Mercurial > hg > forks > geeqie
view src/image_load_jpeg.c @ 1901:d21859e612de
added custom jpeg loader
author | Vladimir Nadvornik <nadvornik@suse.cz> |
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date | Sat, 26 Mar 2011 22:03:30 +0100 |
parents | |
children | 5ae882c45657 |
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#include "main.h" #include "image-load.h" #include "image_load_jpeg.h" #include <setjmp.h> #include <jpeglib.h> #include <jerror.h> typedef struct _ImageLoaderJpeg ImageLoaderJpeg; struct _ImageLoaderJpeg { ImageLoaderBackendCbAreaUpdated area_updated_cb; ImageLoaderBackendCbSize size_cb; ImageLoaderBackendCbAreaPrepared area_prepared_cb; gpointer data; GdkPixbuf *pixbuf; guint requested_width; guint requested_height; gboolean abort; }; /* error handler data */ struct error_handler_data { struct jpeg_error_mgr pub; sigjmp_buf setjmp_buffer; GError **error; }; /* explode gray image data from jpeg library into rgb components in pixbuf */ static void explode_gray_into_buf (struct jpeg_decompress_struct *cinfo, guchar **lines) { gint i, j; guint w; g_return_if_fail (cinfo != NULL); g_return_if_fail (cinfo->output_components == 1); g_return_if_fail (cinfo->out_color_space == JCS_GRAYSCALE); /* Expand grey->colour. Expand from the end of the * memory down, so we can use the same buffer. */ w = cinfo->output_width; for (i = cinfo->rec_outbuf_height - 1; i >= 0; i--) { guchar *from, *to; from = lines[i] + w - 1; to = lines[i] + (w - 1) * 3; for (j = w - 1; j >= 0; j--) { to[0] = from[0]; to[1] = from[0]; to[2] = from[0]; to -= 3; from--; } } } static void convert_cmyk_to_rgb (struct jpeg_decompress_struct *cinfo, guchar **lines) { gint i, j; g_return_if_fail (cinfo != NULL); g_return_if_fail (cinfo->output_components == 4); g_return_if_fail (cinfo->out_color_space == JCS_CMYK); for (i = cinfo->rec_outbuf_height - 1; i >= 0; i--) { guchar *p; p = lines[i]; for (j = 0; j < cinfo->output_width; j++) { int c, m, y, k; c = p[0]; m = p[1]; y = p[2]; k = p[3]; if (cinfo->saw_Adobe_marker) { p[0] = k*c / 255; p[1] = k*m / 255; p[2] = k*y / 255; } else { p[0] = (255 - k)*(255 - c) / 255; p[1] = (255 - k)*(255 - m) / 255; p[2] = (255 - k)*(255 - y) / 255; } p[3] = 255; p += 4; } } } static gpointer image_loader_jpeg_new(ImageLoaderBackendCbAreaUpdated area_updated_cb, ImageLoaderBackendCbSize size_cb, ImageLoaderBackendCbAreaPrepared area_prepared_cb, gpointer data) { ImageLoaderJpeg *loader = g_new0(ImageLoaderJpeg, 1); loader->area_updated_cb = area_updated_cb; loader->size_cb = size_cb; loader->area_prepared_cb = area_prepared_cb; loader->data = data; return (gpointer) loader; } static void fatal_error_handler (j_common_ptr cinfo) { struct error_handler_data *errmgr; char buffer[JMSG_LENGTH_MAX]; errmgr = (struct error_handler_data *) cinfo->err; /* Create the message */ (* cinfo->err->format_message) (cinfo, buffer); /* broken check for *error == NULL for robustness against * crappy JPEG library */ if (errmgr->error && *errmgr->error == NULL) { g_set_error (errmgr->error, GDK_PIXBUF_ERROR, cinfo->err->msg_code == JERR_OUT_OF_MEMORY ? GDK_PIXBUF_ERROR_INSUFFICIENT_MEMORY : GDK_PIXBUF_ERROR_CORRUPT_IMAGE, _("Error interpreting JPEG image file (%s)"), buffer); } siglongjmp (errmgr->setjmp_buffer, 1); g_assert_not_reached (); } static void output_message_handler (j_common_ptr cinfo) { /* This method keeps libjpeg from dumping crap to stderr */ /* do nothing */ } static gboolean image_loader_jpeg_load (gpointer loader, const guchar *buf, gsize count, GError **error) { ImageLoaderJpeg *lj = (ImageLoaderJpeg *) loader; struct jpeg_decompress_struct cinfo; guchar *dptr; guint rowstride; struct error_handler_data jerr; // stdio_src_ptr src; /* setup error handler */ cinfo.err = jpeg_std_error (&jerr.pub); jerr.pub.error_exit = fatal_error_handler; jerr.pub.output_message = output_message_handler; jerr.error = error; if (setjmp(jerr.setjmp_buffer)) { /* If we get here, the JPEG code has signaled an error. * We need to clean up the JPEG object, close the input file, and return. */ jpeg_destroy_decompress(&cinfo); return FALSE; } jpeg_create_decompress(&cinfo); jpeg_mem_src(&cinfo, (unsigned char *)buf, count); jpeg_read_header(&cinfo, TRUE); lj->requested_width = cinfo.image_width; lj->requested_height = cinfo.image_height; lj->size_cb(loader, cinfo.image_width, cinfo.image_height, lj->data); cinfo.scale_num = 1; for (cinfo.scale_denom = 2; cinfo.scale_denom <= 8; cinfo.scale_denom *= 2) { jpeg_calc_output_dimensions(&cinfo); if (cinfo.output_width < lj->requested_width || cinfo.output_height < lj->requested_height) { cinfo.scale_denom /= 2; break; } } jpeg_calc_output_dimensions(&cinfo); jpeg_start_decompress(&cinfo); lj->pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, cinfo.out_color_components == 4 ? TRUE : FALSE, 8, cinfo.output_width, cinfo.output_height); lj->area_prepared_cb(loader, lj->data); rowstride = gdk_pixbuf_get_rowstride(lj->pixbuf); dptr = gdk_pixbuf_get_pixels(lj->pixbuf); if (!lj->pixbuf) { jpeg_destroy_decompress (&cinfo); return 0; } while (cinfo.output_scanline < cinfo.output_height && !lj->abort) { guchar *lines[4]; guchar **lptr; gint i; guint scanline = cinfo.output_scanline; lptr = lines; for (i = 0; i < cinfo.rec_outbuf_height; i++) { *lptr++ = dptr; dptr += rowstride; } jpeg_read_scanlines (&cinfo, lines, cinfo.rec_outbuf_height); switch (cinfo.out_color_space) { case JCS_GRAYSCALE: explode_gray_into_buf (&cinfo, lines); break; case JCS_RGB: /* do nothing */ break; case JCS_CMYK: convert_cmyk_to_rgb (&cinfo, lines); break; default: break; } lj->area_updated_cb(loader, 0, scanline, cinfo.output_width, cinfo.rec_outbuf_height, lj->data); } jpeg_finish_decompress(&cinfo); jpeg_destroy_decompress(&cinfo); return TRUE; } static void image_loader_jpeg_set_size(gpointer loader, int width, int height) { ImageLoaderJpeg *lj = (ImageLoaderJpeg *) loader; lj->requested_width = width; lj->requested_height = height; } static GdkPixbuf* image_loader_jpeg_get_pixbuf(gpointer loader) { ImageLoaderJpeg *lj = (ImageLoaderJpeg *) loader; return lj->pixbuf; } static gchar* image_loader_jpeg_get_format_name(gpointer loader) { return g_strdup("jpeg"); } static gchar** image_loader_jpeg_get_format_mime_types(gpointer loader) { static gchar *mime[] = {"image/jpeg", NULL}; return g_strdupv(mime); } static gboolean image_loader_jpeg_close(gpointer loader, GError **error) { return TRUE; } static void image_loader_jpeg_abort(gpointer loader) { ImageLoaderJpeg *lj = (ImageLoaderJpeg *) loader; lj->abort = TRUE; } static void image_loader_jpeg_free(gpointer loader) { ImageLoaderJpeg *lj = (ImageLoaderJpeg *) loader; if (lj->pixbuf) g_object_unref(lj->pixbuf); g_free(lj); } void image_loader_backend_set_jpeg(ImageLoaderBackend *funcs) { funcs->loader_new = image_loader_jpeg_new; funcs->set_size = image_loader_jpeg_set_size; funcs->load = image_loader_jpeg_load; funcs->write = NULL; funcs->get_pixbuf = image_loader_jpeg_get_pixbuf; funcs->close = image_loader_jpeg_close; funcs->abort = image_loader_jpeg_abort; funcs->free = image_loader_jpeg_free; funcs->get_format_name = image_loader_jpeg_get_format_name; funcs->get_format_mime_types = image_loader_jpeg_get_format_mime_types; }