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libfreerdp-codec: initial RDP5 MPPC LOM/CO encoding

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This commit is contained in:
Marc-André Moreau 2014-03-05 16:28:53 -05:00
parent cea902deb8
commit a711132cd9
1 changed files with 120 additions and 0 deletions
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120
libfreerdp/codec/mppc.c
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@ -82,6 +82,7 @@ int mppc_compress(MPPC_CONTEXT* mppc, BYTE* pSrcData, BYTE* pDstData, int size)
if (((mppc->HistoryOffset + size) < (mppc->HistoryBufferSize - 3)) /* && mppc->HistoryOffset */)
{
/* SrcData fits into HistoryBuffer? (YES) */
CopyMemory(&(mppc->HistoryBuffer[mppc->HistoryOffset]), pSrcData, size);
mppc->HistoryPtr = 0;
@ -164,6 +165,125 @@ int mppc_compress(MPPC_CONTEXT* mppc, BYTE* pSrcData, BYTE* pDstData, int size)
printf("<%d,%d>", (int) CopyOffset, (int) LengthOfMatch);
/* Encode CopyOffset */
if (CopyOffset < 64)
{
/* 11111 + lower 6 bits of CopyOffset */
accumulator = 0x07C0 | (CopyOffset & 0x003F);
BitStream_Write_Bits(mppc->bs, accumulator, 11);
}
else if ((CopyOffset >= 64) && (CopyOffset < 320))
{
/* 11110 + lower 8 bits of (CopyOffset - 64) */
accumulator = 0x1E00 | ((CopyOffset - 64) & 0x00FF);
BitStream_Write_Bits(mppc->bs, accumulator, 13);
}
else if ((CopyOffset >= 320) && (CopyOffset < 2368))
{
/* 1110 + lower 11 bits of (CopyOffset - 320) */
accumulator = 0x7000 | ((CopyOffset - 320) & 0x07FF);
BitStream_Write_Bits(mppc->bs, accumulator, 15);
}
else
{
/* 110 + lower 16 bits of (CopyOffset - 2368) */
accumulator = 0x060000 | ((CopyOffset - 2368) & 0xFFFF);
BitStream_Write_Bits(mppc->bs, accumulator, 19);
}
/* Encode LengthOfMatch */
if (LengthOfMatch == 3)
{
/* 0 + 0 lower bits of LengthOfMatch */
BitStream_Write_Bits(mppc->bs, 0, 1);
}
else if ((LengthOfMatch >= 4) && (LengthOfMatch < 8))
{
/* 10 + 2 lower bits of LengthOfMatch */
accumulator = 0x0008 | (LengthOfMatch & 0x0003);
BitStream_Write_Bits(mppc->bs, accumulator, 4);
}
else if ((LengthOfMatch >= 8) && (LengthOfMatch < 16))
{
/* 110 + 3 lower bits of LengthOfMatch */
accumulator = 0x0030 | (LengthOfMatch & 0x0007);
BitStream_Write_Bits(mppc->bs, accumulator, 6);
}
else if ((LengthOfMatch >= 16) && (LengthOfMatch < 32))
{
/* 1110 + 4 lower bits of LengthOfMatch */
accumulator = 0x00E0 | (LengthOfMatch & 0x000F);
BitStream_Write_Bits(mppc->bs, accumulator, 8);
}
else if ((LengthOfMatch >= 32) && (LengthOfMatch < 64))
{
/* 11110 + 5 lower bits of LengthOfMatch */
accumulator = 0x03C0 | (LengthOfMatch & 0x001F);
BitStream_Write_Bits(mppc->bs, accumulator, 10);
}
else if ((LengthOfMatch >= 64) && (LengthOfMatch < 128))
{
/* 111110 + 6 lower bits of LengthOfMatch */
accumulator = 0x0F80 | (LengthOfMatch & 0x003F);
BitStream_Write_Bits(mppc->bs, accumulator, 12);
}
else if ((LengthOfMatch >= 128) && (LengthOfMatch < 256))
{
/* 1111110 + 7 lower bits of LengthOfMatch */
accumulator = 0x3F00 | (LengthOfMatch & 0x007F);
BitStream_Write_Bits(mppc->bs, accumulator, 14);
}
else if ((LengthOfMatch >= 256) && (LengthOfMatch < 512))
{
/* 11111110 + 8 lower bits of LengthOfMatch */
accumulator = 0xFE00 | (LengthOfMatch & 0x00FF);
BitStream_Write_Bits(mppc->bs, accumulator, 16);
}
else if ((LengthOfMatch >= 512) && (LengthOfMatch < 1024))
{
/* 111111110 + 9 lower bits of LengthOfMatch */
accumulator = 0x3FC00 | (LengthOfMatch & 0x01FF);
BitStream_Write_Bits(mppc->bs, accumulator, 18);
}
else if ((LengthOfMatch >= 1024) && (LengthOfMatch < 2048))
{
/* 1111111110 + 10 lower bits of LengthOfMatch */
accumulator = 0xFF800 | (LengthOfMatch & 0x03FF);
BitStream_Write_Bits(mppc->bs, accumulator, 20);
}
else if ((LengthOfMatch >= 2048) && (LengthOfMatch < 4096))
{
/* 11111111110 + 11 lower bits of LengthOfMatch */
accumulator = 0x3FF000 | (LengthOfMatch & 0x07FF);
BitStream_Write_Bits(mppc->bs, accumulator, 22);
}
else if ((LengthOfMatch >= 4096) && (LengthOfMatch < 8192))
{
/* 111111111110 + 12 lower bits of LengthOfMatch */
accumulator = 0xFFE000 | (LengthOfMatch & 0x0FFF);
BitStream_Write_Bits(mppc->bs, accumulator, 24);
}
else if ((LengthOfMatch >= 8192) && (LengthOfMatch < 16384))
{
/* 1111111111110 + 13 lower bits of LengthOfMatch */
accumulator = 0x3FFC000 | (LengthOfMatch & 0x1FFF);
BitStream_Write_Bits(mppc->bs, accumulator, 26);
}
else if ((LengthOfMatch >= 16384) && (LengthOfMatch < 32768))
{
/* 11111111111110 + 14 lower bits of LengthOfMatch */
accumulator = 0xFFF8000 | (LengthOfMatch & 0x3FFF);
BitStream_Write_Bits(mppc->bs, accumulator, 28);
}
else if ((LengthOfMatch >= 32768) && (LengthOfMatch < 65536))
{
/* 111111111111110 + 15 lower bits of LengthOfMatch */
accumulator = 0x3FFF0000 | (LengthOfMatch & 0x7FFF);
BitStream_Write_Bits(mppc->bs, accumulator, 30);
}
mppc->HistoryPtr += LengthOfMatch;
mppc->pHistoryPtr = &(mppc->HistoryBuffer[mppc->HistoryPtr]);
}