I dont think I quite understood. I tried:

#define FRAMEOUT frame

IplImage *frame = 0;

x->x_outlet = outlet_new(&x->x_obj, &s_anything); outlet_anything(x->x_outlet, FRAMEOUT);

with the same results. Maybe someone can dumb it down for me?

You can only work with atoms in pd's message system, and each atom usually contains a bang, a float or a symbol. You could convert the pointer to a float but it probably won't work because the pointer is a large integer that won't be accurately represented as a float. You could convert the pointer to a symbol using something like: char symstr[10]; t_symbol sym; sprintf(symstr, "%p", frame); sym = gensym(symstr); ...then send sym through the outlet and convert it back to a pointer at the receiving end by extracting the string from the s_name field of the symbol and passing it to atol().

Martin