = *(mppc->pHistoryPtr);
printf("%c", accumulator);
if (accumulator < 0x80)
{
/* 8 bits of literal are encoded as-is */
BitStream_Write_Bits(mppc->bs, accumulator, 8);
}
else
{
/* bits 10 followed by lower 7 bits of literal */
accumulator = 0x100 | (accumulator & 0x7F);
BitStream_Write_Bits(mppc->bs, accumulator, 9);
}
mppc->HistoryPtr++;
mppc->pHistoryPtr = &(mppc->HistoryBuffer[mppc->HistoryPtr]);
}
}
else
@ -193,6 +235,8 @@ MPPC_CONTEXT* mppc_context_new(DWORD CompressionLevel, BOOL Compressor)
ZeroMemory(&(mppc->HistoryBuffer), sizeof(mppc->HistoryBuffer));
ZeroMemory(&(mppc->MatchBuffer), sizeof(mppc->MatchBuffer));
mppc->bs = BitStream_New();
}
return mppc;
@ -202,6 +246,8 @@ void mppc_context_free(MPPC_CONTEXT* mppc)
{
if (mppc)
{
BitStream_Free(mppc->bs);
free(mppc);
}
}

1
libfreerdp/codec/test/TestFreeRDPCodecMppc.c
View File

@ -701,6 +701,7 @@ int TestFreeRDPCodecMppc(int argc, char* argv[])
printf("%s\n", pSrcData);
mppc_compress(mppc, pSrcData, OutputBuffer, size);
printf("\n");
mppc_context_free(mppc);