// ************************************************************************************************* // -------------------------------------- // Copyright (C) 2006-2010 Rajko Stojadinovic // // // This program is free software; you can redistribute it and/or // modify it under the terms of the GNU Lesser General Public // License as published by the Free Software Foundation; either // version 2.1 of the License, or (at your option) any later version. // // This program is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU // Lesser General Public License for more details. // // You should have received a copy of the GNU Lesser General Public // License along with this library; if not, write to the Free Software // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA // // ************************************************************************************************* #include "BitStream.h" #include #include #include #if defined(_WIN32) #include // htonl #include #include #include #else #include #include #include #include #endif // MSWin uses _copysign, others use copysign... #ifndef _WIN32 #define _copysign copysign #endif #ifdef _MSC_VER #pragma warning( push ) #endif BitStream::BitStream() { numberOfBitsUsed = 0; //numberOfBitsAllocated = 32 * 8; numberOfBitsAllocated = BITSTREAM_STACK_ALLOCATION_SIZE * 8; readOffset = 0; //data = ( unsigned char* ) malloc( 32 ); data = ( unsigned char* ) stackData; #ifdef _DEBUG //assert( data ); #endif //memset(data, 0, 32); copyData = true; } BitStream::BitStream( const unsigned int initialBytesToAllocate ) { numberOfBitsUsed = 0; readOffset = 0; if (initialBytesToAllocate <= BITSTREAM_STACK_ALLOCATION_SIZE) { data = ( unsigned char* ) stackData; numberOfBitsAllocated = BITSTREAM_STACK_ALLOCATION_SIZE * 8; } else { data = ( unsigned char* ) malloc( (size_t) initialBytesToAllocate ); numberOfBitsAllocated = initialBytesToAllocate << 3; } #ifdef _DEBUG assert( data ); #endif // memset(data, 0, initialBytesToAllocate); copyData = true; } BitStream::BitStream( unsigned char* _data, const unsigned int lengthInBytes, bool _copyData ) { numberOfBitsUsed = lengthInBytes << 3; readOffset = 0; copyData = _copyData; numberOfBitsAllocated = lengthInBytes << 3; if ( copyData ) { if ( lengthInBytes > 0 ) { if (lengthInBytes < BITSTREAM_STACK_ALLOCATION_SIZE) { data = ( unsigned char* ) stackData; numberOfBitsAllocated = BITSTREAM_STACK_ALLOCATION_SIZE << 3; } else { data = ( unsigned char* ) malloc( (size_t) lengthInBytes); } #ifdef _DEBUG assert( data ); #endif memcpy( data, _data, (size_t) lengthInBytes ); } else data = 0; } else data = ( unsigned char* ) _data; } // Use this if you pass a pointer copy to the constructor (_copyData==false) and want to overallocate to prevent reallocation void BitStream::SetNumberOfBitsAllocated( const uint32 lengthInBits ) { #ifdef _DEBUG assert( lengthInBits >= ( uint32 ) numberOfBitsAllocated ); #endif numberOfBitsAllocated = lengthInBits; } BitStream::~BitStream() { if ( copyData && numberOfBitsAllocated > (BITSTREAM_STACK_ALLOCATION_SIZE << 3)) free(data); // Use realloc and free so we are more efficient than delete and new for resizing } void BitStream::Reset( void ) { // Note: Do NOT reallocate memory because BitStream is used // in places to serialize/deserialize a buffer. Reallocation // is a dangerous operation (may result in leaks). if ( numberOfBitsUsed > 0 ) { // memset(data, 0, BITS_TO_BYTES(numberOfBitsUsed)); } // Don't free memory here for speed efficiency //free(data); // Use realloc and free so we are more efficient than delete and new for resizing numberOfBitsUsed = 0; //numberOfBitsAllocated=8; readOffset = 0; //data=(unsigned char*)malloc(1,); // if (numberOfBitsAllocated>0) // memset(data, 0, BITS_TO_BYTES(numberOfBitsAllocated)); } // Write an array or casted stream void BitStream::Write( const char* input, const unsigned int numberOfBytes ) { if (numberOfBytes==0) return; // Optimization: if ((numberOfBitsUsed & 7) == 0) { AddBitsAndReallocate( BYTES_TO_BITS(numberOfBytes) ); memcpy(data+BITS_TO_BYTES(numberOfBitsUsed), input, (size_t) numberOfBytes); numberOfBitsUsed+=BYTES_TO_BITS(numberOfBytes); } else { WriteBits( ( unsigned char* ) input, numberOfBytes * 8, true ); } } void BitStream::Write( BitStream *bitStream) { Write(bitStream, bitStream->GetNumberOfBitsUsed()); } void BitStream::Write( BitStream *bitStream, uint32 numberOfBits ) { AddBitsAndReallocate( numberOfBits ); uint32 numberOfBitsMod8; if ((bitStream->GetReadOffset()&7)==0 && (numberOfBitsUsed&7)==0) { int readOffsetBytes=bitStream->GetReadOffset()/8; int numBytes=numberOfBits/8; memcpy(data + (numberOfBitsUsed >> 3), bitStream->GetData()+readOffsetBytes, numBytes); numberOfBits-=BYTES_TO_BITS(numBytes); bitStream->SetReadOffset(BYTES_TO_BITS(numBytes+readOffsetBytes)); numberOfBitsUsed+=BYTES_TO_BITS(numBytes); } while (numberOfBits-->0 && bitStream->readOffset + 1 <= bitStream->numberOfBitsUsed) { numberOfBitsMod8 = numberOfBitsUsed & 7; if ( numberOfBitsMod8 == 0 ) { // New byte if (bitStream->data[ bitStream->readOffset >> 3 ] & ( 0x80 >> ( bitStream->readOffset & 7 ) ) ) { // Write 1 data[ numberOfBitsUsed >> 3 ] = 0x80; } else { // Write 0 data[ numberOfBitsUsed >> 3 ] = 0; } } else { // Existing byte if (bitStream->data[ bitStream->readOffset >> 3 ] & ( 0x80 >> ( bitStream->readOffset & 7 ) ) ) data[ numberOfBitsUsed >> 3 ] |= 0x80 >> ( numberOfBitsMod8 ); // Set the bit to 1 // else 0, do nothing } bitStream->readOffset++; numberOfBitsUsed++; } } void BitStream::Write( BitStream &bitStream, uint32 numberOfBits ) { Write(&bitStream, numberOfBits); } void BitStream::Write( BitStream &bitStream ) { Write(&bitStream); } bool BitStream::Read( BitStream *bitStream, uint32 numberOfBits ) { if (GetNumberOfUnreadBits() < numberOfBits) return false; bitStream->Write(this, numberOfBits); return true; } bool BitStream::Read( BitStream *bitStream ) { bitStream->Write(this); return true; } bool BitStream::Read( BitStream &bitStream, uint32 numberOfBits ) { if (GetNumberOfUnreadBits() < numberOfBits) return false; bitStream.Write(this, numberOfBits); return true; } bool BitStream::Read( BitStream &bitStream ) { bitStream.Write(this); return true; } // Read an array or casted stream bool BitStream::Read( char* output, const unsigned int numberOfBytes ) { // Optimization: if ((readOffset & 7) == 0) { if ( readOffset + ( numberOfBytes << 3 ) > numberOfBitsUsed ) return false; // Write the data memcpy( output, data + ( readOffset >> 3 ), (size_t) numberOfBytes ); readOffset += numberOfBytes << 3; return true; } else { return ReadBits( ( unsigned char* ) output, numberOfBytes * 8 ); } } // Sets the read pointer back to the beginning of your data. void BitStream::ResetReadPointer( void ) { readOffset = 0; } // Sets the write pointer back to the beginning of your data. void BitStream::ResetWritePointer( void ) { numberOfBitsUsed = 0; } // Write a 0 void BitStream::Write0( void ) { AddBitsAndReallocate( 1 ); // New bytes need to be zeroed if ( ( numberOfBitsUsed & 7 ) == 0 ) data[ numberOfBitsUsed >> 3 ] = 0; numberOfBitsUsed++; } // Write a 1 void BitStream::Write1( void ) { AddBitsAndReallocate( 1 ); uint32 numberOfBitsMod8 = numberOfBitsUsed & 7; if ( numberOfBitsMod8 == 0 ) data[ numberOfBitsUsed >> 3 ] = 0x80; else data[ numberOfBitsUsed >> 3 ] |= 0x80 >> ( numberOfBitsMod8 ); // Set the bit to 1 numberOfBitsUsed++; } // Returns true if the next data read is a 1, false if it is a 0 bool BitStream::ReadBit( void ) { bool result = ( data[ readOffset >> 3 ] & ( 0x80 >> ( readOffset & 7 ) ) ) !=0; readOffset++; return result; } // Align the bitstream to the byte boundary and then write the specified number of bits. // This is faster than WriteBits but wastes the bits to do the alignment and requires you to call // SetReadToByteAlignment at the corresponding read position void BitStream::WriteAlignedBytes( const unsigned char* input, const unsigned int numberOfBytesToWrite ) { AlignWriteToByteBoundary(); Write((const char*) input, numberOfBytesToWrite); } /// Aligns the bitstream, writes inputLength, and writes input. Won't write beyond maxBytesToWrite void BitStream::WriteAlignedBytesSafe( const char *input, const unsigned int inputLength, const unsigned int maxBytesToWrite ) { if (input==0 || inputLength==0) { WriteCompressed((unsigned int)0); return; } WriteCompressed(inputLength); WriteAlignedBytes((const unsigned char*) input, inputLength < maxBytesToWrite ? inputLength : maxBytesToWrite); } // Read bits, starting at the next aligned bits. Note that the modulus 8 starting offset of the // sequence must be the same as was used with WriteBits. This will be a problem with packet coalescence // unless you byte align the coalesced packets. bool BitStream::ReadAlignedBytes( unsigned char* output, const unsigned int numberOfBytesToRead ) { #ifdef _DEBUG assert( numberOfBytesToRead > 0 ); #endif if ( numberOfBytesToRead <= 0 ) return false; // Byte align AlignReadToByteBoundary(); if ( readOffset + ( numberOfBytesToRead << 3 ) > numberOfBitsUsed ) return false; // Write the data memcpy( output, data + ( readOffset >> 3 ), (size_t) numberOfBytesToRead ); readOffset += numberOfBytesToRead << 3; return true; } bool BitStream::ReadAlignedBytesSafe( char *input, int &inputLength, const int maxBytesToRead ) { return ReadAlignedBytesSafe(input,(unsigned int&) inputLength,(unsigned int)maxBytesToRead); } bool BitStream::ReadAlignedBytesSafe( char *input, unsigned int &inputLength, const unsigned int maxBytesToRead ) { if (ReadCompressed(inputLength)==false) return false; if (inputLength > maxBytesToRead) inputLength=maxBytesToRead; if (inputLength==0) return true; return ReadAlignedBytes((unsigned char*) input, inputLength); } bool BitStream::ReadAlignedBytesSafeAlloc( char **input, int &inputLength, const unsigned int maxBytesToRead ) { return ReadAlignedBytesSafeAlloc(input,(unsigned int&) inputLength, maxBytesToRead); } bool BitStream::ReadAlignedBytesSafeAlloc( char **input, unsigned int &inputLength, const unsigned int maxBytesToRead ) { free(*input); *input=0; if (ReadCompressed(inputLength)==false) return false; if (inputLength > maxBytesToRead) inputLength=maxBytesToRead; if (inputLength==0) return true; *input = (char*) malloc( (size_t) inputLength ); return ReadAlignedBytes((unsigned char*) *input, inputLength); } // Align the next write and/or read to a byte boundary. This can be used to 'waste' bits to byte align for efficiency reasons void BitStream::AlignWriteToByteBoundary( void ) { if ( numberOfBitsUsed ) numberOfBitsUsed += 8 - ( (( numberOfBitsUsed - 1 ) & 7) + 1 ); } // Align the next write and/or read to a byte boundary. This can be used to 'waste' bits to byte align for efficiency reasons void BitStream::AlignReadToByteBoundary( void ) { if ( readOffset ) readOffset += 8 - ( (( readOffset - 1 ) & 7 ) + 1 ); } // Write numberToWrite bits from the input source void BitStream::WriteBits( const unsigned char* input, uint32 numberOfBitsToWrite, const bool rightAlignedBits ) { // if (numberOfBitsToWrite<=0) // return; AddBitsAndReallocate( numberOfBitsToWrite ); unsigned char dataByte; const uint32 numberOfBitsUsedMod8 = numberOfBitsUsed & 7; const unsigned char* inputPtr=input; // Faster to put the while at the top surprisingly enough while ( numberOfBitsToWrite > 0 ) //do { dataByte = *( inputPtr++ ); if ( numberOfBitsToWrite < 8 && rightAlignedBits ) // rightAlignedBits means in the case of a partial byte, the bits are aligned from the right (bit 0) rather than the left (as in the normal internal representation) dataByte <<= 8 - numberOfBitsToWrite; // shift left to get the bits on the left, as in our internal representation // Writing to a new byte each time if ( numberOfBitsUsedMod8 == 0 ) * ( data + ( numberOfBitsUsed >> 3 ) ) = dataByte; else { // Copy over the new data. *( data + ( numberOfBitsUsed >> 3 ) ) |= dataByte >> ( numberOfBitsUsedMod8 ); // First half if ( 8 - ( numberOfBitsUsedMod8 ) < 8 && 8 - ( numberOfBitsUsedMod8 ) < numberOfBitsToWrite ) // If we didn't write it all out in the first half (8 - (numberOfBitsUsed%8) is the number we wrote in the first half) { *( data + ( numberOfBitsUsed >> 3 ) + 1 ) = (unsigned char) ( dataByte << ( 8 - ( numberOfBitsUsedMod8 ) ) ); // Second half (overlaps byte boundary) } } if ( numberOfBitsToWrite >= 8 ) { numberOfBitsUsed += 8; numberOfBitsToWrite -= 8; } else { numberOfBitsUsed += numberOfBitsToWrite; numberOfBitsToWrite=0; } } // } while(numberOfBitsToWrite>0); } // Set the stream to some initial data. For internal use void BitStream::SetData( unsigned char *input ) { data=input; copyData=false; } // Assume the input source points to a native type, compress and write it void BitStream::WriteCompressed( const unsigned char* input, const unsigned int size, const bool unsignedData ) { uint32 currentByte = ( size >> 3 ) - 1; // PCs unsigned char byteMatch; if ( unsignedData ) { byteMatch = 0; } else { byteMatch = 0xFF; } // Write upper bytes with a single 1 // From high byte to low byte, if high byte is a byteMatch then write a 1 bit. Otherwise write a 0 bit and then write the remaining bytes while ( currentByte > 0 ) { if ( input[ currentByte ] == byteMatch ) // If high byte is byteMatch (0 of 0xff) then it would have the same value shifted { bool b = true; Write( b ); } else { // Write the remainder of the data after writing 0 bool b = false; Write( b ); WriteBits( input, ( currentByte + 1 ) << 3, true ); // currentByte--; return ; } currentByte--; } // If the upper half of the last byte is a 0 (positive) or 16 (negative) then write a 1 and the remaining 4 bits. Otherwise write a 0 and the 8 bites. if ( ( unsignedData && ( ( *( input + currentByte ) ) & 0xF0 ) == 0x00 ) || ( unsignedData == false && ( ( *( input + currentByte ) ) & 0xF0 ) == 0xF0 ) ) { bool b = true; Write( b ); WriteBits( input + currentByte, 4, true ); } else { bool b = false; Write( b ); WriteBits( input + currentByte, 8, true ); } } // Read numberOfBitsToRead bits to the output source // alignBitsToRight should be set to true to convert internal bitstream data to userdata // It should be false if you used WriteBits with rightAlignedBits false bool BitStream::ReadBits( unsigned char *output, uint32 numberOfBitsToRead, const bool alignBitsToRight ) { #ifdef _DEBUG // assert( numberOfBitsToRead > 0 ); #endif if (numberOfBitsToRead<=0) return false; if ( readOffset + numberOfBitsToRead > numberOfBitsUsed ) return false; uint32 readOffsetMod8; uint32 offset = 0; memset( output, 0, (size_t) BITS_TO_BYTES( numberOfBitsToRead ) ); readOffsetMod8 = readOffset & 7; while ( numberOfBitsToRead > 0 ) { *( output + offset ) |= *( data + ( readOffset >> 3 ) ) << ( readOffsetMod8 ); // First half if ( readOffsetMod8 > 0 && numberOfBitsToRead > 8 - ( readOffsetMod8 ) ) // If we have a second half, we didn't read enough bytes in the first half *( output + offset ) |= *( data + ( readOffset >> 3 ) + 1 ) >> ( 8 - ( readOffsetMod8 ) ); // Second half (overlaps byte boundary) if (numberOfBitsToRead>=8) { numberOfBitsToRead -= 8; readOffset += 8; offset++; } else { int neg = (int) numberOfBitsToRead - 8; if ( neg < 0 ) // Reading a partial byte for the last byte, shift right so the data is aligned on the right { if ( alignBitsToRight ) * ( output + offset ) >>= -neg; readOffset += 8 + neg; } else readOffset += 8; offset++; numberOfBitsToRead=0; } } return true; } // Assume the input source points to a compressed native type. Decompress and read it bool BitStream::ReadCompressed( unsigned char* output, const unsigned int size, const bool unsignedData ) { unsigned int currentByte = ( size >> 3 ) - 1; unsigned char byteMatch, halfByteMatch; if ( unsignedData ) { byteMatch = 0; halfByteMatch = 0; } else { byteMatch = 0xFF; halfByteMatch = 0xF0; } // Upper bytes are specified with a single 1 if they match byteMatch // From high byte to low byte, if high byte is a byteMatch then write a 1 bit. Otherwise write a 0 bit and then write the remaining bytes while ( currentByte > 0 ) { // If we read a 1 then the data is byteMatch. bool b; if ( Read( b ) == false ) return false; if ( b ) // Check that bit { output[ currentByte ] = byteMatch; currentByte--; } else { // Read the rest of the bytes if ( ReadBits( output, ( currentByte + 1 ) << 3 ) == false ) return false; return true; } } // All but the first bytes are byteMatch. If the upper half of the last byte is a 0 (positive) or 16 (negative) then what we read will be a 1 and the remaining 4 bits. // Otherwise we read a 0 and the 8 bytes //assert(readOffset+1 <=numberOfBitsUsed); // If this assert is hit the stream wasn't long enough to read from if ( readOffset + 1 > numberOfBitsUsed ) return false; bool b; if ( Read( b ) == false ) return false; if ( b ) // Check that bit { if ( ReadBits( output + currentByte, 4 ) == false ) return false; output[ currentByte ] |= halfByteMatch; // We have to set the high 4 bits since these are set to 0 by ReadBits } else { if ( ReadBits( output + currentByte, 8 ) == false ) return false; } return true; } // Reallocates (if necessary) in preparation of writing numberOfBitsToWrite void BitStream::AddBitsAndReallocate( const uint32 numberOfBitsToWrite ) { if (numberOfBitsToWrite <= 0) return; uint32 newNumberOfBitsAllocated = numberOfBitsToWrite + numberOfBitsUsed; if ( numberOfBitsToWrite + numberOfBitsUsed > 0 && ( ( numberOfBitsAllocated - 1 ) >> 3 ) < ( ( newNumberOfBitsAllocated - 1 ) >> 3 ) ) // If we need to allocate 1 or more new bytes { #ifdef _DEBUG // If this assert hits then we need to specify true for the third parameter in the constructor // It needs to reallocate to hold all the data and can't do it unless we allocated to begin with // Often hits if you call Write or Serialize on a read-only bitstream assert( copyData == true ); #endif // Less memory efficient but saves on news and deletes /// Cap to 1 meg buffer to save on huge allocations newNumberOfBitsAllocated = ( numberOfBitsToWrite + numberOfBitsUsed ) * 2; if (newNumberOfBitsAllocated - ( numberOfBitsToWrite + numberOfBitsUsed ) > 1048576 ) newNumberOfBitsAllocated = numberOfBitsToWrite + numberOfBitsUsed + 1048576; // uint32 newByteOffset = BITS_TO_BYTES( numberOfBitsAllocated ); // Use realloc and free so we are more efficient than delete and new for resizing uint32 amountToAllocate = BITS_TO_BYTES( newNumberOfBitsAllocated ); if (data==(unsigned char*)stackData) { if (amountToAllocate > BITSTREAM_STACK_ALLOCATION_SIZE) { data = ( unsigned char* ) malloc( (size_t) amountToAllocate ); // need to copy the stack data over to our new memory area too memcpy ((void *)data, (void *)stackData, (size_t) BITS_TO_BYTES( numberOfBitsAllocated )); } } else { data = ( unsigned char* ) realloc( data, (size_t) amountToAllocate ); } #ifdef _DEBUG assert( data ); // Make sure realloc succeeded #endif // memset(data+newByteOffset, 0, ((newNumberOfBitsAllocated-1)>>3) - ((numberOfBitsAllocated-1)>>3)); // Set the new data block to 0 } if ( newNumberOfBitsAllocated > numberOfBitsAllocated ) numberOfBitsAllocated = newNumberOfBitsAllocated; } uint32 BitStream::GetNumberOfBitsAllocated(void) const { return numberOfBitsAllocated; } // Should hit if reads didn't match writes void BitStream::AssertStreamEmpty( void ) { assert( readOffset == numberOfBitsUsed ); } void BitStream::PrintBits( char *out ) const { if ( numberOfBitsUsed <= 0 ) { strcpy(out, "No bits\n" ); return; } unsigned int strIndex=0; for ( uint32 counter = 0; counter < BITS_TO_BYTES( numberOfBitsUsed ); counter++ ) { uint32 stop; if ( counter == ( numberOfBitsUsed - 1 ) >> 3 ) stop = 8 - ( ( ( numberOfBitsUsed - 1 ) & 7 ) + 1 ); else stop = 0; for ( uint32 counter2 = 7; counter2 >= stop; counter2-- ) { if ( ( data[ counter ] >> counter2 ) & 1 ) out[strIndex++]='1'; else out[strIndex++]='0'; if (counter2==0) break; } out[strIndex++]=' '; } out[strIndex++]='\n'; out[strIndex++]=0; } void BitStream::PrintBits( void ) const { char out[2048]; PrintBits(out); printf(out); } void BitStream::PrintHex( char *out ) const { uint32 i; for ( i=0; i < GetNumberOfBytesUsed(); i++) { sprintf(out+i*3, "%02x ", data[i]); } } void BitStream::PrintHex( void ) const { char out[2048]; PrintHex(out); printf(out); } // Exposes the data for you to look at, like PrintBits does. // Data will point to the stream. Returns the length in bits of the stream. uint32 BitStream::CopyData( unsigned char** _data ) const { #ifdef _DEBUG assert( numberOfBitsUsed > 0 ); #endif *_data = (unsigned char*) malloc( (size_t) BITS_TO_BYTES( numberOfBitsUsed ) ); memcpy( *_data, data, sizeof(unsigned char) * (size_t) ( BITS_TO_BYTES( numberOfBitsUsed ) ) ); return numberOfBitsUsed; } // Ignore data we don't intend to read void BitStream::IgnoreBits( const uint32 numberOfBits ) { readOffset += numberOfBits; } void BitStream::IgnoreBytes( const unsigned int numberOfBytes ) { IgnoreBits(BYTES_TO_BITS(numberOfBytes)); } // Move the write pointer to a position on the array. Dangerous if you don't know what you are doing! // Doesn't work with non-aligned data! void BitStream::SetWriteOffset( const uint32 offset ) { numberOfBitsUsed = offset; } /* uint32 BitStream::GetWriteOffset( void ) const { return numberOfBitsUsed; } // Returns the length in bits of the stream uint32 BitStream::GetNumberOfBitsUsed( void ) const { return GetWriteOffset(); } // Returns the length in bytes of the stream uint32 BitStream::GetNumberOfBytesUsed( void ) const { return BITS_TO_BYTES( numberOfBitsUsed ); } // Returns the number of bits into the stream that we have read uint32 BitStream::GetReadOffset( void ) const { return readOffset; } // Sets the read bit index void BitStream::SetReadOffset( const uint32 newReadOffset ) { readOffset=newReadOffset; } // Returns the number of bits left in the stream that haven't been read uint32 BitStream::GetNumberOfUnreadBits( void ) const { return numberOfBitsUsed - readOffset; } // Exposes the internal data unsigned char* BitStream::GetData( void ) const { return data; } */ // If we used the constructor version with copy data off, this makes sure it is set to on and the data pointed to is copied. void BitStream::AssertCopyData( void ) { if ( copyData == false ) { copyData = true; if ( numberOfBitsAllocated > 0 ) { unsigned char * newdata = ( unsigned char* ) malloc( (size_t) BITS_TO_BYTES( numberOfBitsAllocated ) ); #ifdef _DEBUG assert( data ); #endif memcpy( newdata, data, (size_t) BITS_TO_BYTES( numberOfBitsAllocated ) ); data = newdata; } else data = 0; } } void BitStream::ReverseBytes(unsigned char *input, unsigned char *output, const unsigned int length) { for (uint32 i=0; i < length; i++) output[i]=input[length-i-1]; } void BitStream::ReverseBytesInPlace(unsigned char *data,const unsigned int length) { unsigned char temp; uint32 i; for (i=0; i < (length>>1); i++) { temp = data[i]; data[i]=data[length-i-1]; data[length-i-1]=temp; } } bool BitStream::DoEndianSwap(void) { return false; } bool BitStream::IsBigEndian(void) { return IsNetworkOrder(); } bool BitStream::IsNetworkOrder(void) { static bool isNetworkOrder=(htonl(12345) == 12345); return isNetworkOrder; } #ifdef _MSC_VER #pragma warning( pop ) #endif