/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*- */ /* GdkPixbuf library - PNG image loader * * Copyright (C) 1999 Mark Crichton * Copyright (C) 1999 The Free Software Foundation * * Authors: Mark Crichton * Federico Mena-Quintero * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ #include #include #include #include #include "gdk-pixbuf-private.h" #include "gdk-pixbuf-io.h" static void setup_png_transformations(png_structp png_read_ptr, png_infop png_info_ptr, gboolean *fatal_error_occurred, png_uint_32* width_p, png_uint_32* height_p, int* color_type_p) { png_uint_32 width, height; int bit_depth, color_type, interlace_type, compression_type, filter_type; int channels; /* Get the image info */ png_get_IHDR (png_read_ptr, png_info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, &compression_type, &filter_type); /* set_expand() basically needs to be called unless we are already in RGB/RGBA mode */ if (color_type == PNG_COLOR_TYPE_PALETTE && bit_depth <= 8) { /* Convert indexed images to RGB */ png_set_expand (png_read_ptr); } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) { /* Convert grayscale to RGB */ png_set_expand (png_read_ptr); } else if (png_get_valid (png_read_ptr, png_info_ptr, PNG_INFO_tRNS)) { /* If we have transparency header, convert it to alpha channel */ png_set_expand(png_read_ptr); } else if (bit_depth < 8) { /* If we have < 8 scale it up to 8 */ png_set_expand(png_read_ptr); /* Conceivably, png_set_packing() is a better idea; * God only knows how libpng works */ } /* If we are 16-bit, convert to 8-bit */ if (bit_depth == 16) { png_set_strip_16(png_read_ptr); } /* If gray scale, convert to RGB */ if (color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_GRAY_ALPHA) { png_set_gray_to_rgb(png_read_ptr); } /* If interlaced, handle that */ if (interlace_type != PNG_INTERLACE_NONE) { png_set_interlace_handling(png_read_ptr); } /* Update the info the reflect our transformations */ png_read_update_info(png_read_ptr, png_info_ptr); png_get_IHDR (png_read_ptr, png_info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, &compression_type, &filter_type); *width_p = width; *height_p = height; *color_type_p = color_type; #ifndef G_DISABLE_CHECKS /* Check that the new info is what we want */ if (bit_depth != 8) { g_warning("Bits per channel of transformed PNG is %d, not 8.", bit_depth); *fatal_error_occurred = TRUE; return; } if ( ! (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA) ) { g_warning("Transformed PNG not RGB or RGBA."); *fatal_error_occurred = TRUE; return; } channels = png_get_channels(png_read_ptr, png_info_ptr); if ( ! (channels == 3 || channels == 4) ) { g_warning("Transformed PNG has %d channels, must be 3 or 4.", channels); *fatal_error_occurred = TRUE; return; } #endif } static void png_simple_error_callback(png_structp png_save_ptr, png_const_charp error_msg) { GError **error; error = png_get_error_ptr(png_save_ptr); /* I don't trust libpng to call the error callback only once, * so check for already-set error */ if (error && *error == NULL) { g_set_error (error, GDK_PIXBUF_ERROR, GDK_PIXBUF_ERROR_FAILED, _("Fatal error in PNG image file: %s"), error_msg); } } static void png_simple_warning_callback(png_structp png_save_ptr, png_const_charp warning_msg) { /* Don't print anything; we should not be dumping junk to * stderr, since that may be bad for some apps. If it's * important enough to display, we need to add a GError * **warning return location wherever we have an error return * location. */ } /* Destroy notification function for the pixbuf */ static void free_buffer (guchar *pixels, gpointer data) { g_free (pixels); } /* Shared library entry point */ static GdkPixbuf * gdk_pixbuf__png_image_load (FILE *f, GError **error) { png_structp png_ptr; png_infop info_ptr, end_info; gboolean failed = FALSE; gint i, ctype, bpp; png_uint_32 w, h; png_bytepp rows; guchar *pixels; png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING, error, png_simple_error_callback, png_simple_warning_callback); if (!png_ptr) return NULL; info_ptr = png_create_info_struct (png_ptr); if (!info_ptr) { png_destroy_read_struct (&png_ptr, NULL, NULL); return NULL; } end_info = png_create_info_struct (png_ptr); if (!end_info) { png_destroy_read_struct (&png_ptr, &info_ptr, NULL); return NULL; } if (setjmp (png_ptr->jmpbuf)) { png_destroy_read_struct (&png_ptr, &info_ptr, &end_info); return NULL; } png_init_io (png_ptr, f); png_read_info (png_ptr, info_ptr); setup_png_transformations(png_ptr, info_ptr, &failed, &w, &h, &ctype); if (failed) { png_destroy_read_struct (&png_ptr, &info_ptr, &end_info); return NULL; } if (ctype & PNG_COLOR_MASK_ALPHA) bpp = 4; else bpp = 3; pixels = g_try_malloc (w * h * bpp); if (!pixels) { /* Check error NULL, normally this would be broken, * but libpng makes me want to code defensively. */ if (error && *error == NULL) { g_set_error (error, GDK_PIXBUF_ERROR, GDK_PIXBUF_ERROR_INSUFFICIENT_MEMORY, _("Insufficient memory to load PNG file")); } png_destroy_read_struct (&png_ptr, &info_ptr, &end_info); return NULL; } rows = g_new (png_bytep, h); for (i = 0; i < h; i++) rows[i] = pixels + i * w * bpp; png_read_image (png_ptr, rows); png_destroy_read_struct (&png_ptr, &info_ptr, &end_info); g_free (rows); if (ctype & PNG_COLOR_MASK_ALPHA) return gdk_pixbuf_new_from_data (pixels, GDK_COLORSPACE_RGB, TRUE, 8, w, h, w * 4, free_buffer, NULL); else return gdk_pixbuf_new_from_data (pixels, GDK_COLORSPACE_RGB, FALSE, 8, w, h, w * 3, free_buffer, NULL); } /* I wish these avoided the setjmp()/longjmp() crap in libpng instead just allow you to change the error reporting. */ static void png_error_callback (png_structp png_read_ptr, png_const_charp error_msg); static void png_warning_callback(png_structp png_read_ptr, png_const_charp warning_msg); /* Called at the start of the progressive load */ static void png_info_callback (png_structp png_read_ptr, png_infop png_info_ptr); /* Called for each row; note that you will get duplicate row numbers for interlaced PNGs */ static void png_row_callback (png_structp png_read_ptr, png_bytep new_row, png_uint_32 row_num, int pass_num); /* Called after reading the entire image */ static void png_end_callback (png_structp png_read_ptr, png_infop png_info_ptr); typedef struct _LoadContext LoadContext; struct _LoadContext { png_structp png_read_ptr; png_infop png_info_ptr; ModulePreparedNotifyFunc prepare_func; ModuleUpdatedNotifyFunc update_func; gpointer notify_user_data; GdkPixbuf* pixbuf; /* row number of first row seen, or -1 if none yet seen */ gint first_row_seen_in_chunk; /* pass number for the first row seen */ gint first_pass_seen_in_chunk; /* row number of last row seen */ gint last_row_seen_in_chunk; gint last_pass_seen_in_chunk; /* highest row number seen */ gint max_row_seen_in_chunk; guint fatal_error_occurred : 1; GError **error; }; static gpointer gdk_pixbuf__png_image_begin_load (ModulePreparedNotifyFunc prepare_func, ModuleUpdatedNotifyFunc update_func, gpointer user_data, GError **error) { LoadContext* lc; lc = g_new0(LoadContext, 1); lc->fatal_error_occurred = FALSE; lc->prepare_func = prepare_func; lc->update_func = update_func; lc->notify_user_data = user_data; lc->first_row_seen_in_chunk = -1; lc->last_row_seen_in_chunk = -1; lc->first_pass_seen_in_chunk = -1; lc->last_pass_seen_in_chunk = -1; lc->max_row_seen_in_chunk = -1; lc->error = error; /* Create the main PNG context struct */ lc->png_read_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, lc, /* error/warning callback data */ png_error_callback, png_warning_callback); if (lc->png_read_ptr == NULL) { g_free(lc); /* error callback should have set the error */ return NULL; } if (setjmp (lc->png_read_ptr->jmpbuf)) { if (lc->png_info_ptr) png_destroy_read_struct(&lc->png_read_ptr, NULL, NULL); g_free(lc); /* error callback should have set the error */ return NULL; } /* Create the auxiliary context struct */ lc->png_info_ptr = png_create_info_struct(lc->png_read_ptr); if (lc->png_info_ptr == NULL) { png_destroy_read_struct(&lc->png_read_ptr, NULL, NULL); g_free(lc); /* error callback should have set the error */ return NULL; } png_set_progressive_read_fn(lc->png_read_ptr, lc, /* callback data */ png_info_callback, png_row_callback, png_end_callback); /* We don't want to keep modifying error after returning here, * it may no longer be valid. */ lc->error = NULL; return lc; } static gboolean gdk_pixbuf__png_image_stop_load (gpointer context, GError **error) { LoadContext* lc = context; g_return_val_if_fail(lc != NULL, TRUE); /* FIXME this thing needs to report errors if * we have unused image data */ if (lc->pixbuf) gdk_pixbuf_unref (lc->pixbuf); png_destroy_read_struct(&lc->png_read_ptr, NULL, NULL); g_free(lc); return TRUE; } static gboolean gdk_pixbuf__png_image_load_increment(gpointer context, const guchar *buf, guint size, GError **error) { LoadContext* lc = context; g_return_val_if_fail(lc != NULL, FALSE); /* reset */ lc->first_row_seen_in_chunk = -1; lc->last_row_seen_in_chunk = -1; lc->first_pass_seen_in_chunk = -1; lc->last_pass_seen_in_chunk = -1; lc->max_row_seen_in_chunk = -1; lc->error = error; /* Invokes our callbacks as needed */ if (setjmp (lc->png_read_ptr->jmpbuf)) { lc->error = NULL; return FALSE; } else { png_process_data(lc->png_read_ptr, lc->png_info_ptr, (guchar*) buf, size); } if (lc->fatal_error_occurred) { lc->error = NULL; return FALSE; } else { if (lc->first_row_seen_in_chunk >= 0) { /* We saw at least one row */ gint pass_diff = lc->last_pass_seen_in_chunk - lc->first_pass_seen_in_chunk; g_assert(pass_diff >= 0); if (pass_diff == 0) { /* start and end row were in the same pass */ (lc->update_func)(lc->pixbuf, 0, lc->first_row_seen_in_chunk, lc->pixbuf->width, (lc->last_row_seen_in_chunk - lc->first_row_seen_in_chunk) + 1, lc->notify_user_data); } else if (pass_diff == 1) { /* We have from the first row seen to the end of the image (max row seen), then from the top of the image to the last row seen */ /* first row to end */ (lc->update_func)(lc->pixbuf, 0, lc->first_row_seen_in_chunk, lc->pixbuf->width, (lc->max_row_seen_in_chunk - lc->first_row_seen_in_chunk) + 1, lc->notify_user_data); /* top to last row */ (lc->update_func)(lc->pixbuf, 0, 0, lc->pixbuf->width, lc->last_row_seen_in_chunk + 1, lc->notify_user_data); } else { /* We made at least one entire pass, so update the whole image */ (lc->update_func)(lc->pixbuf, 0, 0, lc->pixbuf->width, lc->max_row_seen_in_chunk + 1, lc->notify_user_data); } } lc->error = NULL; return TRUE; } } /* Called at the start of the progressive load, once we have image info */ static void png_info_callback (png_structp png_read_ptr, png_infop png_info_ptr) { LoadContext* lc; png_uint_32 width, height; int color_type; gboolean have_alpha = FALSE; gboolean failed = FALSE; lc = png_get_progressive_ptr(png_read_ptr); if (lc->fatal_error_occurred) return; setup_png_transformations(lc->png_read_ptr, lc->png_info_ptr, &failed, &width, &height, &color_type); if (failed) { lc->fatal_error_occurred = TRUE; return; } /* If we have alpha, set a flag */ if (color_type & PNG_COLOR_MASK_ALPHA) have_alpha = TRUE; lc->pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, have_alpha, 8, width, height); if (lc->pixbuf == NULL) { /* Failed to allocate memory */ lc->fatal_error_occurred = TRUE; if (lc->error && *lc->error == NULL) { g_set_error (lc->error, GDK_PIXBUF_ERROR, GDK_PIXBUF_ERROR_INSUFFICIENT_MEMORY, _("Insufficient memory to store a %ld by %ld image; try exiting some applications to reduce memory usage"), width, height); } return; } /* Notify the client that we are ready to go */ if (lc->prepare_func) (* lc->prepare_func) (lc->pixbuf, NULL, lc->notify_user_data); return; } /* Called for each row; note that you will get duplicate row numbers for interlaced PNGs */ static void png_row_callback (png_structp png_read_ptr, png_bytep new_row, png_uint_32 row_num, int pass_num) { LoadContext* lc; guchar* old_row = NULL; lc = png_get_progressive_ptr(png_read_ptr); if (lc->fatal_error_occurred) return; if (lc->first_row_seen_in_chunk < 0) { lc->first_row_seen_in_chunk = row_num; lc->first_pass_seen_in_chunk = pass_num; } lc->max_row_seen_in_chunk = MAX(lc->max_row_seen_in_chunk, ((gint)row_num)); lc->last_row_seen_in_chunk = row_num; lc->last_pass_seen_in_chunk = pass_num; old_row = lc->pixbuf->pixels + (row_num * lc->pixbuf->rowstride); png_progressive_combine_row(lc->png_read_ptr, old_row, new_row); } /* Called after reading the entire image */ static void png_end_callback (png_structp png_read_ptr, png_infop png_info_ptr) { LoadContext* lc; lc = png_get_progressive_ptr(png_read_ptr); if (lc->fatal_error_occurred) return; } static void png_error_callback(png_structp png_read_ptr, png_const_charp error_msg) { LoadContext* lc; lc = png_get_error_ptr(png_read_ptr); lc->fatal_error_occurred = TRUE; /* I don't trust libpng to call the error callback only once, * so check for already-set error */ if (lc->error && *lc->error == NULL) { g_set_error (lc->error, GDK_PIXBUF_ERROR, GDK_PIXBUF_ERROR_CORRUPT_IMAGE, _("Fatal error reading PNG image file: %s"), error_msg); } longjmp (png_read_ptr->jmpbuf, 1); } static void png_warning_callback(png_structp png_read_ptr, png_const_charp warning_msg) { LoadContext* lc; lc = png_get_error_ptr(png_read_ptr); /* Don't print anything; we should not be dumping junk to * stderr, since that may be bad for some apps. If it's * important enough to display, we need to add a GError * **warning return location wherever we have an error return * location. */ } /* Save */ static gboolean gdk_pixbuf__png_image_save (FILE *f, GdkPixbuf *pixbuf, gchar **keys, gchar **values, GError **error) { png_structp png_ptr; png_infop info_ptr; guchar *ptr; guchar *pixels; int x, y, j; png_bytep row_ptr; png_bytep data; png_color_8 sig_bit; int w, h, rowstride; int has_alpha; int bpc; if (keys && *keys) { g_warning ("Bad option name '%s' passed to PNG saver", *keys); return FALSE; #if 0 gchar **kiter = keys; gchar **viter = values; while (*kiter) { ++kiter; ++viter; } #endif } data = NULL; bpc = gdk_pixbuf_get_bits_per_sample (pixbuf); w = gdk_pixbuf_get_width (pixbuf); h = gdk_pixbuf_get_height (pixbuf); rowstride = gdk_pixbuf_get_rowstride (pixbuf); has_alpha = gdk_pixbuf_get_has_alpha (pixbuf); pixels = gdk_pixbuf_get_pixels (pixbuf); png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, error, png_simple_error_callback, png_simple_warning_callback); g_return_val_if_fail (png_ptr != NULL, FALSE); info_ptr = png_create_info_struct (png_ptr); if (info_ptr == NULL) { png_destroy_write_struct (&png_ptr, (png_infopp) NULL); return FALSE; } if (setjmp (png_ptr->jmpbuf)) { png_destroy_write_struct (&png_ptr, (png_infopp) NULL); return FALSE; } png_init_io (png_ptr, f); if (has_alpha) { png_set_IHDR (png_ptr, info_ptr, w, h, bpc, PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); #ifdef WORDS_BIGENDIAN png_set_swap_alpha (png_ptr); #else png_set_bgr (png_ptr); #endif } else { png_set_IHDR (png_ptr, info_ptr, w, h, bpc, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); data = g_try_malloc (w * 3 * sizeof (char)); if (data == NULL) { /* Check error NULL, normally this would be broken, * but libpng makes me want to code defensively. */ if (error && *error == NULL) { g_set_error (error, GDK_PIXBUF_ERROR, GDK_PIXBUF_ERROR_INSUFFICIENT_MEMORY, _("Insufficient memory to save PNG file")); } png_destroy_write_struct (&png_ptr, (png_infopp) NULL); return FALSE; } } sig_bit.red = bpc; sig_bit.green = bpc; sig_bit.blue = bpc; sig_bit.alpha = bpc; png_set_sBIT (png_ptr, info_ptr, &sig_bit); png_write_info (png_ptr, info_ptr); png_set_shift (png_ptr, &sig_bit); png_set_packing (png_ptr); ptr = pixels; for (y = 0; y < h; y++) { if (has_alpha) row_ptr = (png_bytep)ptr; else { for (j = 0, x = 0; x < w; x++) memcpy (&(data[x*3]), &(ptr[x*3]), 3); row_ptr = (png_bytep)data; } png_write_rows (png_ptr, &row_ptr, 1); ptr += rowstride; } if (data) g_free (data); png_write_end (png_ptr, info_ptr); png_destroy_write_struct (&png_ptr, (png_infopp) NULL); return TRUE; } void gdk_pixbuf__png_fill_vtable (GdkPixbufModule *module) { module->load = gdk_pixbuf__png_image_load; module->begin_load = gdk_pixbuf__png_image_begin_load; module->stop_load = gdk_pixbuf__png_image_stop_load; module->load_increment = gdk_pixbuf__png_image_load_increment; module->save = gdk_pixbuf__png_image_save; }