util/directjpeg.c

   1 /* directjpeg.c- loads a jpeg file directly into a XImage
   2  *
   3  *  WindowMaker window manager
   4  *
   5  *  Copyright (c) 1999-2003 Alfredo K. Kojima
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program 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
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  20  *  USA.
  21  */
  22
  23 #include "../src/config.h"
  24
  25 #ifdef USE_JPEG
  26
  27 #include <stdlib.h>
  28 #include <stdio.h>
  29 #include <string.h>
  30
  31 #include <jpeglib.h>
  32
  33 #include "../wrlib/wraster.h"
  34
  35 #include <setjmp.h>
  36
  37 struct my_error_mgr {
  38         struct jpeg_error_mgr pub;      /* "public" fields */
  39
  40         jmp_buf setjmp_buffer;  /* for return to caller */
  41 };
  42
  43 typedef struct my_error_mgr *my_error_ptr;
  44
  45 /*
  46  * Here's the routine that will replace the standard error_exit method:
  47  */
  48
  49 static void my_error_exit(j_common_ptr cinfo)
  50 {
  51         /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
  52         my_error_ptr myerr = (my_error_ptr) cinfo->err;
  53
  54         /* Always display the message. */
  55         /* We could postpone this until after returning, if we chose. */
  56         (*cinfo->err->output_message) (cinfo);
  57
  58         /* Return control to the setjmp point */
  59         longjmp(myerr->setjmp_buffer, 1);
  60 }
  61
  62 static Bool canLoad(RContext * rc)
  63 {
  64         if (rc->depth != 16 || rc->vclass != TrueColor
  65             || rc->red_offset != 11 || rc->green_offset != 5 || rc->blue_offset != 0)
  66                 return False;
  67
  68         return True;
  69 }
  70
  71 static void readData(RContext * rc, struct jpeg_decompress_struct *cinfo, JSAMPROW * buffer, RXImage * ximg)
  72 {
  73         int i, j;
  74         unsigned long pixel;
  75         int y = 0;
  76
  77         /* for 16bpp only */
  78         while (cinfo->output_scanline < cinfo->output_height) {
  79
  80                 jpeg_read_scanlines(cinfo, buffer, (JDIMENSION) 1);
  81
  82                 if (cinfo->out_color_space == JCS_RGB) {
  83                         for (i = 0, j = 0; i < cinfo->image_width; i++) {
  84
  85                                 printf("%i %i %i\n",
  86                                        (((unsigned long)buffer[0][j]) & 0xf8) << 8,
  87                                        (((unsigned long)buffer[0][j + 1]) & 0xf4) << 3,
  88                                        (((unsigned long)buffer[0][j + 2])) >> 3);
  89
  90                                 pixel = (((unsigned long)buffer[0][j++]) & 0xf8) << 8
  91                                     | (((unsigned long)buffer[0][j++]) & 0xf4) << 3
  92                                     | (((unsigned long)buffer[0][j++])) >> 3;
  93
  94                                 XPutPixel(ximg->image, i, y, pixel);
  95                         }
  96                 } else {
  97                         for (i = 0, j = 0; i < cinfo->image_width; i++, j++) {
  98
  99                                 pixel = (unsigned long)buffer[0][j] << 8
 100                                     | (unsigned long)buffer[0][j] << 3 | (unsigned long)buffer[0][j] >> 3;
 101
 102                                 XPutPixel(ximg->image, i, y, pixel);
 103                         }
 104                 }
 105                 y++;
 106         }
 107 }
 108
 109 Pixmap LoadJPEG(RContext * rc, char *file_name, int *width, int *height)
 110 {
 111         struct jpeg_decompress_struct cinfo;
 112         JSAMPROW buffer[1];
 113         FILE *file;
 114         struct my_error_mgr jerr;
 115         RXImage *ximg = NULL;
 116         unsigned char buf[8];
 117         Pixmap p = None;
 118
 119         if (!canLoad(rc))
 120                 return None;
 121
 122         file = fopen(file_name, "rb");
 123         if (!file) {
 124                 return None;
 125         }
 126         if (fread(buf, 2, 1, file) != 1) {
 127                 fclose(file);
 128                 return None;
 129         }
 130         if (buf[0] != 0xff || buf[1] != 0xd8) {
 131                 fclose(file);
 132                 return None;
 133         }
 134         rewind(file);
 135
 136         cinfo.err = jpeg_std_error(&jerr.pub);
 137         jerr.pub.error_exit = my_error_exit;
 138         /* Establish the setjmp return context for my_error_exit to use. */
 139         if (setjmp(jerr.setjmp_buffer)) {
 140                 /* If we get here, the JPEG code has signaled an error.
 141                  * We need to clean up the JPEG object, close the input file, and return.
 142                  */
 143                 jpeg_destroy_decompress(&cinfo);
 144                 fclose(file);
 145
 146                 if (ximg) {
 147                         RDestroyXImage(rc, ximg);
 148                 }
 149
 150                 return None;
 151         }
 152
 153         jpeg_create_decompress(&cinfo);
 154
 155         jpeg_stdio_src(&cinfo, file);
 156
 157         jpeg_read_header(&cinfo, TRUE);
 158
 159         buffer[0] = (JSAMPROW) malloc(cinfo.image_width * cinfo.num_components);
 160         if (!buffer[0]) {
 161                 RErrorCode = RERR_NOMEMORY;
 162                 goto bye;
 163         }
 164
 165         if (cinfo.jpeg_color_space == JCS_GRAYSCALE) {
 166                 cinfo.out_color_space = JCS_GRAYSCALE;
 167         } else
 168                 cinfo.out_color_space = JCS_RGB;
 169         cinfo.quantize_colors = FALSE;
 170         cinfo.do_fancy_upsampling = FALSE;
 171         cinfo.do_block_smoothing = FALSE;
 172         jpeg_calc_output_dimensions(&cinfo);
 173
 174         ximg = RCreateXImage(rc, rc->depth, cinfo.image_width, cinfo.image_height);
 175         if (!ximg) {
 176                 goto bye;
 177         }
 178         jpeg_start_decompress(&cinfo);
 179
 180         readData(rc, &cinfo, buffer, ximg);
 181
 182         jpeg_finish_decompress(&cinfo);
 183
 184         p = XCreatePixmap(rc->dpy, rc->drawable, cinfo.image_width, cinfo.image_height, rc->depth);
 185
 186         RPutXImage(rc, p, rc->copy_gc, ximg, 0, 0, 0, 0, cinfo.image_width, cinfo.image_height);
 187
 188         *width = cinfo.image_width;
 189         *height = cinfo.image_height;
 190
 191  bye:
 192         jpeg_destroy_decompress(&cinfo);
 193
 194         fclose(file);
 195
 196         if (buffer[0])
 197                 free(buffer[0]);
 198
 199         if (ximg)
 200                 RDestroyXImage(rc, ximg);
 201
 202         return p;
 203 }
 204
 205 #endif                          /* USE_JPEG */