src/image_load_jpeg.c

   1
   2 #include "main.h"
   3 #include "image-load.h"
   4 #include "image_load_jpeg.h"
   5
   6 #include <setjmp.h>
   7 #include <jpeglib.h>
   8 #include <jerror.h>
   9
  10 typedef struct _ImageLoaderJpeg ImageLoaderJpeg;
  11 struct _ImageLoaderJpeg {
  12         ImageLoaderBackendCbAreaUpdated area_updated_cb;
  13         ImageLoaderBackendCbSize size_cb;
  14         ImageLoaderBackendCbAreaPrepared area_prepared_cb;
  15
  16         gpointer data;
  17
  18         GdkPixbuf *pixbuf;
  19         guint requested_width;
  20         guint requested_height;
  21
  22         gboolean abort;
  23
  24 };
  25
  26 /* error handler data */
  27 struct error_handler_data {
  28         struct jpeg_error_mgr pub;
  29         sigjmp_buf setjmp_buffer;
  30         GError **error;
  31 };
  32
  33 /* explode gray image data from jpeg library into rgb components in pixbuf */
  34 static void
  35 explode_gray_into_buf (struct jpeg_decompress_struct *cinfo,
  36                        guchar **lines)
  37 {
  38         gint i, j;
  39         guint w;
  40
  41         g_return_if_fail (cinfo != NULL);
  42         g_return_if_fail (cinfo->output_components == 1);
  43         g_return_if_fail (cinfo->out_color_space == JCS_GRAYSCALE);
  44
  45         /* Expand grey->colour.  Expand from the end of the
  46          * memory down, so we can use the same buffer.
  47          */
  48         w = cinfo->output_width;
  49         for (i = cinfo->rec_outbuf_height - 1; i >= 0; i--) {
  50                 guchar *from, *to;
  51
  52                 from = lines[i] + w - 1;
  53                 to = lines[i] + (w - 1) * 3;
  54                 for (j = w - 1; j >= 0; j--) {
  55                         to[0] = from[0];
  56                         to[1] = from[0];
  57                         to[2] = from[0];
  58                         to -= 3;
  59                         from--;
  60                 }
  61         }
  62 }
  63
  64
  65 static void
  66 convert_cmyk_to_rgb (struct jpeg_decompress_struct *cinfo,
  67                      guchar **lines)
  68 {
  69         gint i, j;
  70
  71         g_return_if_fail (cinfo != NULL);
  72         g_return_if_fail (cinfo->output_components == 4);
  73         g_return_if_fail (cinfo->out_color_space == JCS_CMYK);
  74
  75         for (i = cinfo->rec_outbuf_height - 1; i >= 0; i--) {
  76                 guchar *p;
  77
  78                 p = lines[i];
  79                 for (j = 0; j < cinfo->output_width; j++) {
  80                         int c, m, y, k;
  81                         c = p[0];
  82                         m = p[1];
  83                         y = p[2];
  84                         k = p[3];
  85                         if (cinfo->saw_Adobe_marker) {
  86                                 p[0] = k*c / 255;
  87                                 p[1] = k*m / 255;
  88                                 p[2] = k*y / 255;
  89                         }
  90                         else {
  91                                 p[0] = (255 - k)*(255 - c) / 255;
  92                                 p[1] = (255 - k)*(255 - m) / 255;
  93                                 p[2] = (255 - k)*(255 - y) / 255;
  94                         }
  95                         p[3] = 255;
  96                         p += 4;
  97                 }
  98         }
  99 }
 100
 101
 102 static gpointer image_loader_jpeg_new(ImageLoaderBackendCbAreaUpdated area_updated_cb, ImageLoaderBackendCbSize size_cb, ImageLoaderBackendCbAreaPrepared area_prepared_cb, gpointer data)
 103 {
 104         ImageLoaderJpeg *loader = g_new0(ImageLoaderJpeg, 1);
 105
 106         loader->area_updated_cb = area_updated_cb;
 107         loader->size_cb = size_cb;
 108         loader->area_prepared_cb = area_prepared_cb;
 109         loader->data = data;
 110         return (gpointer) loader;
 111 }
 112
 113 static void
 114 fatal_error_handler (j_common_ptr cinfo)
 115 {
 116         struct error_handler_data *errmgr;
 117         char buffer[JMSG_LENGTH_MAX];
 118
 119         errmgr = (struct error_handler_data *) cinfo->err;
 120
 121         /* Create the message */
 122         (* cinfo->err->format_message) (cinfo, buffer);
 123
 124         /* broken check for *error == NULL for robustness against
 125          * crappy JPEG library
 126          */
 127         if (errmgr->error && *errmgr->error == NULL) {
 128                 g_set_error (errmgr->error,
 129                              GDK_PIXBUF_ERROR,
 130                              cinfo->err->msg_code == JERR_OUT_OF_MEMORY
 131                              ? GDK_PIXBUF_ERROR_INSUFFICIENT_MEMORY
 132                              : GDK_PIXBUF_ERROR_CORRUPT_IMAGE,
 133                              _("Error interpreting JPEG image file (%s)"),
 134                              buffer);
 135         }
 136
 137         siglongjmp (errmgr->setjmp_buffer, 1);
 138
 139         g_assert_not_reached ();
 140 }
 141
 142 static void
 143 output_message_handler (j_common_ptr cinfo)
 144 {
 145   /* This method keeps libjpeg from dumping crap to stderr */
 146
 147   /* do nothing */
 148 }
 149
 150 static gboolean image_loader_jpeg_load (gpointer loader, const guchar *buf, gsize count, GError **error)
 151 {
 152         ImageLoaderJpeg *lj = (ImageLoaderJpeg *) loader;
 153         struct jpeg_decompress_struct cinfo;
 154         guchar *dptr;
 155         guint rowstride;
 156
 157         struct error_handler_data jerr;
 158 //      stdio_src_ptr src;
 159
 160         /* setup error handler */
 161         cinfo.err = jpeg_std_error (&jerr.pub);
 162         jerr.pub.error_exit = fatal_error_handler;
 163         jerr.pub.output_message = output_message_handler;
 164
 165         jerr.error = error;
 166
 167
 168         if (setjmp(jerr.setjmp_buffer))
 169                 {
 170                 /* If we get here, the JPEG code has signaled an error.
 171                  * We need to clean up the JPEG object, close the input file, and return.
 172                 */
 173                 jpeg_destroy_decompress(&cinfo);
 174                 return FALSE;
 175                 }
 176
 177         jpeg_create_decompress(&cinfo);
 178
 179         jpeg_mem_src(&cinfo, (unsigned char *)buf, count);
 180
 181
 182         jpeg_read_header(&cinfo, TRUE);
 183
 184         lj->requested_width = cinfo.image_width;
 185         lj->requested_height = cinfo.image_height;
 186         lj->size_cb(loader, cinfo.image_width, cinfo.image_height, lj->data);
 187
 188         cinfo.scale_num = 1;
 189         for (cinfo.scale_denom = 2; cinfo.scale_denom <= 8; cinfo.scale_denom *= 2) {
 190                 jpeg_calc_output_dimensions(&cinfo);
 191                 if (cinfo.output_width < lj->requested_width || cinfo.output_height < lj->requested_height) {
 192                         cinfo.scale_denom /= 2;
 193                         break;
 194                 }
 195         }
 196         jpeg_calc_output_dimensions(&cinfo);
 197
 198         jpeg_start_decompress(&cinfo);
 199
 200         lj->pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB,
 201                                      cinfo.out_color_components == 4 ? TRUE : FALSE,
 202                                      8, cinfo.output_width, cinfo.output_height);
 203
 204         lj->area_prepared_cb(loader, lj->data);
 205         rowstride = gdk_pixbuf_get_rowstride(lj->pixbuf);
 206         dptr = gdk_pixbuf_get_pixels(lj->pixbuf);
 207
 208         if (!lj->pixbuf)
 209                 {
 210                 jpeg_destroy_decompress (&cinfo);
 211                 return 0;
 212                 }
 213
 214         while (cinfo.output_scanline < cinfo.output_height && !lj->abort)
 215                 {
 216                 guchar *lines[4];
 217                 guchar **lptr;
 218                 gint i;
 219                 guint scanline = cinfo.output_scanline;
 220
 221                 lptr = lines;
 222                 for (i = 0; i < cinfo.rec_outbuf_height; i++)
 223                         {
 224                         *lptr++ = dptr;
 225                         dptr += rowstride;
 226                         }
 227
 228                 jpeg_read_scanlines (&cinfo, lines, cinfo.rec_outbuf_height);
 229
 230                 switch (cinfo.out_color_space)
 231                         {
 232                             case JCS_GRAYSCALE:
 233                               explode_gray_into_buf (&cinfo, lines);
 234                               break;
 235                             case JCS_RGB:
 236                               /* do nothing */
 237                               break;
 238                             case JCS_CMYK:
 239                               convert_cmyk_to_rgb (&cinfo, lines);
 240                               break;
 241                             default:
 242                               break;
 243                         }
 244                 lj->area_updated_cb(loader, 0, scanline, cinfo.output_width, cinfo.rec_outbuf_height, lj->data);
 245                 }
 246
 247         jpeg_finish_decompress(&cinfo);
 248         jpeg_destroy_decompress(&cinfo);
 249         return TRUE;
 250 }
 251
 252 static void image_loader_jpeg_set_size(gpointer loader, int width, int height)
 253 {
 254         ImageLoaderJpeg *lj = (ImageLoaderJpeg *) loader;
 255         lj->requested_width = width;
 256         lj->requested_height = height;
 257 }
 258
 259 static GdkPixbuf* image_loader_jpeg_get_pixbuf(gpointer loader)
 260 {
 261         ImageLoaderJpeg *lj = (ImageLoaderJpeg *) loader;
 262         return lj->pixbuf;
 263 }
 264
 265 static gchar* image_loader_jpeg_get_format_name(gpointer loader)
 266 {
 267         return g_strdup("jpeg");
 268 }
 269 static gchar** image_loader_jpeg_get_format_mime_types(gpointer loader)
 270 {
 271         static gchar *mime[] = {"image/jpeg", NULL};
 272         return g_strdupv(mime);
 273 }
 274
 275 static gboolean image_loader_jpeg_close(gpointer loader, GError **error)
 276 {
 277         return TRUE;
 278 }
 279
 280 static void image_loader_jpeg_abort(gpointer loader)
 281 {
 282         ImageLoaderJpeg *lj = (ImageLoaderJpeg *) loader;
 283         lj->abort = TRUE;
 284 }
 285
 286 static void image_loader_jpeg_free(gpointer loader)
 287 {
 288         ImageLoaderJpeg *lj = (ImageLoaderJpeg *) loader;
 289         if (lj->pixbuf) g_object_unref(lj->pixbuf);
 290         g_free(lj);
 291 }
 292
 293
 294 void image_loader_backend_set_jpeg(ImageLoaderBackend *funcs)
 295 {
 296         funcs->loader_new = image_loader_jpeg_new;
 297         funcs->set_size = image_loader_jpeg_set_size;
 298         funcs->load = image_loader_jpeg_load;
 299         funcs->write = NULL;
 300         funcs->get_pixbuf = image_loader_jpeg_get_pixbuf;
 301         funcs->close = image_loader_jpeg_close;
 302         funcs->abort = image_loader_jpeg_abort;
 303         funcs->free = image_loader_jpeg_free;
 304
 305         funcs->get_format_name = image_loader_jpeg_get_format_name;
 306         funcs->get_format_mime_types = image_loader_jpeg_get_format_mime_types;
 307 }
 308
 309
 310