wrlib/save_jpeg.c

   1 /* save_jpeg.c - save JPEG image
   2  *
   3  * Raster graphics library
   4  *
   5  * Copyright (c) 2023 Window Maker Team
   6  *
   7  *  This library is free software; you can redistribute it and/or
   8  *  modify it under the terms of the GNU Library General Public
   9  *  License as published by the Free Software Foundation; either
  10  *  version 2 of the License, or (at your option) any later version.
  11  *
  12  *  This library is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  *  Library General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU Library General Public
  18  *  License along with this library; if not, write to the Free
  19  *  Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  20  *  MA 02110-1301, USA.
  21  */
  22
  23 #include <config.h>
  24
  25 #include <stdlib.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <assert.h>
  29 #include <errno.h>
  30 #include <jpeglib.h>
  31
  32 #include "wraster.h"
  33 #include "imgformat.h"
  34 #include "wr_i18n.h"
  35
  36 /*
  37  *  Save RImage to JPEG image
  38  */
  39
  40 Bool RSaveJPEG(RImage *img, const char *filename, char *title)
  41 {
  42         FILE *file;
  43         int x, y, img_depth;
  44         char *buffer;
  45         RColor pixel;
  46         struct jpeg_compress_struct cinfo;
  47         struct jpeg_error_mgr jerr;
  48         JSAMPROW row_pointer;
  49
  50         file = fopen(filename, "wb");
  51         if (!file) {
  52                 RErrorCode = RERR_OPEN;
  53                 return False;
  54         }
  55
  56         if (img->format == RRGBAFormat)
  57                 img_depth = 4;
  58         else
  59                 img_depth = 3;
  60
  61         /* collect separate RGB values to a buffer */
  62         buffer = malloc(sizeof(char) * 3 * img->width * img->height);
  63         for (y = 0; y < img->height; y++) {
  64                 for (x = 0; x < img->width; x++) {
  65                         RGetPixel(img, x, y, &pixel);
  66                         buffer[y*img->width*3+x*3+0] = (char)(pixel.red);
  67                         buffer[y*img->width*3+x*3+1] = (char)(pixel.green);
  68                         buffer[y*img->width*3+x*3+2] = (char)(pixel.blue);
  69                 }
  70         }
  71
  72         /* Setup Exception handling */
  73         cinfo.err = jpeg_std_error(&jerr);
  74
  75         /* Initialize cinfo structure */
  76         jpeg_create_compress(&cinfo);
  77         jpeg_stdio_dest(&cinfo, file);
  78
  79         cinfo.image_width = img->width;
  80         cinfo.image_height = img->height;
  81         cinfo.input_components = 3;
  82         cinfo.in_color_space = JCS_RGB;
  83
  84         jpeg_set_defaults(&cinfo);
  85         jpeg_set_quality(&cinfo, 85, TRUE);
  86         jpeg_start_compress(&cinfo, TRUE);
  87
  88         /* Set title if any */
  89         if (title)
  90                 jpeg_write_marker(&cinfo, JPEG_COM, (const JOCTET*)title, strlen(title));
  91
  92         while (cinfo.next_scanline < cinfo.image_height) {
  93                 row_pointer = (JSAMPROW) &buffer[cinfo.next_scanline * img_depth * img->width];
  94                 jpeg_write_scanlines(&cinfo, &row_pointer, 1);
  95         }
  96
  97         jpeg_finish_compress(&cinfo);
  98
  99         /* Clean */
 100         free(buffer);
 101         fclose(file);
 102
 103         return True;
 104 }