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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, 2012 Adrian Johnson <ajohnson@redneon.com>
// Copyright (C) 2010 Harry Roberts <harry.roberts@midnight-labs.org>
// Copyright (C) 2011 Thomas Freitag <Thomas.Freitag@alfa.de>
//
//========================================================================
#include "JpegWriter.h"
#ifdef ENABLE_LIBJPEG
extern "C" {
#include <jpeglib.h>
}
#include "poppler/Error.h"
struct JpegWriterPrivate {
bool progressive;
int quality;
JpegWriter::Format format;
struct jpeg_compress_struct cinfo;
struct jpeg_error_mgr jerr;
};
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(errInternal, -1, "{0:s}", buffer);
}
JpegWriter::JpegWriter(int q, bool p, Format formatA)
{
priv = new JpegWriterPrivate;
priv->progressive = p;
priv->quality = q;
priv->format = formatA;
}
JpegWriter::JpegWriter(Format formatA)
{
priv = new JpegWriterPrivate;
priv->progressive = false;
priv->quality = -1;
priv->format = formatA;
}
JpegWriter::~JpegWriter()
{
// cleanup
jpeg_destroy_compress(&priv->cinfo);
delete priv;
}
bool JpegWriter::init(FILE *f, int width, int height, int hDPI, int vDPI)
{
// Setup error handler
priv->cinfo.err = jpeg_std_error(&priv->jerr);
priv->jerr.output_message = &outputMessage;
// Initialize libjpeg
jpeg_create_compress(&priv->cinfo);
// First set colorspace and call jpeg_set_defaults() since
// jpeg_set_defaults() sets default values for all fields in
// cinfo based on the colorspace.
switch (priv->format) {
case RGB:
priv->cinfo.in_color_space = JCS_RGB;
break;
case GRAY:
priv->cinfo.in_color_space = JCS_GRAYSCALE;
break;
case CMYK:
priv->cinfo.in_color_space = JCS_CMYK;
break;
default:
return false;
}
jpeg_set_defaults(&priv->cinfo);
// Set destination file
jpeg_stdio_dest(&priv->cinfo, f);
// Set libjpeg configuration
priv->cinfo.image_width = width;
priv->cinfo.image_height = height;
priv->cinfo.density_unit = 1; // dots per inch
priv->cinfo.X_density = hDPI;
priv->cinfo.Y_density = vDPI;
switch (priv->format) {
case GRAY:
priv->cinfo.input_components = 1;
break;
case RGB:
priv->cinfo.input_components = 3;
break;
case CMYK:
priv->cinfo.input_components = 4;
jpeg_set_colorspace(&priv->cinfo, JCS_YCCK);
priv->cinfo.write_JFIF_header = TRUE;
break;
default:
return false;
}
// Set quality
if (priv->quality >= 0 && priv->quality <= 100) {
jpeg_set_quality(&priv->cinfo, priv->quality, true);
}
// Use progressive mode
if (priv->progressive) {
jpeg_simple_progression(&priv->cinfo);
}
// Get ready for data
jpeg_start_compress(&priv->cinfo, TRUE);
return true;
}
bool JpegWriter::writePointers(unsigned char **rowPointers, int rowCount)
{
if (priv->format == CMYK) {
for (int y = 0; y < rowCount; y++) {
unsigned char *row = rowPointers[y];
for (unsigned int x = 0; x < priv->cinfo.image_width; x++) {
for (int n = 0; n < 4; n++) {
*row = 0xff - *row;
row++;
}
}
}
}
// Write all rows to the file
jpeg_write_scanlines(&priv->cinfo, rowPointers, rowCount);
return true;
}
bool JpegWriter::writeRow(unsigned char **rowPointer)
{
if (priv->format == CMYK) {
unsigned char *row = rowPointer[0];
for (unsigned int x = 0; x < priv->cinfo.image_width; x++) {
for (int n = 0; n < 4; n++) {
*row = 0xff - *row;
row++;
}
}
}
// Write the row to the file
jpeg_write_scanlines(&priv->cinfo, rowPointer, 1);
return true;
}
bool JpegWriter::close()
{
jpeg_finish_compress(&priv->cinfo);
return true;
}
bool JpegWriter::supportCMYK()
{
return priv->format == CMYK;
}
#endif
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