2 * Image Library -- libpng
4 * (c) 2006 Pavel Charvat <pchar@ucw.cz>
6 * This software may be freely distributed and used according to the terms
7 * of the GNU Lesser General Public License.
13 #include "lib/mempool.h"
14 #include "lib/fastbuf.h"
15 #include "images/images.h"
16 #include "images/io-main.h"
20 struct libpng_read_data {
31 libpng_malloc(png_structp png_ptr, png_size_t size)
33 DBG("libpng_malloc(size=%u)", (uns)size);
34 return mp_alloc(png_get_mem_ptr(png_ptr), size);
38 libpng_free(png_structp png_ptr UNUSED, png_voidp ptr UNUSED)
44 libpng_read_error(png_structp png_ptr, png_const_charp msg)
46 DBG("libpng_read_error()");
47 image_thread_err_dup(png_get_error_ptr(png_ptr), IMAGE_ERR_READ_FAILED, (byte *)msg);
48 longjmp(png_jmpbuf(png_ptr), 1);
52 libpng_write_error(png_structp png_ptr, png_const_charp msg)
54 DBG("libpng_write_error()");
55 image_thread_err_dup(png_get_error_ptr(png_ptr), IMAGE_ERR_WRITE_FAILED, (byte *)msg);
56 longjmp(png_jmpbuf(png_ptr), 1);
60 libpng_warning(png_structp png_ptr UNUSED, png_const_charp msg UNUSED)
62 DBG("libpng_warning(): %s", (byte *)msg);
66 libpng_read_fn(png_structp png_ptr, png_bytep data, png_size_t length)
68 DBG("libpng_read_fn(len=%u)", (uns)length);
69 if (unlikely(bread((struct fastbuf *)png_get_io_ptr(png_ptr), (byte *)data, length) < length))
70 png_error(png_ptr, "Incomplete data");
74 libpng_write_fn(png_structp png_ptr, png_bytep data, png_size_t length)
76 DBG("libpng_write_fn(len=%u)", (uns)length);
77 bwrite((struct fastbuf *)png_get_io_ptr(png_ptr), (byte *)data, length);
81 libpng_flush_fn(png_structp png_ptr UNUSED)
83 DBG("libpng_flush_fn()");
87 libpng_read_cancel(struct image_io *io)
89 DBG("libpng_read_cancel()");
91 struct libpng_read_data *rd = io->read_data;
92 png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
96 libpng_read_header(struct image_io *io)
98 DBG("libpng_read_header()");
100 /* Create libpng structures */
101 struct libpng_read_data *rd = io->read_data = mp_alloc(io->internal_pool, sizeof(*rd));
102 rd->png_ptr = png_create_read_struct_2(PNG_LIBPNG_VER_STRING,
103 io->thread, libpng_read_error, libpng_warning,
104 io->internal_pool, libpng_malloc, libpng_free);
105 if (unlikely(!rd->png_ptr))
107 image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "Cannot create libpng read structure.");
110 rd->info_ptr = png_create_info_struct(rd->png_ptr);
111 if (unlikely(!rd->info_ptr))
113 image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "Cannot create libpng info structure.");
114 png_destroy_read_struct(&rd->png_ptr, NULL, NULL);
117 rd->end_ptr = png_create_info_struct(rd->png_ptr);
118 if (unlikely(!rd->end_ptr))
120 image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "Cannot create libpng info structure.");
121 png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, NULL);
125 /* Setup libpng longjump */
126 if (unlikely(setjmp(png_jmpbuf(rd->png_ptr))))
128 DBG("Libpng failed to read the image, longjump saved us");
129 png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
133 /* Setup libpng IO */
134 png_set_read_fn(rd->png_ptr, io->fastbuf, libpng_read_fn);
135 png_set_user_limits(rd->png_ptr, IMAGE_MAX_SIZE, IMAGE_MAX_SIZE);
138 png_read_info(rd->png_ptr, rd->info_ptr);
139 png_get_IHDR(rd->png_ptr, rd->info_ptr, &rd->cols, &rd->rows, &rd->bit_depth, &rd->color_type, NULL, NULL, NULL);
141 /* Fill image_io values */
144 switch (rd->color_type)
146 case PNG_COLOR_TYPE_GRAY:
147 io->flags = COLOR_SPACE_GRAYSCALE;
148 io->number_of_colors = 1 << 8;
150 case PNG_COLOR_TYPE_GRAY_ALPHA:
151 io->flags = COLOR_SPACE_GRAYSCALE | IMAGE_ALPHA;
152 io->number_of_colors = 1 << 8;
154 case PNG_COLOR_TYPE_RGB:
155 io->flags = COLOR_SPACE_RGB;
156 io->number_of_colors = 1 << 24;
158 case PNG_COLOR_TYPE_RGB_ALPHA:
159 io->number_of_colors = 1 << 24;
160 io->flags = COLOR_SPACE_RGB | IMAGE_ALPHA;
162 case PNG_COLOR_TYPE_PALETTE:
163 io->flags = COLOR_SPACE_RGB | IMAGE_ALPHA | IMAGE_IO_HAS_PALETTE;
165 if (png_get_PLTE(rd->png_ptr, rd->info_ptr, NULL, &num_palette))
166 io->number_of_colors = num_palette;
168 io->number_of_colors = 1 << rd->bit_depth;
171 png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
172 image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "Unknown color type");
177 io->read_cancel = libpng_read_cancel;
182 libpng_read_data(struct image_io *io)
184 DBG("libpng_read_data()");
186 struct libpng_read_data *rd = io->read_data;
188 /* Test supported pixel formats */
189 switch (io->flags & IMAGE_COLOR_SPACE)
191 case COLOR_SPACE_GRAYSCALE:
192 case COLOR_SPACE_RGB:
195 png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
196 image_thread_err(io->thread, IMAGE_ERR_INVALID_PIXEL_FORMAT, "Unsupported color space.");
200 /* Prepare the image */
201 struct image_io_read_data_internals rdi;
202 if (unlikely(!image_io_read_data_prepare(&rdi, io, rd->cols, rd->rows)))
204 png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
208 if (setjmp(png_jmpbuf(rd->png_ptr)))
210 DBG("Libpng failed to read the image, longjump saved us");
211 png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
212 image_io_read_data_break(&rdi, io);
216 /* Apply transformations */
217 if (rd->bit_depth == 16)
218 png_set_strip_16(rd->png_ptr);
219 switch (rd->color_type)
221 case PNG_COLOR_TYPE_PALETTE:
222 if ((io->flags & IMAGE_COLOR_SPACE) == COLOR_SPACE_GRAYSCALE)
224 png_set_palette_to_rgb(rd->png_ptr);
225 png_set_rgb_to_gray_fixed(rd->png_ptr, 1, 21267, 71514);
228 png_set_palette_to_rgb(rd->png_ptr);
229 if ((io->flags & IMAGE_ALPHA) || (io->flags & IMAGE_PIXEL_FORMAT) == (COLOR_SPACE_RGB | IMAGE_PIXELS_ALIGNED))
230 png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
232 png_set_strip_alpha(rd->png_ptr);
234 case PNG_COLOR_TYPE_GRAY:
235 if ((io->flags & IMAGE_COLOR_SPACE) == COLOR_SPACE_RGB)
236 png_set_gray_to_rgb(rd->png_ptr);
237 if (io->flags & IMAGE_ALPHA)
238 png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
240 case PNG_COLOR_TYPE_GRAY_ALPHA:
241 if ((io->flags & IMAGE_COLOR_SPACE) == COLOR_SPACE_RGB)
242 png_set_gray_to_rgb(rd->png_ptr);
243 if (!(io->flags & IMAGE_ALPHA))
244 png_set_strip_alpha(rd->png_ptr);
246 case PNG_COLOR_TYPE_RGB:
247 if ((io->flags & IMAGE_COLOR_SPACE) == COLOR_SPACE_GRAYSCALE)
248 png_set_rgb_to_gray_fixed(rd->png_ptr, 1, 21267, 71514);
249 if ((io->flags & IMAGE_ALPHA) || (io->flags & IMAGE_PIXEL_FORMAT) == (COLOR_SPACE_RGB | IMAGE_PIXELS_ALIGNED))
250 png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
252 case PNG_COLOR_TYPE_RGB_ALPHA:
253 if ((io->flags & IMAGE_COLOR_SPACE) == COLOR_SPACE_GRAYSCALE)
254 png_set_rgb_to_gray_fixed(rd->png_ptr, 1, 21267, 71514);
255 if (!(io->flags & IMAGE_ALPHA) && (io->flags & IMAGE_PIXEL_FORMAT) != (COLOR_SPACE_RGB | IMAGE_PIXELS_ALIGNED))
256 png_set_strip_alpha(rd->png_ptr);
261 png_read_update_info(rd->png_ptr, rd->info_ptr);
263 /* Read image data */
264 DBG("Reading image data");
265 struct image *img = rdi.image;
266 byte *pixels = img->pixels;
267 png_bytep rows[img->rows];
268 for (uns r = 0; r < img->rows; r++, pixels += img->row_size)
269 rows[r] = (png_bytep)pixels;
270 png_read_image(rd->png_ptr, rows);
271 png_read_end(rd->png_ptr, rd->end_ptr);
273 /* Destroy libpng read structure */
274 png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
276 /* Finish the image */
277 return image_io_read_data_finish(&rdi, io);
281 libpng_write(struct image_io *io)
283 DBG("libpng_write()");
285 /* Create libpng structures */
286 png_structp png_ptr = png_create_write_struct_2(PNG_LIBPNG_VER_STRING,
287 io->thread, libpng_write_error, libpng_warning,
288 io->internal_pool, libpng_malloc, libpng_free);
289 if (unlikely(!png_ptr))
291 image_thread_err(io->thread, IMAGE_ERR_WRITE_FAILED, "Cannot create libpng write structure.");
294 png_infop info_ptr = png_create_info_struct(png_ptr);
295 if (unlikely(!info_ptr))
297 image_thread_err(io->thread, IMAGE_ERR_WRITE_FAILED, "Cannot create libpng info structure.");
298 png_destroy_write_struct(&png_ptr, NULL);
302 /* Setup libpng longjump */
303 if (unlikely(setjmp(png_jmpbuf(png_ptr))))
305 DBG("Libpng failed to write the image, longjump saved us.");
306 png_destroy_write_struct(&png_ptr, &info_ptr);
310 /* Setup libpng IO */
311 png_set_write_fn(png_ptr, io->fastbuf, libpng_write_fn, libpng_flush_fn);
313 /* Setup PNG parameters */
314 struct image *img = io->image;
315 switch (img->flags & IMAGE_PIXEL_FORMAT)
317 case COLOR_SPACE_GRAYSCALE | IMAGE_PIXELS_ALIGNED:
318 png_set_IHDR(png_ptr, info_ptr, img->cols, img->rows, 8, PNG_COLOR_TYPE_GRAY,
319 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
321 case COLOR_SPACE_GRAYSCALE | IMAGE_ALPHA | IMAGE_PIXELS_ALIGNED:
322 png_set_IHDR(png_ptr, info_ptr, img->cols, img->rows, 8, PNG_COLOR_TYPE_GRAY_ALPHA,
323 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
325 case COLOR_SPACE_RGB:
326 png_set_IHDR(png_ptr, info_ptr, img->cols, img->rows, 8, PNG_COLOR_TYPE_RGB,
327 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
329 case COLOR_SPACE_RGB | IMAGE_ALPHA | IMAGE_PIXELS_ALIGNED:
330 png_set_IHDR(png_ptr, info_ptr, img->cols, img->rows, 8, PNG_COLOR_TYPE_RGB_ALPHA,
331 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
333 case COLOR_SPACE_RGB | IMAGE_PIXELS_ALIGNED:
334 png_set_IHDR(png_ptr, info_ptr, img->cols, img->rows, 8, PNG_COLOR_TYPE_RGB,
335 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
336 png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
341 png_write_info(png_ptr, info_ptr);
344 byte *pixels = img->pixels;
345 png_bytep rows[img->rows];
346 for (uns r = 0; r < img->rows; r++, pixels += img->row_size)
347 rows[r] = (png_bytep)pixels;
348 png_write_image(png_ptr, rows);
349 png_write_end(png_ptr, info_ptr);
351 /* Free libpng structure */
352 png_destroy_write_struct(&png_ptr, &info_ptr);