blkwtdata.cpp

jpeg 2000 压缩算法源代码 核心ebcot

7;
	m_nByteNums=0;
	m_BitBuffer=0;


}

BitToByteOutput::~BitToByteOutput()
{
	

}

BitToByteOutput::BitToByteOutput(ByteOutputBuffer *pOut)
{
	m_pOut=0;
	m_bDelFF=false;
	m_nBitPosition=7;
	m_nByteNums=0;
	m_BitBuffer=0;
	
	m_pOut=pOut;

}

void BitToByteOutput::Reset()
{
	m_bDelFF = false;
    m_nBitPosition = 7;
    m_BitBuffer = 0;
    m_nByteNums = 0;

}

void BitToByteOutput::WriteBit(int nBit)
{
	 m_BitBuffer |= (nBit&0x01)<<(m_nBitPosition--);
        if (m_nBitPosition<0) {
            if (m_BitBuffer != 0xFF) { // No bit-stuffing needed
                if (m_bDelFF) { // Output delayed 0xFF if any
                    m_pOut->Write(0xFF);
                    m_bDelFF = false;
                    m_nByteNums++;
                }
                // Output the bit buffer
                m_pOut->Write(m_BitBuffer);
                m_nByteNums++;
                m_nBitPosition = 7;
            }
            else { // We need to do bit stuffing on next byte
                m_bDelFF = true;
                m_nBitPosition = 6; // One less bit in next byte
            }
            m_BitBuffer = 0;
        }

}

void BitToByteOutput::WriteBits(int *pSymBuf, int nSymNums)
{
	int i;
    int bbuf,bpos;
    bbuf = m_BitBuffer;
    bpos = m_nBitPosition;

    // Write symbol by symbol to bit buffer
    for (i=0; i<nSymNums; i++) {
        bbuf |= (pSymBuf[i]&0x01)<<(bpos--);
        if (bpos<0) { // Bit buffer is full, write it
             if (bbuf != 0xFF) { // No bit-stuffing needed
                    if (m_bDelFF) { // Output delayed 0xFF if any
                        m_pOut->Write(0xFF);
                        m_bDelFF = false;
                        m_nByteNums++;
                    }
                    m_pOut->Write(bbuf);
                    m_nByteNums++;
                    m_nBitPosition = 7;
                }
                else { // We need to do bit stuffing on next byte
                    m_bDelFF = true;
                    m_nBitPosition = 6; // One less bit in next byte
                }
                bbuf = 0;
            }
        }
        m_BitBuffer = bbuf;
        m_nBitPosition = bpos;

}

void BitToByteOutput::Flush()
{
	if (m_bDelFF) { // There was a bit stuffing
            if (m_nBitPosition != 6) { // Bit buffer is not empty
                // Output delayed 0xFF
                m_pOut->Write(0xFF);
                m_bDelFF = false;
                m_nByteNums++;
                // Pad to byte boundary with an alternating sequence of 0's
                // and 1's.
                m_BitBuffer |= (PAD_SEQ >> (6-m_nBitPosition));
                // Output the bit buffer
                m_pOut->Write(m_BitBuffer);
                m_nByteNums++;
                m_nBitPosition = 7;
                m_BitBuffer = 0;
            }
        }
        else { // There was no bit stuffing
            if (m_nBitPosition != 7) { // Bit buffer is not empty
                // Pad to byte boundary with an alt