BitVector.hh

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FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
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// "liveMedia"
// Copyright (c) 1996-2024 Live Networks, Inc.  All rights reserved.
// Bit Vector data structure
// C++ header
 
#ifndef _BIT_VECTOR_HH
#define _BIT_VECTOR_HH
 
#ifndef _BOOLEAN_HH
#include "Boolean.hh"
#endif
 
class BitVector {
public:
  BitVector(unsigned char* baseBytePtr,
            unsigned baseBitOffset,
            unsigned totNumBits);
 
  void setup(unsigned char* baseBytePtr,
             unsigned baseBitOffset,
             unsigned totNumBits);
 
  void putBits(unsigned from, unsigned numBits); // "numBits" <= 32
  void put1Bit(unsigned bit);
 
  unsigned getBits(unsigned numBits); // "numBits" <= 32
  unsigned get1Bit();
  Boolean get1BitBoolean() { return get1Bit() != 0; }
 
  void skipBits(unsigned numBits);
 
  unsigned curBitIndex() const { return fCurBitIndex; }
  unsigned totNumBits() const { return fTotNumBits; }
  unsigned numBitsRemaining() const { return fTotNumBits - fCurBitIndex; }
 
  unsigned get_expGolomb();
      // Returns the value of the next bits, assuming that they were encoded using an exponential-Golomb code of order 0
  int get_expGolombSigned(); // signed version of the above
 
private:
  unsigned char* fBaseBytePtr;
  unsigned fBaseBitOffset;
  unsigned fTotNumBits;
  unsigned fCurBitIndex;
};
 
// A general bit copy operation:
void shiftBits(unsigned char* toBasePtr, unsigned toBitOffset,
               unsigned char const* fromBasePtr, unsigned fromBitOffset,
               unsigned numBits);
 
#endif