code.vuplus.com Git - vuplus_xbmc/blob - lib/UnrarXLib/coder.cpp

   1
   2
   3 inline unsigned int RangeCoder::GetChar()
   4 {
   5   return(UnpackRead->GetChar());
   6 }
   7
   8
   9 void RangeCoder::InitDecoder(Unpack *UnpackRead)
  10 {
  11   RangeCoder::UnpackRead=UnpackRead;
  12
  13   low=code=0;
  14   range=uint(-1);
  15   for (int i=0;i < 4;i++)
  16     code=(code << 8) | GetChar();
  17 }
  18
  19
  20 #define ARI_DEC_NORMALIZE(code,low,range,read)                             \
  21 {                                                                          \
  22   while ((low^(low+range))<TOP || (range<BOT && ((range=-low&(BOT-1)),1))) \
  23   {                                                                        \
  24     code=(code << 8) | read->GetChar();                                    \
  25     range <<= 8;                                                           \
  26     low <<= 8;                                                             \
  27   }                                                                        \
  28 }
  29
  30
  31 inline int RangeCoder::GetCurrentCount()
  32 {
  33   return (code-low)/(range /= SubRange.scale);
  34 }
  35
  36
  37 inline uint RangeCoder::GetCurrentShiftCount(uint SHIFT)
  38 {
  39   return (code-low)/(range >>= SHIFT);
  40 }
  41
  42
  43 inline void RangeCoder::Decode()
  44 {
  45   low += range*SubRange.LowCount;
  46   range *= SubRange.HighCount-SubRange.LowCount;
  47 }