I wait to load images from memory (jpegs and tiffs) into gdk_pixbuf_loader_write(). I have sample/test code that loads jpegs just fine but fails to display tiff images. The tiff images open fine with other viewers (eye of gnome etc) so the tiff is valid; I;ve also used imagemagick to create tiffs from jpegs and these also fail to load/display in my sample code.
Running strace on my sample code with a tiff image, I can see the gdkpixbuf loader opened ok:
open("/usr/lib64/gdk-pixbuf-2.0/2.10.0/loaders.cache", O_RDONLY) = 7
...
open("/usr/lib64/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-tiff.so", O_RDONLY|O_CLOEXEC) = 7
Is there anything specific I need to handle when using tiff files? The sample test programme is below.
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <glib.h>
#include <gdk-pixbuf/gdk-pixbuf.h>
#include <gtk/gtk.h>
void
on_destroy (GtkWidget * widget G_GNUC_UNUSED,
gpointer user_data G_GNUC_UNUSED)
{
gtk_main_quit ();
}
int
main (int argc, char *argv[])
{
FILE *f;
struct stat st;
guint8* buffer = NULL;
gsize length = 0;
GdkPixbufLoader *loader = NULL;
GdkPixbuf *pixbuf;
GtkWidget *window;
GtkWidget *image;
GError** err_ = NULL;
if (argc == 1) {
printf("no files\n");
exit(1);
}
memset(&st, sizeof(st), 0);
stat(argv[1], &st);
if (st.st_size == 0) {
printf("%s is empty\n", argv[1]);
exit(1);
}
buffer = malloc(st.st_size);
memset(buffer, 0, st.st_size);
gtk_init (&argc, &argv);
f = fopen (argv[1], "rb");
if ( (length = fread (buffer, 1, st.st_size, f)) != st.st_size) {
printf("failed to read all data from %s\n", argv[1]);
exit(1);
}
fclose (f);
if (argc == 3) {
printf("requesting loader for mimetype=%s on %s\n", argv[2], argv[1]);
loader = gdk_pixbuf_loader_new_with_mime_type(argv[2], err_);
if (err_ && *err_) {
g_error_free(*err_);
*err_ = NULL;
printf("no known loader for explicit mimetype, defaulting\n");
loader = gdk_pixbuf_loader_new();
}
}
else
{
loader = gdk_pixbuf_loader_new ();
}
gdk_pixbuf_loader_write (loader, buffer, length, NULL);
pixbuf = gdk_pixbuf_loader_get_pixbuf (loader);
gdk_pixbuf_loader_close(loader, err_);
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
image = gtk_image_new_from_pixbuf (pixbuf);
gtk_container_add (GTK_CONTAINER (window), image);
gtk_widget_show_all (GTK_WIDGET (window));
g_signal_connect (window, "destroy", G_CALLBACK (on_destroy), NULL);
gtk_main ();
free(buffer);
return 0;
}
I'm developing a sample demonstrating application for our barcode scanner driver. So I also encounter this issue. I managed to solve this issue, by closing the pixbuffer before calling 'gdk_pixbuf_loader_get_pixbuf'
also it's a good idea to check
if (pixbuf == NULL ){
to avoid crashes with null pointers.In 'tiff' you need to call gdk_pixbuf_loader_close otherwise it will not work. And when you close it, you can't use the same loader again.