util/directjpeg.c

   1 /* directjpeg.c- loads a jpeg file directly into a XImage
   2  *
   3  *  WindowMaker window manager
   4  *
   5  *  Copyright (c) 1999 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
  24 #include "../src/config.h"
  25
  26
  27
  28 #ifdef USE_JPEG
  29
  30 #include <stdlib.h>
  31 #include <stdio.h>
  32 #include <string.h>
  33
  34 #include <jpeglib.h>
  35
  36 #include "../wrlib/wraster.h"
  37
  38 #include <setjmp.h>
  39
  40
  41 struct my_error_mgr {
  42   struct jpeg_error_mgr pub;    /* "public" fields */
  43
  44   jmp_buf setjmp_buffer;        /* for return to caller */
  45 };
  46
  47 typedef struct my_error_mgr * my_error_ptr;
  48
  49 /*
  50  * Here's the routine that will replace the standard error_exit method:
  51  */
  52
  53 static void
  54 my_error_exit (j_common_ptr cinfo)
  55 {
  56   /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
  57   my_error_ptr myerr = (my_error_ptr) cinfo->err;
  58
  59   /* Always display the message. */
  60   /* We could postpone this until after returning, if we chose. */
  61   (*cinfo->err->output_message) (cinfo);
  62
  63   /* Return control to the setjmp point */
  64   longjmp(myerr->setjmp_buffer, 1);
  65 }
  66
  67
  68 static Bool
  69 canLoad(RContext *rc)
  70 {
  71     if (rc->depth != 16 || rc->vclass != TrueColor
  72         || rc->red_offset!=11 || rc->green_offset!=5 || rc->blue_offset!=0)
  73         return False;
  74
  75     return True;
  76 }
  77
  78
  79 static void
  80 readData(RContext *rc, struct jpeg_decompress_struct *cinfo,
  81          JSAMPROW *buffer, RXImage *ximg)
  82 {
  83     int i, j;
  84     unsigned long pixel;
  85     int y = 0;
  86
  87     /* for 16bpp only */
  88     while (cinfo->output_scanline < cinfo->output_height) {
  89
  90         jpeg_read_scanlines(cinfo, buffer, (JDIMENSION)1);
  91
  92         if (cinfo->out_color_space==JCS_RGB) {
  93             for (i=0,j=0; i<cinfo->image_width; i++) {
  94
  95                 printf("%i %i %i\n",
  96                        (((unsigned long)buffer[0][j])&0xf8)<<8,
  97                        (((unsigned long)buffer[0][j+1])&0xf4)<<3,
  98                        (((unsigned long)buffer[0][j+2]))>>3);
  99
 100                 pixel = (((unsigned long)buffer[0][j++])&0xf8)<<8
 101                     |(((unsigned long)buffer[0][j++])&0xf4)<<3
 102                     |(((unsigned long)buffer[0][j++]))>>3;
 103
 104                 XPutPixel(ximg->image, i, y, pixel);
 105             }
 106         } else {
 107             for (i=0,j=0; i<cinfo->image_width; i++, j++) {
 108
 109                 pixel = (unsigned long)buffer[0][j]<<8
 110                     |(unsigned long)buffer[0][j]<<3
 111                     |(unsigned long)buffer[0][j]>>3;
 112
 113                 XPutPixel(ximg->image, i, y, pixel);
 114             }
 115         }
 116         y++;
 117     }
 118 }
 119
 120
 121
 122 Pixmap
 123 LoadJPEG(RContext *rc, char *file_name, int *width, int *height)
 124 {
 125     struct jpeg_decompress_struct cinfo;
 126     JSAMPROW buffer[1];
 127     FILE *file;
 128     struct my_error_mgr jerr;
 129     RXImage *ximg = NULL;
 130     unsigned char buf[8];
 131     Pixmap p = None;
 132
 133     if (!canLoad(rc))
 134         return None;
 135
 136     file = fopen(file_name, "r");
 137     if (!file) {
 138         return None;
 139     }
 140     if (fread(buf, 2, 1, file) != 1) {
 141         fclose(file);
 142         return None;
 143     }
 144     if (buf[0] != 0xff || buf[1] != 0xd8) {
 145         fclose(file);
 146         return None;
 147     }
 148     rewind(file);
 149
 150     cinfo.err = jpeg_std_error(&jerr.pub);
 151     jerr.pub.error_exit = my_error_exit;
 152     /* Establish the setjmp return context for my_error_exit to use. */
 153     if (setjmp(jerr.setjmp_buffer)) {
 154        /* If we get here, the JPEG code has signaled an error.
 155         * We need to clean up the JPEG object, close the input file, and return.
 156         */
 157         jpeg_destroy_decompress(&cinfo);
 158         fclose(file);
 159
 160         if (ximg) {
 161             RDestroyXImage(rc, ximg);
 162         }
 163
 164         return None;
 165     }
 166
 167     jpeg_create_decompress(&cinfo);
 168
 169     jpeg_stdio_src(&cinfo, file);
 170
 171     jpeg_read_header(&cinfo, TRUE);
 172
 173     buffer[0] = (JSAMPROW)malloc(cinfo.image_width*cinfo.num_components);
 174     if (!buffer[0]) {
 175         RErrorCode = RERR_NOMEMORY;
 176         goto bye;
 177     }
 178
 179     if(cinfo.jpeg_color_space==JCS_GRAYSCALE) {
 180        cinfo.out_color_space=JCS_GRAYSCALE;
 181     } else
 182         cinfo.out_color_space = JCS_RGB;
 183     cinfo.quantize_colors = FALSE;
 184     cinfo.do_fancy_upsampling = FALSE;
 185     cinfo.do_block_smoothing = FALSE;
 186     jpeg_calc_output_dimensions(&cinfo);
 187
 188     ximg = RCreateXImage(rc, rc->depth, cinfo.image_width, cinfo.image_height);
 189     if (!ximg) {
 190        goto bye;
 191     }
 192     jpeg_start_decompress(&cinfo);
 193
 194     readData(rc, &cinfo, buffer, ximg);
 195
 196     jpeg_finish_decompress(&cinfo);
 197
 198     p = XCreatePixmap(rc->dpy, rc->drawable, cinfo.image_width,
 199                       cinfo.image_height, rc->depth);
 200
 201     RPutXImage(rc, p, rc->copy_gc, ximg, 0, 0, 0, 0, cinfo.image_width,
 202                cinfo.image_height);
 203
 204     *width = cinfo.image_width;
 205     *height = cinfo.image_height;
 206
 207   bye:
 208     jpeg_destroy_decompress(&cinfo);
 209
 210     fclose(file);
 211
 212     if (buffer[0])
 213         free(buffer[0]);
 214
 215     if (ximg)
 216         RDestroyXImage(rc, ximg);
 217
 218     return p;
 219 }
 220
 221 #endif /* USE_JPEG */
 222