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/*
render/jpgfile.cc
This file is part of the Osirion project and is distributed under
the terms of the GNU General Public License version 2
*/
/*
Notes:
http://www.zarb.org/~gc/html/libpng.html
*/
#include <cstring>
#include <iostream>
#include "filesystem/filesystem.h"
#include "render/jpgfile.h"
#include "sys/sys.h"
extern "C" {
#include "jpeglib.h"
}
namespace render {
Image *JPG::load(const char *filename)
{
struct jpeg_decompress_struct jpeg_decompression_info;
struct jpeg_error_mgr jerr;
int row_stride = 0;
Image *image = 0;
if (!filename)
return 0;
filesystem::File *jpg_file = filesystem::open(filename);
if (!jpg_file) {
//con_warn << "Could not open " << filename << std::endl;
return 0;
}
// initialize decompression structures
jpeg_decompression_info.err = jpeg_std_error(&jerr);
jpeg_create_decompress(&jpeg_decompression_info);
jpeg_stdio_src(&jpeg_decompression_info, jpg_file->handle());
// read JPEG header
jpeg_read_header(&jpeg_decompression_info, TRUE);
jpeg_start_decompress(&jpeg_decompression_info);
row_stride = jpeg_decompression_info.output_width * jpeg_decompression_info.output_components;
image = new Image(jpeg_decompression_info.output_width,
jpeg_decompression_info.output_height,
jpeg_decompression_info.output_components);
// read pixel data
JSAMPLE *row_pointer;
while (jpeg_decompression_info.output_scanline < jpeg_decompression_info.output_height) {
row_pointer = (*image)[jpeg_decompression_info.output_scanline*row_stride];
jpeg_read_scanlines(&jpeg_decompression_info, &row_pointer, 1);
}
jpeg_finish_decompress(&jpeg_decompression_info);
// destroy decompression structures
jpeg_destroy_decompress(&jpeg_decompression_info);
filesystem::close(jpg_file);
con_debug << " " << filename << " " << image->width() << "x" << image->height() << "x" << image->bpp() << "bpp" << std::endl;
return image;
}
void JPG::save(const char *filename, Image & image, int jpeg_quality)
{
struct jpeg_compress_struct jpeg_compression_info;
struct jpeg_error_mgr jerr;
JSAMPROW row_pointer[1];
int row_stride;
FILE *jpg_file = fopen(filename, "wb");
if (!jpg_file) {
con_warn << "Could not write " << filename << std::endl;
return;
}
jpeg_compression_info.err = jpeg_std_error(&jerr);
jpeg_create_compress(&jpeg_compression_info);
jpeg_stdio_dest(&jpeg_compression_info, jpg_file);
jpeg_compression_info.image_width = image.width();
jpeg_compression_info.image_height = image.height();
jpeg_compression_info.input_components = image.channels();
jpeg_compression_info.in_color_space = JCS_RGB;
jpeg_set_defaults(&jpeg_compression_info);
jpeg_set_quality(&jpeg_compression_info, jpeg_quality, TRUE);
jpeg_start_compress(&jpeg_compression_info, TRUE);
row_stride = image.width() * image.channels();
while (jpeg_compression_info.next_scanline < jpeg_compression_info.image_height) {
row_pointer[0] = image[jpeg_compression_info.next_scanline * row_stride];
jpeg_write_scanlines(&jpeg_compression_info, row_pointer, 1);
}
jpeg_finish_compress(&jpeg_compression_info);
fclose(jpg_file);
jpeg_destroy_compress(&jpeg_compression_info);
con_print << "Wrote " << filename << std::endl;
}
}
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