libfreerdp-codec: add NCrush offset cache decoding

diff --git a/libfreerdp/codec/ncrush.c b/libfreerdp/codec/ncrush.c
index 5b248d8..4d69fd3 100644 (file)
--- a/libfreerdp/codec/ncrush.c
+++ b/libfreerdp/codec/ncrush.c
@@ -1124,12 +1124,12 @@ int ncrush_decompress(NCRUSH_CONTEXT* ncrush, BYTE* pSrcData, UINT32 SrcSize, BY
        BYTE Literal;
        UINT32 BitLength;
        UINT32 MaskedBits;
-       UINT32 CopyOffset = 0;
-       UINT32 LengthOfMatch = 0;
+       UINT32 CopyOffset;
+       UINT32 OldCopyOffset;
+       UINT32 LengthOfMatch;
        UINT32 CopyOffsetIndex;
        UINT32 OffsetCacheIndex;
        BYTE* HistoryPtr;
-       UINT32 HistoryOffset;
        BYTE* HistoryBuffer;
        BYTE* HistoryBufferEnd;
        UINT32 HistoryBufferSize;
@@ -1149,28 +1149,23 @@ int ncrush_decompress(NCRUSH_CONTEXT* ncrush, BYTE* pSrcData, UINT32 SrcSize, BY
                        return -1;
 
                CopyMemory(HistoryBuffer, (ncrush->HistoryPtr - 32768), 32768);
-               ncrush->HistoryOffset = 32768;
-               ncrush->HistoryPtr = &(HistoryBuffer[ncrush->HistoryOffset]);
+               ncrush->HistoryPtr = &(HistoryBuffer[32768]);
        }
 
        if (flags & PACKET_FLUSHED)
        {
-               ncrush->HistoryOffset = 0;
                ncrush->HistoryPtr = HistoryBuffer;
                ZeroMemory(HistoryBuffer, ncrush->HistoryBufferSize);
                ZeroMemory(&(ncrush->OffsetCache), sizeof(ncrush->OffsetCache));
        }
 
        HistoryPtr = ncrush->HistoryPtr;
-       HistoryOffset = ncrush->HistoryOffset;
 
        if (!(flags & PACKET_COMPRESSED))
        {
                CopyMemory(HistoryPtr, pSrcData, SrcSize);
                HistoryPtr += SrcSize;
-               HistoryOffset += SrcSize;
                ncrush->HistoryPtr = HistoryPtr;
-               ncrush->HistoryOffset = HistoryOffset;
                *ppDstData = HistoryPtr;
                *pDstSize = SrcSize;
                return 1;
@@ -1222,9 +1217,38 @@ int ncrush_decompress(NCRUSH_CONTEXT* ncrush, BYTE* pSrcData, UINT32 SrcSize, BY
                        if (OffsetCacheIndex >= 4)
                                return -1;
 
-                       printf("\nOffsetCacheIndex: %d\n", OffsetCacheIndex);
+                       CopyOffset = ncrush->OffsetCache[OffsetCacheIndex];
+
+                       Mask = *((UINT16*) &HuffTableMask[21]);
+                       MaskedBits = bits & Mask;
+
+                       LengthOfMatch = HuffTableLOM[MaskedBits] & 0xFFF;
+                       BitLength = HuffTableLOM[MaskedBits] >> 12;
+
+                       bits >>= BitLength;
+                       nbits -= BitLength;
+
+                       NCrushFetchBits();
+
+                       LengthOfMatchBits = LOMBitsLUT[LengthOfMatch];
+                       LengthOfMatchBase = LOMBaseLUT[LengthOfMatch];
+
+                       if (LengthOfMatchBits)
+                       {
+                               Mask = *((UINT16*) &HuffTableMask[(2 * LengthOfMatchBits) + 3]);
+                               MaskedBits = bits & Mask;
+
+                               LengthOfMatchBase += MaskedBits;
+
+                               bits >>= LengthOfMatchBits;
+                               nbits -= LengthOfMatchBits;
+
+                               NCrushFetchBits();
+                       }
 
-                       return -1; /* TODO */
+                       OldCopyOffset = ncrush->OffsetCache[OffsetCacheIndex];
+                       ncrush->OffsetCache[OffsetCacheIndex] = ncrush->OffsetCache[0];
+                       ncrush->OffsetCache[0] = OldCopyOffset;
                }
                else
                {