root/modules/imgcodecs/src/bitstrm.cpp

DEFINITIONS

1. bsIsBigEndian
2. isOpened
3. allocate
4. readBlock
5. open
6. open
7. close
8. release
9. setPos
10. getPos
11. skip
12. getByte
13. getBytes
14. getWord
15. getDWord
16. getWord
17. getDWord
18. isOpened
19. allocate
20. writeBlock
21. open
22. open
23. close
24. release
25. getPos
26. putByte
27. putBytes
28. putWord
29. putDWord
30. putWord
31. putDWord

/*M///////////////////////////////////////////////////////////////////////////////////////
//
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//
//  By downloading, copying, installing or using the software you agree to this license.
//  If you do not agree to this license, do not download, install,
//  copy or use the software.
//
//
//                           License Agreement
//                For Open Source Computer Vision Library
//
// Copyright (C) 2000-2008, Intel Corporation, all rights reserved.
// Copyright (C) 2009, Willow Garage Inc., all rights reserved.
// Third party copyrights are property of their respective owners.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
//
//   * Redistribution's of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
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//     and/or other materials provided with the distribution.
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//   * The name of the copyright holders may not be used to endorse or promote products
//     derived from this software without specific prior written permission.
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// This software is provided by the copyright holders and contributors "as is" and
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// indirect, incidental, special, exemplary, or consequential damages
// (including, but not limited to, procurement of substitute goods or services;
// loss of use, data, or profits; or business interruption) however caused
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#include "precomp.hpp"
#include "bitstrm.hpp"

namespace cv
{

const int BS_DEF_BLOCK_SIZE = 1<<15;

bool  bsIsBigEndian( void )
{
    return (((const int*)"\0\x1\x2\x3\x4\x5\x6\x7")[0] & 255) != 0;
}

/////////////////////////  RBaseStream ////////////////////////////

bool  RBaseStream::isOpened()
{
    return m_is_opened;
}

void  RBaseStream::allocate()
{
    if( !m_allocated )
    {
        m_start = new uchar[m_block_size];
        m_end = m_start + m_block_size;
        m_current = m_end;
        m_allocated = true;
    }
}


RBaseStream::RBaseStream()
{
    m_start = m_end = m_current = 0;
    m_file = 0;
    m_block_size = BS_DEF_BLOCK_SIZE;
    m_is_opened = false;
    m_allocated = false;
}


RBaseStream::~RBaseStream()
{
    close();    // Close files
    release();  // free  buffers
}


void  RBaseStream::readBlock()
{
    setPos( getPos() ); // normalize position

    if( m_file == 0 )
    {
        if( m_block_pos == 0 && m_current < m_end )
            return;
        throw RBS_THROW_EOS;
    }

    fseek( m_file, m_block_pos, SEEK_SET );
    size_t readed = fread( m_start, 1, m_block_size, m_file );
    m_end = m_start + readed;
    m_current = m_start;

    if( readed == 0 || m_current >= m_end )
        throw RBS_THROW_EOS;
}


bool  RBaseStream::open( const String& filename )
{
    close();
    allocate();

    m_file = fopen( filename.c_str(), "rb" );
    if( m_file )
    {
        m_is_opened = true;
        setPos(0);
        readBlock();
    }
    return m_file != 0;
}

bool  RBaseStream::open( const Mat& buf )
{
    close();
    if( buf.empty() )
        return false;
    CV_Assert(buf.isContinuous());
    m_start = buf.data;
    m_end = m_start + buf.cols*buf.rows*buf.elemSize();
    m_allocated = false;
    m_is_opened = true;
    setPos(0);

    return true;
}

void  RBaseStream::close()
{
    if( m_file )
    {
        fclose( m_file );
        m_file = 0;
    }
    m_is_opened = false;
    if( !m_allocated )
        m_start = m_end = m_current = 0;
}


void  RBaseStream::release()
{
    if( m_allocated )
        delete[] m_start;
    m_start = m_end = m_current = 0;
    m_allocated = false;
}


void  RBaseStream::setPos( int pos )
{
    assert( isOpened() && pos >= 0 );

    if( !m_file )
    {
        m_current = m_start + pos;
        m_block_pos = 0;
        return;
    }

    int offset = pos % m_block_size;
    m_block_pos = pos - offset;
    m_current = m_start + offset;
}


int  RBaseStream::getPos()
{
    assert( isOpened() );
    return m_block_pos + (int)(m_current - m_start);
}

void  RBaseStream::skip( int bytes )
{
    assert( bytes >= 0 );
    m_current += bytes;
}

/////////////////////////  RLByteStream ////////////////////////////

RLByteStream::~RLByteStream()
{
}

int  RLByteStream::getByte()
{
    uchar *current = m_current;
    int   val;

    if( current >= m_end )
    {
        readBlock();
        current = m_current;
    }

    val = *((uchar*)current);
    m_current = current + 1;
    return val;
}


int RLByteStream::getBytes( void* buffer, int count )
{
    uchar*  data = (uchar*)buffer;
    int readed = 0;
    assert( count >= 0 );

    while( count > 0 )
    {
        int l;

        for(;;)
        {
            l = (int)(m_end - m_current);
            if( l > count ) l = count;
            if( l > 0 ) break;
            readBlock();
        }
        memcpy( data, m_current, l );
        m_current += l;
        data += l;
        count -= l;
        readed += l;
    }
    return readed;
}


////////////  RLByteStream & RMByteStream <Get[d]word>s ////////////////

RMByteStream::~RMByteStream()
{
}


int  RLByteStream::getWord()
{
    uchar *current = m_current;
    int   val;

    if( current+1 < m_end )
    {
        val = current[0] + (current[1] << 8);
        m_current = current + 2;
    }
    else
    {
        val = getByte();
        val|= getByte() << 8;
    }
    return val;
}


int  RLByteStream::getDWord()
{
    uchar *current = m_current;
    int   val;

    if( current+3 < m_end )
    {
        val = current[0] + (current[1] << 8) +
              (current[2] << 16) + (current[3] << 24);
        m_current = current + 4;
    }
    else
    {
        val = getByte();
        val |= getByte() << 8;
        val |= getByte() << 16;
        val |= getByte() << 24;
    }
    return val;
}


int  RMByteStream::getWord()
{
    uchar *current = m_current;
    int   val;

    if( current+1 < m_end )
    {
        val = (current[0] << 8) + current[1];
        m_current = current + 2;
    }
    else
    {
        val = getByte() << 8;
        val|= getByte();
    }
    return val;
}


int  RMByteStream::getDWord()
{
    uchar *current = m_current;
    int   val;

    if( current+3 < m_end )
    {
        val = (current[0] << 24) + (current[1] << 16) +
              (current[2] << 8) + current[3];
        m_current = current + 4;
    }
    else
    {
        val = getByte() << 24;
        val |= getByte() << 16;
        val |= getByte() << 8;
        val |= getByte();
    }
    return val;
}

/////////////////////////// WBaseStream /////////////////////////////////

// WBaseStream - base class for output streams
WBaseStream::WBaseStream()
{
    m_start = m_end = m_current = 0;
    m_file = 0;
    m_block_size = BS_DEF_BLOCK_SIZE;
    m_is_opened = false;
    m_buf = 0;
}


WBaseStream::~WBaseStream()
{
    close();
    release();
}


bool  WBaseStream::isOpened()
{
    return m_is_opened;
}


void  WBaseStream::allocate()
{
    if( !m_start )
        m_start = new uchar[m_block_size];

    m_end = m_start + m_block_size;
    m_current = m_start;
}


void  WBaseStream::writeBlock()
{
    int size = (int)(m_current - m_start);

    assert( isOpened() );
    if( size == 0 )
        return;

    if( m_buf )
    {
        size_t sz = m_buf->size();
        m_buf->resize( sz + size );
        memcpy( &(*m_buf)[sz], m_start, size );
    }
    else
    {
        fwrite( m_start, 1, size, m_file );
    }
    m_current = m_start;
    m_block_pos += size;
}


bool  WBaseStream::open( const String& filename )
{
    close();
    allocate();

    m_file = fopen( filename.c_str(), "wb" );
    if( m_file )
    {
        m_is_opened = true;
        m_block_pos = 0;
        m_current = m_start;
    }
    return m_file != 0;
}

bool  WBaseStream::open( std::vector<uchar>& buf )
{
    close();
    allocate();

    m_buf = &buf;
    m_is_opened = true;
    m_block_pos = 0;
    m_current = m_start;

    return true;
}

void  WBaseStream::close()
{
    if( m_is_opened )
        writeBlock();
    if( m_file )
    {
        fclose( m_file );
        m_file = 0;
    }
    m_buf = 0;
    m_is_opened = false;
}


void  WBaseStream::release()
{
    if( m_start )
        delete[] m_start;
    m_start = m_end = m_current = 0;
}


int  WBaseStream::getPos()
{
    assert( isOpened() );
    return m_block_pos + (int)(m_current - m_start);
}


///////////////////////////// WLByteStream ///////////////////////////////////

WLByteStream::~WLByteStream()
{
}

void WLByteStream::putByte( int val )
{
    *m_current++ = (uchar)val;
    if( m_current >= m_end )
        writeBlock();
}


void WLByteStream::putBytes( const void* buffer, int count )
{
    uchar* data = (uchar*)buffer;

    assert( data && m_current && count >= 0 );

    while( count )
    {
        int l = (int)(m_end - m_current);

        if( l > count )
            l = count;

        if( l > 0 )
        {
            memcpy( m_current, data, l );
            m_current += l;
            data += l;
            count -= l;
        }
        if( m_current == m_end )
            writeBlock();
    }
}


void WLByteStream::putWord( int val )
{
    uchar *current = m_current;

    if( current+1 < m_end )
    {
        current[0] = (uchar)val;
        current[1] = (uchar)(val >> 8);
        m_current = current + 2;
        if( m_current == m_end )
            writeBlock();
    }
    else
    {
        putByte(val);
        putByte(val >> 8);
    }
}


void WLByteStream::putDWord( int val )
{
    uchar *current = m_current;

    if( current+3 < m_end )
    {
        current[0] = (uchar)val;
        current[1] = (uchar)(val >> 8);
        current[2] = (uchar)(val >> 16);
        current[3] = (uchar)(val >> 24);
        m_current = current + 4;
        if( m_current == m_end )
            writeBlock();
    }
    else
    {
        putByte(val);
        putByte(val >> 8);
        putByte(val >> 16);
        putByte(val >> 24);
    }
}


///////////////////////////// WMByteStream ///////////////////////////////////

WMByteStream::~WMByteStream()
{
}


void WMByteStream::putWord( int val )
{
    uchar *current = m_current;

    if( current+1 < m_end )
    {
        current[0] = (uchar)(val >> 8);
        current[1] = (uchar)val;
        m_current = current + 2;
        if( m_current == m_end )
            writeBlock();
    }
    else
    {
        putByte(val >> 8);
        putByte(val);
    }
}


void WMByteStream::putDWord( int val )
{
    uchar *current = m_current;

    if( current+3 < m_end )
    {
        current[0] = (uchar)(val >> 24);
        current[1] = (uchar)(val >> 16);
        current[2] = (uchar)(val >> 8);
        current[3] = (uchar)val;
        m_current = current + 4;
        if( m_current == m_end )
            writeBlock();
    }
    else
    {
        putByte(val >> 24);
        putByte(val >> 16);
        putByte(val >> 8);
        putByte(val);
    }
}

}