JOutputStream& JFileIOStream::operator<<(const JBlock &B) {
int numWrite;
int numBytes = B.size();
if (!numBytes) return *this;
if ((numWrite = _write_(hnd, B, numBytes)) < 0) {
throw new JIOException("file write error");
} else if (numWrite != numBytes) {
B.setSize(numWrite);
throw new JIOException("file write not complete");
}
return *this;
}
//-------------------------------------------------------------------------------
void JpegEncoder::_write_jpeg_header(FILE* fp)
{
//SOI
_write_word_(0xFFD8, fp); // marker = 0xFFD8
//APPO
_write_word_(0xFFE0,fp); // marker = 0xFFE0
_write_word_(16, fp); // length = 16 for usual JPEG, no thumbnail
_write_("JFIF", 5, fp); // 'JFIF\0'
_write_byte_(1, fp); // version_hi
_write_byte_(1, fp); // version_low
_write_byte_(0, fp); // xyunits = 0 no units, normal density
_write_word_(1, fp); // xdensity
_write_word_(1, fp); // ydensity
_write_byte_(0, fp); // thumbWidth
_write_byte_(0, fp); // thumbHeight
//DQT
_write_word_(0xFFDB, fp); //marker = 0xFFDB
_write_word_(132, fp); //size=132
_write_byte_(0, fp); //QTYinfo== 0: bit 0..3: number of QT = 0 (table for Y)
// bit 4..7: precision of QT
// bit 8 : 0
_write_(m_YTable, 64, fp); //YTable
_write_byte_(1, fp); //QTCbinfo = 1 (quantization table for Cb,Cr)
_write_(m_CbCrTable, 64, fp); //CbCrTable
//SOFO
_write_word_(0xFFC0, fp); //marker = 0xFFC0
_write_word_(17, fp); //length = 17 for a truecolor YCbCr JPG
_write_byte_(8, fp); //precision = 8: 8 bits/sample
_write_word_(m_height&0xFFFF, fp); //height
_write_word_(m_width&0xFFFF, fp); //width
_write_byte_(3, fp); //nrofcomponents = 3: We encode a truecolor JPG
_write_byte_(1, fp); //IdY = 1
_write_byte_(0x11, fp); //HVY sampling factors for Y (bit 0-3 vert., 4-7 hor.)(SubSamp 1x1)
_write_byte_(0, fp); //QTY Quantization Table number for Y = 0
_write_byte_(2, fp); //IdCb = 2
_write_byte_(0x11, fp); //HVCb = 0x11(SubSamp 1x1)
_write_byte_(1, fp); //QTCb = 1
_write_byte_(3, fp); //IdCr = 3
_write_byte_(0x11, fp); //HVCr = 0x11 (SubSamp 1x1)
_write_byte_(1, fp); //QTCr Normally equal to QTCb = 1
//DHT
_write_word_(0xFFC4, fp); //marker = 0xFFC4
_write_word_(0x01A2, fp); //length = 0x01A2
_write_byte_(0, fp); //HTYDCinfo bit 0..3 : number of HT (0..3), for Y =0
// bit 4 : type of HT, 0 = DC table,1 = AC table
// bit 5..7 : not used, must be 0
_write_(Standard_DC_Luminance_NRCodes, sizeof(Standard_DC_Luminance_NRCodes), fp); //DC_L_NRC
_write_(Standard_DC_Luminance_Values, sizeof(Standard_DC_Luminance_Values), fp); //DC_L_VALUE
_write_byte_(0x10, fp); //HTYACinfo
_write_(Standard_AC_Luminance_NRCodes, sizeof(Standard_AC_Luminance_NRCodes), fp);
_write_(Standard_AC_Luminance_Values, sizeof(Standard_AC_Luminance_Values), fp); //we'll use the standard Huffman tables
_write_byte_(0x01, fp); //HTCbDCinfo
_write_(Standard_DC_Chromiance_NRCodes, sizeof(Standard_DC_Chromiance_NRCodes), fp);
_write_(Standard_DC_Chromiance_Values, sizeof(Standard_DC_Chromiance_Values), fp);
_write_byte_(0x11, fp); //HTCbACinfo
_write_(Standard_AC_Chromiance_NRCodes, sizeof(Standard_AC_Chromiance_NRCodes), fp);
_write_(Standard_AC_Chromiance_Values, sizeof(Standard_AC_Chromiance_Values), fp);
//SOS
_write_word_(0xFFDA, fp); //marker = 0xFFC4
_write_word_(12, fp); //length = 12
_write_byte_(3, fp); //nrofcomponents, Should be 3: truecolor JPG
_write_byte_(1, fp); //Idy=1
_write_byte_(0, fp); //HTY bits 0..3: AC table (0..3)
// bits 4..7: DC table (0..3)
_write_byte_(2, fp); //IdCb
_write_byte_(0x11, fp); //HTCb
_write_byte_(3, fp); //IdCr
_write_byte_(0x11, fp); //HTCr
_write_byte_(0, fp); //Ss not interesting, they should be 0,63,0
_write_byte_(0x3F, fp); //Se
_write_byte_(0, fp); //Bf
}
//-------------------------------------------------------------------------------
void JpegEncoder::_write_word_(unsigned short value, FILE* fp)
{
unsigned short _value = ((value>>8)&0xFF) | ((value&0xFF)<<8);
_write_(&_value, 2, fp);
}
//-------------------------------------------------------------------------------
void JpegEncoder::_write_byte_(unsigned char value, FILE* fp)
{
_write_(&value, 1, fp);
}
