//------------------------------------------------------------------------
// JpegEncoder::InitCompressor
//------------------------------------------------------------------------
void JpegEncoder::InitCompressor(MemBufPtr ptrmbSrc, struct jpeg_compress_struct *pcinfo)
{
int iWidth, iHeight;
try
{
ptrmbSrc->GetIntegerMetadata("width", &iWidth);
ptrmbSrc->GetIntegerMetadata("height", &iHeight);
}
catch( NoDataException e )
{
// Transform exception into a jpeg exception
throw JpegEncoder::Exception(PSZ(e.Error()), PSZ(e.Reason()), "JpegEncoder::InitCompressor");
}
if( iWidth < 1 ||iWidth > JPEG_MAX_DIMENSION )
throw JpegEncoder::Exception("BAD_PARAMETER", "Wrongs image dimensions. Must be in [1, 65000]", "JpegEncoder::Encode");
// create context
jpeg_create_compress(pcinfo);
// Put cinfo values
pcinfo->image_width = iWidth;
pcinfo->image_height = iHeight;
pcinfo->input_components = 1; // grayscale image
pcinfo->in_color_space = JCS_GRAYSCALE;
// Set compression parameters to default values
jpeg_set_defaults(pcinfo);
// Set quality to max
jpeg_set_quality(pcinfo, 100, TRUE);
}
//------------------------------------------------------------------------
// BmpEncoder::EncodeGrayScaleToMemBuf
//------------------------------------------------------------------------
void BmpEncoder::EncodeGrayScaleToMemBuf(MemBufPtr ptrmbSrc, MemBufPtr ptrmbDst)
{
int iWidth, iHeight;
try
{
ptrmbSrc->GetIntegerMetadata("width", &iWidth);
ptrmbSrc->GetIntegerMetadata("height", &iHeight);
}
catch( NoDataException e )
{
// Transform exception into a jpeg exception
throw BmpEncoder::Exception(PSZ(e.Error()), PSZ(e.Reason()), "BmpEncoder::EncodeGrayScaleToMemBuf");
}
if( iWidth < 1 || iWidth > BMP_MAX_DIMENSION )
throw Exception("BAD_PARAMETER", "Wrongs image dimensions. Must be in [1, 65000]", "BmpEncoder::EncodeGrayScaleToMemBuf");
int iBytePaddingPerRow = 0;
EncodeHeader(ptrmbDst, 8, iWidth, iHeight, &iBytePaddingPerRow);
// Image data
for( int y = 0; y < iHeight; y++ )
{
ptrmbDst->PutBloc((uint8 *)(ptrmbSrc->Buf()) + (iHeight - y - 1) * iWidth, iWidth);
for( int i = 0; i < iBytePaddingPerRow; i++ )
(*ptrmbDst) << (uint8)0;
}
}
//------------------------------------------------------------------------
// JpegEncoder::Compress
//------------------------------------------------------------------------
void JpegEncoder::Compress(MemBufPtr ptrmbSrc, struct jpeg_compress_struct *pcinfo)
{
// Start compressor
jpeg_start_compress(pcinfo, TRUE);
JSAMPROW *row_pointer = new JSAMPROW[pcinfo->image_height];
for( uint ui = 0; ui < pcinfo->image_height; ui++ )
row_pointer[ui] = (unsigned char *)(ptrmbSrc->Buf() + ui * pcinfo->image_width);
// Write all rows in one single pass
jpeg_write_scanlines(pcinfo, row_pointer, pcinfo->image_height);
// Terminate encoding process
jpeg_finish_compress(pcinfo);
jpeg_destroy_compress(pcinfo);
}
