Pileus Git - ~andy/gtk/blob - gdk-pixbuf/io-jpeg.c

   1 /* GdkPixbuf library - JPEG image loader
   2  *
   3  * Copyright (C) 1999 Michael Zucchi
   4  * Copyright (C) 1999 The Free Software Foundation
   5  *
   6  * Progressive loading code Copyright (C) 1999 Red Hat, Inc.
   7  *
   8  * Authors: Michael Zucchi <zucchi@zedzone.mmc.com.au>
   9  *          Federico Mena-Quintero <federico@gimp.org>
  10  *          Michael Fulbright <drmike@redhat.com>
  11  *
  12  * This library is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU Library General Public
  14  * License as published by the Free Software Foundation; either
  15  * version 2 of the License, or (at your option) any later version.
  16  *
  17  * This library is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  * Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with this library; if not, write to the
  24  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  25  * Boston, MA 02111-1307, USA.
  26  */
  27
  28
  29 /*
  30   Progressive file loading notes (11/03/1999) <drmike@redhat.com>...
  31
  32   These are issues I know of and will be dealing with shortly:
  33
  34     -  Currently does not handle progressive jpegs - this
  35        requires a change in the way image_load_increment () calls
  36        libjpeg. Progressive jpegs are rarer but I will add this
  37        support asap.
  38
  39     - error handling is not as good as it should be
  40
  41  */
  42
  43
  44 #include <config.h>
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #include <setjmp.h>
  49 #include <jpeglib.h>
  50 #include "gdk-pixbuf/gdk-pixbuf.h"
  51 #include "gdk-pixbuf/gdk-pixbuf-io.h"
  52
  53 \f
  54
  55 /* we are a "source manager" as far as libjpeg is concerned */
  56 #define JPEG_PROG_BUF_SIZE 4096
  57
  58 typedef struct {
  59         struct jpeg_source_mgr pub;   /* public fields */
  60
  61         JOCTET buffer[JPEG_PROG_BUF_SIZE];              /* start of buffer */
  62         long  skip_next;              /* number of bytes to skip next read */
  63
  64 } my_source_mgr;
  65
  66 typedef my_source_mgr * my_src_ptr;
  67
  68 /* error handler data */
  69 struct error_handler_data {
  70         struct jpeg_error_mgr pub;
  71         sigjmp_buf setjmp_buffer;
  72 };
  73
  74 /* progressive loader context */
  75 typedef struct {
  76         ModuleUpdatedNotifyFunc  updated_func;
  77         ModulePreparedNotifyFunc prepared_func;
  78         gpointer                 user_data;
  79
  80         GdkPixbuf                *pixbuf;
  81         guchar                   *dptr;   /* current position in pixbuf */
  82
  83         gboolean                 did_prescan;  /* are we in image data yet? */
  84         gboolean                 got_header;  /* have we loaded jpeg header? */
  85         gboolean                 src_initialized;/* TRUE when jpeg lib initialized */
  86         struct jpeg_decompress_struct cinfo;
  87         struct error_handler_data     jerr;
  88 } JpegProgContext;
  89
  90 GdkPixbuf *image_load (FILE *f);
  91 gpointer image_begin_load (ModulePreparedNotifyFunc func,
  92                            ModuleUpdatedNotifyFunc func2, gpointer user_data);
  93 void image_stop_load (gpointer context);
  94 gboolean image_load_increment(gpointer context, guchar *buf, guint size);
  95
  96
  97 static void
  98 fatal_error_handler (j_common_ptr cinfo)
  99 {
 100         /* FIXME:
 101          * We should somehow signal what error occurred to the caller so the
 102          * caller can handle the error message */
 103         struct error_handler_data *errmgr;
 104
 105         errmgr = (struct error_handler_data *) cinfo->err;
 106         cinfo->err->output_message (cinfo);
 107         siglongjmp (errmgr->setjmp_buffer, 1);
 108         return;
 109 }
 110
 111 /* Destroy notification function for the libart pixbuf */
 112 static void
 113 free_buffer (gpointer user_data, gpointer data)
 114 {
 115         free (data);
 116 }
 117
 118
 119 /* explode gray image data from jpeg library into rgb components in pixbuf */
 120 static void
 121 explode_gray_into_buf (struct jpeg_decompress_struct *cinfo,
 122                        guchar **lines)
 123 {
 124         gint i, j;
 125         guint w;
 126
 127         g_return_if_fail (cinfo != NULL);
 128         g_return_if_fail (cinfo->output_components == 1);
 129
 130         /* Expand grey->colour.  Expand from the end of the
 131          * memory down, so we can use the same buffer.
 132          */
 133         w = cinfo->image_width;
 134         for (i = cinfo->rec_outbuf_height - 1; i >= 0; i--) {
 135                 guchar *from, *to;
 136
 137                 from = lines[i] + w - 1;
 138                 to = lines[i] + (w - 1) * 3;
 139                 for (j = w - 1; j >= 0; j--) {
 140                         to[0] = from[0];
 141                         to[1] = from[0];
 142                         to[2] = from[0];
 143                         to -= 3;
 144                         from--;
 145                 }
 146         }
 147 }
 148
 149 /* Shared library entry point */
 150 GdkPixbuf *
 151 image_load (FILE *f)
 152 {
 153         gint w, h, i;
 154         guchar *pixels = NULL;
 155         guchar *dptr;
 156         guchar *lines[4]; /* Used to expand rows, via rec_outbuf_height,
 157                            * from the header file:
 158                            * " Usually rec_outbuf_height will be 1 or 2,
 159                            * at most 4."
 160                            */
 161         guchar **lptr;
 162         struct jpeg_decompress_struct cinfo;
 163         struct error_handler_data jerr;
 164
 165         /* setup error handler */
 166         cinfo.err = jpeg_std_error (&jerr.pub);
 167         jerr.pub.error_exit = fatal_error_handler;
 168
 169         if (sigsetjmp (jerr.setjmp_buffer, 1)) {
 170                 /* Whoops there was a jpeg error */
 171                 if (pixels)
 172                         free (pixels);
 173
 174                 jpeg_destroy_decompress (&cinfo);
 175                 return NULL;
 176         }
 177
 178         /* load header, setup */
 179         jpeg_create_decompress (&cinfo);
 180         jpeg_stdio_src (&cinfo, f);
 181         jpeg_read_header (&cinfo, TRUE);
 182         jpeg_start_decompress (&cinfo);
 183         cinfo.do_fancy_upsampling = FALSE;
 184         cinfo.do_block_smoothing = FALSE;
 185
 186         w = cinfo.output_width;
 187         h = cinfo.output_height;
 188
 189         pixels = g_malloc (h * w * 3);
 190         if (!pixels) {
 191                 jpeg_destroy_decompress (&cinfo);
 192                 return NULL;
 193         }
 194
 195         dptr = pixels;
 196
 197         /* decompress all the lines, a few at a time */
 198
 199         while (cinfo.output_scanline < cinfo.output_height) {
 200                 lptr = lines;
 201                 for (i = 0; i < cinfo.rec_outbuf_height; i++) {
 202                         *lptr++ = dptr;
 203                         dptr += w * 3;
 204                 }
 205
 206                 jpeg_read_scanlines (&cinfo, lines, cinfo.rec_outbuf_height);
 207
 208                 if (cinfo.output_components == 1)
 209                         explode_gray_into_buf (&cinfo, lines);
 210         }
 211
 212         jpeg_finish_decompress (&cinfo);
 213         jpeg_destroy_decompress (&cinfo);
 214
 215         return gdk_pixbuf_new_from_data (pixels, ART_PIX_RGB, FALSE,
 216                                          w, h, w * 3,
 217                                          free_buffer, NULL);
 218 }
 219
 220
 221 /**** Progressive image loading handling *****/
 222
 223 /* these routines required because we are acting as a source manager for */
 224 /* libjpeg. */
 225 static void
 226 init_source (j_decompress_ptr cinfo)
 227 {
 228         my_src_ptr src = (my_src_ptr) cinfo->src;
 229
 230         src->skip_next = 0;
 231 }
 232
 233
 234 static void
 235 term_source (j_decompress_ptr cinfo)
 236 {
 237         /* XXXX - probably should scream something has happened */
 238 }
 239
 240
 241 /* for progressive loading (called "I/O Suspension" by libjpeg docs) */
 242 /* we do nothing except return "FALSE"                               */
 243 static boolean
 244 fill_input_buffer (j_decompress_ptr cinfo)
 245 {
 246         return FALSE;
 247 }
 248
 249
 250 static void
 251 skip_input_data (j_decompress_ptr cinfo, long num_bytes)
 252 {
 253         my_src_ptr src = (my_src_ptr) cinfo->src;
 254         long   num_can_do;
 255
 256         /* move as far as we can into current buffer */
 257         /* then set skip_next to catch the rest      */
 258         if (num_bytes > 0) {
 259                 num_can_do = MIN (src->pub.bytes_in_buffer, num_bytes);
 260                 src->pub.next_input_byte += (size_t) num_can_do;
 261                 src->pub.bytes_in_buffer -= (size_t) num_can_do;
 262
 263                 src->skip_next = num_bytes - num_can_do;
 264         }
 265 }
 266
 267
 268 /*
 269  * func - called when we have pixmap created (but no image data)
 270  * user_data - passed as arg 1 to func
 271  * return context (opaque to user)
 272  */
 273
 274 gpointer
 275 image_begin_load (ModulePreparedNotifyFunc prepared_func,
 276                   ModuleUpdatedNotifyFunc  updated_func,
 277                   gpointer user_data)
 278 {
 279         JpegProgContext *context;
 280         my_source_mgr   *src;
 281
 282         context = g_new0 (JpegProgContext, 1);
 283         context->prepared_func = prepared_func;
 284         context->updated_func  = updated_func;
 285         context->user_data = user_data;
 286         context->pixbuf = NULL;
 287         context->got_header = FALSE;
 288         context->did_prescan = FALSE;
 289         context->src_initialized = FALSE;
 290
 291         /* create libjpeg structures */
 292         jpeg_create_decompress (&context->cinfo);
 293
 294         context->cinfo.src = (struct jpeg_source_mgr *) g_new0 (my_source_mgr, 1);
 295         src = (my_src_ptr) context->cinfo.src;
 296
 297         context->cinfo.err = jpeg_std_error (&context->jerr.pub);
 298
 299         src = (my_src_ptr) context->cinfo.src;
 300         src->pub.init_source = init_source;
 301         src->pub.fill_input_buffer = fill_input_buffer;
 302         src->pub.skip_input_data = skip_input_data;
 303         src->pub.resync_to_restart = jpeg_resync_to_restart;
 304         src->pub.term_source = term_source;
 305         src->pub.bytes_in_buffer = 0;
 306         src->pub.next_input_byte = NULL;
 307
 308         return (gpointer) context;
 309 }
 310
 311 /*
 312  * context - returned from image_begin_load
 313  *
 314  * free context, unref gdk_pixbuf
 315  */
 316 void
 317 image_stop_load (gpointer data)
 318 {
 319         JpegProgContext *context = (JpegProgContext *) data;
 320
 321         g_return_if_fail (context != NULL);
 322
 323         if (context->pixbuf)
 324                 gdk_pixbuf_unref (context->pixbuf);
 325
 326         jpeg_finish_decompress(&context->cinfo);
 327         jpeg_destroy_decompress(&context->cinfo);
 328
 329         if (context->cinfo.src) {
 330                 my_src_ptr src = (my_src_ptr) context->cinfo.src;
 331
 332                 g_free (src);
 333         }
 334
 335         g_free (context);
 336 }
 337
 338
 339
 340
 341 /*
 342  * context - from image_begin_load
 343  * buf - new image data
 344  * size - length of new image data
 345  *
 346  * append image data onto inrecrementally built output image
 347  */
 348 gboolean
 349 image_load_increment (gpointer data, guchar *buf, guint size)
 350 {
 351         JpegProgContext *context = (JpegProgContext *)data;
 352         struct jpeg_decompress_struct *cinfo;
 353         my_src_ptr  src;
 354         guint       num_left, num_copy;
 355         guint       last_bytes_left;
 356         guint       spinguard;
 357         gboolean    first;
 358         guchar *bufhd;
 359
 360         g_return_val_if_fail (context != NULL, FALSE);
 361         g_return_val_if_fail (buf != NULL, FALSE);
 362
 363         src = (my_src_ptr) context->cinfo.src;
 364
 365         cinfo = &context->cinfo;
 366
 367         /* XXXXXXX (drmike) - loop(s) below need to be recoded now I
 368          *                    have a grasp of what the flow needs to be!
 369          */
 370
 371
 372         /* skip over data if requested, handle unsigned int sizes cleanly */
 373         /* only can happen if we've already called jpeg_get_header once   */
 374         if (context->src_initialized && src->skip_next) {
 375                 if (src->skip_next > size) {
 376                         src->skip_next -= size;
 377                         return TRUE;
 378                 } else {
 379                         num_left = size - src->skip_next;
 380                         bufhd = buf + src->skip_next;
 381                         src->skip_next = 0;
 382                 }
 383         } else {
 384                 num_left = size;
 385                 bufhd = buf;
 386         }
 387
 388         if (num_left == 0)
 389                 return TRUE;
 390
 391         last_bytes_left = 0;
 392         spinguard = 0;
 393         first = TRUE;
 394         while (TRUE) {
 395
 396                 /* handle any data from caller we haven't processed yet */
 397                 if (num_left > 0) {
 398                         if(src->pub.bytes_in_buffer &&
 399                            src->pub.next_input_byte != src->buffer)
 400                                 memmove(src->buffer, src->pub.next_input_byte,
 401                                         src->pub.bytes_in_buffer);
 402
 403
 404                         num_copy = MIN (JPEG_PROG_BUF_SIZE - src->pub.bytes_in_buffer,
 405                                         num_left);
 406
 407 /*                      if (num_copy == 0)
 408                                 g_error ("Buffer overflow!");
 409 */
 410                         memcpy(src->buffer + src->pub.bytes_in_buffer, bufhd,num_copy);
 411                         src->pub.next_input_byte = src->buffer;
 412                         src->pub.bytes_in_buffer += num_copy;
 413                         bufhd += num_copy;
 414                         num_left -= num_copy;
 415                 } else {
 416                 /* did anything change from last pass, if not return */
 417                         if (first) {
 418                                 last_bytes_left = src->pub.bytes_in_buffer;
 419                                 first = FALSE;
 420                         } else if (src->pub.bytes_in_buffer == last_bytes_left)
 421                                 spinguard++;
 422                         else
 423                                 last_bytes_left = src->pub.bytes_in_buffer;
 424                 }
 425
 426                 /* should not go through twice and not pull bytes out of buf */
 427                 if (spinguard > 2)
 428                         return TRUE;
 429
 430                 /* try to load jpeg header */
 431                 if (!context->got_header) {
 432                         int rc;
 433
 434                         rc = jpeg_read_header (cinfo, TRUE);
 435                         context->src_initialized = TRUE;
 436
 437                         if (rc == JPEG_SUSPENDED)
 438                                 continue;
 439
 440                         context->got_header = TRUE;
 441
 442 #if 0
 443                         if (jpeg_has_multiple_scans (cinfo)) {
 444                                 g_print ("io-jpeg.c: Does not currently "
 445                                          "support progressive jpeg files.\n");
 446                                 return FALSE;
 447                         }
 448 #endif
 449                         context->pixbuf = gdk_pixbuf_new(ART_PIX_RGB,
 450                                                          /*have_alpha*/ FALSE,
 451                                                          8,
 452                                                          cinfo->image_width,
 453                                                          cinfo->image_height);
 454
 455                         if (context->pixbuf == NULL) {
 456                                 /* Failed to allocate memory */
 457                                 g_error ("Couldn't allocate gdkpixbuf");
 458                         }
 459
 460                         /* Use pixbuf buffer to store decompressed data */
 461                         context->dptr = context->pixbuf->art_pixbuf->pixels;
 462
 463                         /* Notify the client that we are ready to go */
 464                         (* context->prepared_func) (context->pixbuf,
 465                                                     context->user_data);
 466
 467                 } else if (!context->did_prescan) {
 468                         int rc;
 469
 470                         /* start decompression */
 471                         rc = jpeg_start_decompress (cinfo);
 472                         cinfo->do_fancy_upsampling = FALSE;
 473                         cinfo->do_block_smoothing = FALSE;
 474
 475                         if (rc == JPEG_SUSPENDED)
 476                                 continue;
 477
 478                         context->did_prescan = TRUE;
 479                 } else {
 480
 481                         /* we're decompressing so feed jpeg lib scanlines */
 482                         guchar *lines[4];
 483                         guchar **lptr;
 484                         guchar *rowptr;
 485                         gint   nlines, i;
 486                         gint   start_scanline;
 487
 488                         /* keep going until we've done all scanlines */
 489                         while (cinfo->output_scanline < cinfo->output_height) {
 490                                 start_scanline = cinfo->output_scanline;
 491                                 lptr = lines;
 492                                 rowptr = context->dptr;
 493                                 for (i=0; i < cinfo->rec_outbuf_height; i++) {
 494                                         *lptr++ = rowptr;
 495                                         rowptr += context->pixbuf->art_pixbuf->rowstride;
 496                                 }
 497
 498                                 nlines = jpeg_read_scanlines (cinfo, lines,
 499                                                               cinfo->rec_outbuf_height);
 500                                 if (nlines == 0)
 501                                         break;
 502
 503                                 /* handle gray */
 504                                 if (cinfo->output_components == 1)
 505                                         explode_gray_into_buf (cinfo, lines);
 506
 507                                 context->dptr += nlines * context->pixbuf->art_pixbuf->rowstride;
 508
 509                                 /* send updated signal */
 510                                 (* context->updated_func) (context->pixbuf,
 511                                                  context->user_data,
 512                                                  0,
 513                                                  cinfo->output_scanline-1,
 514                                                  cinfo->image_width,
 515                                                  nlines);
 516
 517 #undef DEBUG_JPEG_PROGRESSIVE
 518 #ifdef DEBUG_JPEG_PROGRESSIVE
 519
 520                                 if (start_scanline != cinfo->output_scanline)
 521                                         g_print("jpeg: Input pass=%2d, next input scanline=%3d,"
 522                                                 " emitted %3d - %3d\n",
 523                                                 cinfo->input_scan_number, cinfo->input_iMCU_row * 16,
 524                                                 start_scanline, cinfo->output_scanline - 1);
 525
 526
 527
 528                                 g_print ("Scanline %d of %d - ",
 529                                          cinfo->output_scanline,
 530                                          cinfo->output_height);
 531 /*                      g_print ("rec_height %d -", cinfo->rec_outbuf_height); */
 532                                 g_print ("Processed %d lines - bytes left = %d\n",
 533                                          nlines, cinfo->src->bytes_in_buffer);
 534 #endif
 535                         }
 536                         /* did entire image */
 537                         if (cinfo->output_scanline >= cinfo->output_height)
 538                                 return TRUE;
 539                         else
 540                                 continue;
 541                 }
 542         }
 543
 544         return TRUE;
 545 }