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//========================================================================
//
// JpegWriter.cc
//
// This file is licensed under the GPLv2 or later
//
// Copyright (C) 2009 Stefan Thomas <thomas@eload24.com>
// Copyright (C) 2010 Adrian Johnson <ajohnson@redneon.com>
// Copyright (C) 2010 Harry Roberts <harry.roberts@midnight-labs.org>
//
//========================================================================
#include "JpegWriter.h"
#ifdef ENABLE_LIBJPEG
#include "poppler/Error.h"
void outputMessage(j_common_ptr cinfo)
{
char buffer[JMSG_LENGTH_MAX];
// Create the message
(*cinfo->err->format_message) (cinfo, buffer);
// Send it to poppler's error handler
error(-1, "%s", buffer);
}
JpegWriter::JpegWriter(int q, bool p)
: progressive(p), quality(q)
{
}
JpegWriter::JpegWriter()
: progressive(false), quality(-1)
{
}
JpegWriter::~JpegWriter()
{
// cleanup
jpeg_destroy_compress(&cinfo);
}
bool JpegWriter::init(FILE *f, int width, int height, int hDPI, int vDPI)
{
// Setup error handler
cinfo.err = jpeg_std_error(&jerr);
jerr.output_message = &outputMessage;
// Initialize libjpeg
jpeg_create_compress(&cinfo);
// Set destination file
jpeg_stdio_dest(&cinfo, f);
// Set libjpeg configuration
cinfo.image_width = width;
cinfo.image_height = height;
cinfo.density_unit = 1; // dots per inch
cinfo.X_density = hDPI;
cinfo.Y_density = vDPI;
cinfo.input_components = 3; /* # of color components per pixel */
cinfo.in_color_space = JCS_RGB; /* colorspace of input image */
jpeg_set_defaults(&cinfo);
// Set quality
if( quality >= 0 && quality <= 100 ) {
jpeg_set_quality(&cinfo, quality, true);
}
// Use progressive mode
if( progressive) {
jpeg_simple_progression(&cinfo);
}
// Get ready for data
jpeg_start_compress(&cinfo, TRUE);
return true;
}
bool JpegWriter::writePointers(unsigned char **rowPointers, int rowCount)
{
// Write all rows to the file
jpeg_write_scanlines(&cinfo, rowPointers, rowCount);
return true;
}
bool JpegWriter::writeRow(unsigned char **row)
{
// Write the row to the file
jpeg_write_scanlines(&cinfo, row, 1);
return true;
}
bool JpegWriter::close()
{
jpeg_finish_compress(&cinfo);
return true;
}
#endif
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