images/io-libpng.c

   1 /*
   2  *      Image Library -- libpng
   3  *
   4  *      (c) 2006 Pavel Charvat <pchar@ucw.cz>
   5  *
   6  *      This software may be freely distributed and used according to the terms
   7  *      of the GNU Lesser General Public License.
   8  */
   9
  10 #undef LOCAL_DEBUG
  11
  12 #include "ucw/lib.h"
  13 #include "ucw/mempool.h"
  14 #include "ucw/fastbuf.h"
  15 #include "images/images.h"
  16 #include "images/error.h"
  17 #include "images/color.h"
  18 #include "images/io-main.h"
  19
  20 #include <png.h>
  21 #include <setjmp.h>
  22
  23 struct libpng_read_data {
  24   png_structp png_ptr;
  25   png_infop info_ptr;
  26   png_infop end_ptr;
  27   png_uint_32 cols;
  28   png_uint_32 rows;
  29   int bit_depth;
  30   int color_type;
  31 };
  32
  33 static png_voidp
  34 libpng_malloc(png_structp png_ptr, png_size_t size)
  35 {
  36   DBG("libpng_malloc(size=%u)", (uns)size);
  37   return mp_alloc(png_get_mem_ptr(png_ptr), size);
  38 }
  39
  40 static void
  41 libpng_free(png_structp png_ptr UNUSED, png_voidp ptr UNUSED)
  42 {
  43   DBG("libpng_free()");
  44 }
  45
  46 static void NONRET
  47 libpng_read_error(png_structp png_ptr, png_const_charp msg)
  48 {
  49   DBG("libpng_read_error()");
  50   IMAGE_ERROR(png_get_error_ptr(png_ptr), IMAGE_ERROR_READ_FAILED, "%s", msg);
  51   longjmp(png_jmpbuf(png_ptr), 1);
  52 }
  53
  54 static void NONRET
  55 libpng_write_error(png_structp png_ptr, png_const_charp msg)
  56 {
  57   DBG("libpng_write_error()");
  58   IMAGE_ERROR(png_get_error_ptr(png_ptr), IMAGE_ERROR_WRITE_FAILED, "%s", msg);
  59   longjmp(png_jmpbuf(png_ptr), 1);
  60 }
  61
  62 static void
  63 libpng_warning(png_structp png_ptr UNUSED, png_const_charp msg UNUSED)
  64 {
  65   DBG("libpng_warning(): %s", (byte *)msg);
  66 }
  67
  68 static void
  69 libpng_read_fn(png_structp png_ptr, png_bytep data, png_size_t length)
  70 {
  71   DBG("libpng_read_fn(len=%u)", (uns)length);
  72   if (unlikely(bread((struct fastbuf *)png_get_io_ptr(png_ptr), (byte *)data, length) < length))
  73     png_error(png_ptr, "Incomplete data");
  74 }
  75
  76 static void
  77 libpng_write_fn(png_structp png_ptr, png_bytep data, png_size_t length)
  78 {
  79   DBG("libpng_write_fn(len=%u)", (uns)length);
  80   bwrite((struct fastbuf *)png_get_io_ptr(png_ptr), (byte *)data, length);
  81 }
  82
  83 static void
  84 libpng_flush_fn(png_structp png_ptr UNUSED)
  85 {
  86   DBG("libpng_flush_fn()");
  87 }
  88
  89 static void
  90 libpng_read_cancel(struct image_io *io)
  91 {
  92   DBG("libpng_read_cancel()");
  93
  94   struct libpng_read_data *rd = io->read_data;
  95   png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
  96 }
  97
  98 int
  99 libpng_read_header(struct image_io *io)
 100 {
 101   DBG("libpng_read_header()");
 102
 103   /* Create libpng structures */
 104   struct libpng_read_data *rd = io->read_data = mp_alloc(io->internal_pool, sizeof(*rd));
 105   rd->png_ptr = png_create_read_struct_2(PNG_LIBPNG_VER_STRING,
 106       io->context, libpng_read_error, libpng_warning,
 107       io->internal_pool, libpng_malloc, libpng_free);
 108   if (unlikely(!rd->png_ptr))
 109     {
 110       IMAGE_ERROR(io->context, IMAGE_ERROR_READ_FAILED, "Cannot create libpng read structure.");
 111       return 0;
 112     }
 113   rd->info_ptr = png_create_info_struct(rd->png_ptr);
 114   if (unlikely(!rd->info_ptr))
 115     {
 116       IMAGE_ERROR(io->context, IMAGE_ERROR_READ_FAILED, "Cannot create libpng info structure.");
 117       png_destroy_read_struct(&rd->png_ptr, NULL, NULL);
 118       return 0;
 119     }
 120   rd->end_ptr = png_create_info_struct(rd->png_ptr);
 121   if (unlikely(!rd->end_ptr))
 122     {
 123       IMAGE_ERROR(io->context, IMAGE_ERROR_READ_FAILED, "Cannot create libpng info structure.");
 124       png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, NULL);
 125       return 0;
 126     }
 127
 128   /* Setup libpng longjump */
 129   if (unlikely(setjmp(png_jmpbuf(rd->png_ptr))))
 130     {
 131       DBG("Libpng failed to read the image, longjump saved us");
 132       png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
 133       return 0;
 134     }
 135
 136   /* Setup libpng IO */
 137   png_set_read_fn(rd->png_ptr, io->fastbuf, libpng_read_fn);
 138   png_set_user_limits(rd->png_ptr, image_max_dim, image_max_dim);
 139
 140   /* Read header */
 141   png_read_info(rd->png_ptr, rd->info_ptr);
 142   png_get_IHDR(rd->png_ptr, rd->info_ptr, &rd->cols, &rd->rows, &rd->bit_depth, &rd->color_type, NULL, NULL, NULL);
 143
 144   /* Fill image_io values */
 145   io->cols = rd->cols;
 146   io->rows = rd->rows;
 147   switch (rd->color_type)
 148     {
 149       case PNG_COLOR_TYPE_GRAY:
 150         io->flags = COLOR_SPACE_GRAYSCALE;
 151         io->number_of_colors = 1 << 8;
 152         break;
 153       case PNG_COLOR_TYPE_GRAY_ALPHA:
 154         io->flags = COLOR_SPACE_GRAYSCALE | IMAGE_ALPHA;
 155         io->number_of_colors = 1 << 8;
 156         break;
 157       case PNG_COLOR_TYPE_RGB:
 158         io->flags = COLOR_SPACE_RGB;
 159         io->number_of_colors = 1 << 24;
 160         break;
 161       case PNG_COLOR_TYPE_RGB_ALPHA:
 162         io->number_of_colors = 1 << 24;
 163         io->flags = COLOR_SPACE_RGB | IMAGE_ALPHA;
 164         break;
 165       case PNG_COLOR_TYPE_PALETTE:
 166         io->flags = COLOR_SPACE_RGB | IMAGE_ALPHA | IMAGE_IO_HAS_PALETTE;
 167         int num_palette;
 168         if (png_get_PLTE(rd->png_ptr, rd->info_ptr, NULL, &num_palette))
 169           io->number_of_colors = num_palette;
 170         else
 171           io->number_of_colors = 1 << rd->bit_depth;
 172         break;
 173       default:
 174         png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
 175         IMAGE_ERROR(io->context, IMAGE_ERROR_READ_FAILED, "Unknown color type");
 176         break;
 177     }
 178
 179   /* Success */
 180   io->read_cancel = libpng_read_cancel;
 181   return 1;
 182 }
 183
 184 int
 185 libpng_read_data(struct image_io *io)
 186 {
 187   DBG("libpng_read_data()");
 188
 189   struct libpng_read_data *rd = io->read_data;
 190
 191   struct image_io_read_data_internals rdi;
 192   rdi.image = NULL;
 193
 194   if (setjmp(png_jmpbuf(rd->png_ptr)))
 195     {
 196       DBG("Libpng failed to read the image, longjump saved us");
 197       png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
 198       if (rdi.image)
 199         image_io_read_data_break(&rdi, io);
 200       return 0;
 201     }
 202
 203   uns read_flags = io->flags;
 204
 205   /* Apply transformations */
 206   if (rd->bit_depth == 16)
 207     png_set_strip_16(rd->png_ptr);
 208   switch (rd->color_type)
 209     {
 210       case PNG_COLOR_TYPE_PALETTE:
 211         if ((read_flags & IMAGE_COLOR_SPACE) == COLOR_SPACE_GRAYSCALE)
 212           {
 213             png_set_palette_to_rgb(rd->png_ptr);
 214             png_set_rgb_to_gray_fixed(rd->png_ptr, 1, 21267, 71514);
 215           }
 216         else
 217           {
 218             png_set_palette_to_rgb(rd->png_ptr);
 219             read_flags = (read_flags & ~IMAGE_COLOR_SPACE & IMAGE_CHANNELS_FORMAT) | COLOR_SPACE_RGB;
 220           }
 221         if (!(read_flags & IMAGE_ALPHA))
 222           {
 223             if (io->flags & IMAGE_IO_USE_BACKGROUND)
 224               {
 225                 png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
 226                 read_flags = (read_flags & IMAGE_CHANNELS_FORMAT) | IMAGE_ALPHA;
 227               }
 228             else if ((read_flags & IMAGE_PIXEL_FORMAT) == (COLOR_SPACE_RGB | IMAGE_PIXELS_ALIGNED))
 229               png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
 230             else
 231               png_set_strip_alpha(rd->png_ptr);
 232           }
 233         else
 234           png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
 235         break;
 236       case PNG_COLOR_TYPE_GRAY:
 237         if ((read_flags & IMAGE_COLOR_SPACE) != COLOR_SPACE_GRAYSCALE)
 238           {
 239             png_set_gray_to_rgb(rd->png_ptr);
 240             read_flags = (read_flags & ~IMAGE_COLOR_SPACE & IMAGE_CHANNELS_FORMAT) | COLOR_SPACE_RGB;
 241           }
 242         if (read_flags & IMAGE_ALPHA)
 243           png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
 244         break;
 245       case PNG_COLOR_TYPE_GRAY_ALPHA:
 246         if ((read_flags & IMAGE_COLOR_SPACE) != COLOR_SPACE_GRAYSCALE)
 247           {
 248             png_set_gray_to_rgb(rd->png_ptr);
 249             read_flags = (read_flags & ~IMAGE_COLOR_SPACE & IMAGE_CHANNELS_FORMAT) | COLOR_SPACE_RGB;
 250           }
 251         if (!(read_flags & IMAGE_ALPHA))
 252           {
 253             if (io->flags & IMAGE_IO_USE_BACKGROUND)
 254               read_flags = (read_flags & IMAGE_CHANNELS_FORMAT) | IMAGE_ALPHA;
 255             else
 256               png_set_strip_alpha(rd->png_ptr);
 257           }
 258         break;
 259       case PNG_COLOR_TYPE_RGB:
 260         if ((read_flags & IMAGE_COLOR_SPACE) == COLOR_SPACE_GRAYSCALE)
 261           png_set_rgb_to_gray_fixed(rd->png_ptr, 1, 21267, 71514);
 262         else
 263           read_flags = (read_flags & ~IMAGE_COLOR_SPACE & IMAGE_CHANNELS_FORMAT) | COLOR_SPACE_RGB;
 264         if ((read_flags & IMAGE_ALPHA) || (read_flags & IMAGE_PIXEL_FORMAT) == (COLOR_SPACE_RGB | IMAGE_PIXELS_ALIGNED))
 265           png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
 266         break;
 267       case PNG_COLOR_TYPE_RGB_ALPHA:
 268         if ((read_flags & IMAGE_COLOR_SPACE) == COLOR_SPACE_GRAYSCALE)
 269           png_set_rgb_to_gray_fixed(rd->png_ptr, 1, 21267, 71514);
 270         else
 271           read_flags = (read_flags & ~IMAGE_COLOR_SPACE & IMAGE_CHANNELS_FORMAT) | COLOR_SPACE_RGB;
 272         if (!(read_flags & IMAGE_ALPHA))
 273           if (io->flags & IMAGE_IO_USE_BACKGROUND)
 274             read_flags = (read_flags & IMAGE_CHANNELS_FORMAT) | IMAGE_ALPHA;
 275           else if ((read_flags & IMAGE_PIXEL_FORMAT) != (COLOR_SPACE_RGB | IMAGE_PIXELS_ALIGNED))
 276             png_set_strip_alpha(rd->png_ptr);
 277         break;
 278       default:
 279         ASSERT(0);
 280     }
 281   png_read_update_info(rd->png_ptr, rd->info_ptr);
 282
 283   /* Prepare the image */
 284   if (unlikely(!image_io_read_data_prepare(&rdi, io, rd->cols, rd->rows, read_flags)))
 285     {
 286       png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
 287       return 0;
 288     }
 289   /* Read image data */
 290   DBG("Reading image data");
 291   struct image *img = rdi.image;
 292   byte *pixels = img->pixels;
 293   png_bytep rows[img->rows];
 294   for (uns r = 0; r < img->rows; r++, pixels += img->row_size)
 295     rows[r] = (png_bytep)pixels;
 296   png_read_image(rd->png_ptr, rows);
 297   png_read_end(rd->png_ptr, rd->end_ptr);
 298
 299   /* Destroy libpng read structure */
 300   png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
 301
 302   /* Finish the image  */
 303   return image_io_read_data_finish(&rdi, io);
 304 }
 305
 306 int
 307 libpng_write(struct image_io *io)
 308 {
 309   DBG("libpng_write()");
 310
 311   /* Create libpng structures */
 312   png_structp png_ptr = png_create_write_struct_2(PNG_LIBPNG_VER_STRING,
 313       io->context, libpng_write_error, libpng_warning,
 314       io->internal_pool, libpng_malloc, libpng_free);
 315   if (unlikely(!png_ptr))
 316     {
 317       IMAGE_ERROR(io->context, IMAGE_ERROR_WRITE_FAILED, "Cannot create libpng write structure.");
 318       return 0;
 319     }
 320   png_infop info_ptr = png_create_info_struct(png_ptr);
 321   if (unlikely(!info_ptr))
 322     {
 323       IMAGE_ERROR(io->context, IMAGE_ERROR_WRITE_FAILED, "Cannot create libpng info structure.");
 324       png_destroy_write_struct(&png_ptr, NULL);
 325       return 0;
 326     }
 327
 328   /* Setup libpng longjump */
 329   if (unlikely(setjmp(png_jmpbuf(png_ptr))))
 330     {
 331       DBG("Libpng failed to write the image, longjump saved us.");
 332       png_destroy_write_struct(&png_ptr, &info_ptr);
 333       return 0;
 334     }
 335
 336   /* Setup libpng IO */
 337   png_set_write_fn(png_ptr, io->fastbuf, libpng_write_fn, libpng_flush_fn);
 338
 339   /* Setup PNG parameters */
 340   struct image *img = io->image;
 341   switch (img->flags & IMAGE_PIXEL_FORMAT)
 342     {
 343       case COLOR_SPACE_GRAYSCALE | IMAGE_PIXELS_ALIGNED:
 344         png_set_IHDR(png_ptr, info_ptr, img->cols, img->rows, 8, PNG_COLOR_TYPE_GRAY,
 345           PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
 346         break;
 347       case COLOR_SPACE_GRAYSCALE | IMAGE_ALPHA | IMAGE_PIXELS_ALIGNED:
 348         png_set_IHDR(png_ptr, info_ptr, img->cols, img->rows, 8, PNG_COLOR_TYPE_GRAY_ALPHA,
 349           PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
 350         break;
 351       case COLOR_SPACE_RGB:
 352         png_set_IHDR(png_ptr, info_ptr, img->cols, img->rows, 8, PNG_COLOR_TYPE_RGB,
 353           PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
 354         break;
 355       case COLOR_SPACE_RGB | IMAGE_ALPHA | IMAGE_PIXELS_ALIGNED:
 356         png_set_IHDR(png_ptr, info_ptr, img->cols, img->rows, 8, PNG_COLOR_TYPE_RGB_ALPHA,
 357           PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
 358         break;
 359       case COLOR_SPACE_RGB | IMAGE_PIXELS_ALIGNED:
 360         png_set_IHDR(png_ptr, info_ptr, img->cols, img->rows, 8, PNG_COLOR_TYPE_RGB,
 361           PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
 362         png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
 363         break;
 364       default:
 365         IMAGE_ERROR(io->context, IMAGE_ERROR_WRITE_FAILED, "Libpng does not support this pixel format (0x%x)", img->flags & IMAGE_PIXEL_FORMAT);
 366         png_destroy_write_struct(&png_ptr, &info_ptr);
 367         return 0;
 368     }
 369   png_write_info(png_ptr, info_ptr);
 370
 371   /* Write pixels */
 372   byte *pixels = img->pixels;
 373   png_bytep rows[img->rows];
 374   for (uns r = 0; r < img->rows; r++, pixels += img->row_size)
 375     rows[r] = (png_bytep)pixels;
 376   png_write_image(png_ptr, rows);
 377   png_write_end(png_ptr, info_ptr);
 378
 379   /* Free libpng structure */
 380   png_destroy_write_struct(&png_ptr, &info_ptr);
 381   return 1;
 382 }