[PD] opencv motion tracker external HELP!

martin.peach at sympatico.ca martin.peach at sympatico.ca
Tue May 29 17:51:36 CEST 2007

> 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().


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