Display images with a least 10 fps

[Timo Drick]

Hi all,

i want to display images on the Freerunner with a rate of at least 10 
frames per second.
I make some tests with pygame and pygtk. With pygtk i got maximal 2-3 
frames per second. So i developed a gtk c application to show an image 
but it is not smooth and do not reach a higher rate.
I use GtkImage to display the image.
Is there another lib to draw images at a high rate directly to the 
framebuffer for openmoko? Anyone a hint how to display images?

I attached the code to this mail do anyone have an optimization?

compile:
gcc small.c -o small $(pkg-config --cflags --libs gtk+-2.0 gthread-2.0)

best regards
       Timo
#include <gtk/gtk.h>
#include <pthread.h>
#include <glib.h>


static gboolean delete_event( GtkWidget *widget, GdkEvent  *event,
                              gpointer   data ) {
    return FALSE;
}

static void destroy( GtkWidget *widget,gpointer data ) {
    gtk_main_quit ();
}


double x_position = 0;
double y_position = 50;
GdkPixbuf *buffer;
GtkImage *image;
GdkPixbuf *scaled;
int width=450;
int height=600;

/* Multithreading test*/
void *motionThread(){
    printf("Motion thread startet.\n");
    while(1) {
        x_position+=5;
        scaled = gdk_pixbuf_new(GDK_COLORSPACE_RGB, TRUE, 8, width, height);
        double pos_y = 50;
        double scale_factor = 2.0;
        gdk_pixbuf_scale(buffer, scaled, 0, 0, width, height,
                         x_position , y_position, 
                         scale_factor, scale_factor, GDK_INTERP_BILINEAR);
        gdk_threads_enter();
            gtk_image_set_from_pixbuf(image,scaled);
        gdk_threads_leave();
    }
    pthread_exit(NULL);
}

/* Event based test. Do not work well. If the timeout is to low no image will be displayed */
static gboolean time_handler (GtkWidget *widget)
{
    if (widget->window == NULL) return FALSE;
    x_position+=5;
    double scale_factor = 2.0;
    gdk_pixbuf_scale(buffer, scaled, 0, 0, width, height,
                     x_position , y_position, 
                     scale_factor, scale_factor, GDK_INTERP_BILINEAR);
    gtk_image_set_from_pixbuf(image,scaled);
    return TRUE;
}

int main( int   argc,
          char *argv[] )
{
    GtkWidget *window;
    GtkWidget *button;

    g_thread_init (NULL);
    gdk_threads_init ();

    gtk_init (&argc, &argv);
    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
    g_signal_connect (G_OBJECT (window), "delete_event",
		      G_CALLBACK (delete_event), NULL);
    g_signal_connect (G_OBJECT (window), "destroy",
		      G_CALLBACK (destroy), NULL);
    gtk_container_set_border_width (GTK_CONTAINER (window), 5);
    
    buffer = gdk_pixbuf_new_from_file("brave-gnu-world-logo.jpg",NULL);
    scaled = gdk_pixbuf_new(GDK_COLORSPACE_RGB, TRUE, 8, width, height);
    gdk_pixbuf_scale(buffer, scaled, 0, 0, width, height,-100, 50, 
                     2.0, 2.0 , GDK_INTERP_BILINEAR);
    image = gtk_image_new_from_pixbuf(scaled);

    /* This packs the button into the window (a gtk container). */
    gtk_container_add (GTK_CONTAINER (window), image);
                                                    
    
    gtk_widget_show_all (window);
    
    // Start thread for image movement.
    pthread_t tid;
    pthread_attr_t * thAttr = NULL;
    printf("Create thread...\n");
    pthread_create(&tid, thAttr, motionThread, NULL);
    
    gtk_main ();
    
    return 0;
}