The real movie clip size?

i have a movie clip on the main timeline… inside that clip is an image… about ~1MB in size…

when i add this code to the mc:

 
trace(this.getBytesTotal());

then flash shows that the size is 4… how to get the real size of the movieclip ?
i cannot use trace(_root.getBytesTotal()); because i want only the movie clip size… not the size of the entire *.swf file