Mathematica 7 allows advance processing of graphics. I have used it to convert a series of PNG plots from root to this animated movie (~30MB) .
A minimal sufficient code is here:
path = "/Users/balewski/Desktop/outMovie/frame.png";
imgL = {};
For[i = 1, i < 95, i++, (* buil list of images *)
name = StringInsert[path, ToStringi, -5];
img = Importname;
imgL = AppendimgL, img
];
M4 = ListAnimateimgL (* build in-memeory animation *)
Export"/Users/balewski/Desktop/jasM4b.avi", M4, "avi" (* export animation *) ----
It is very slow, the last line - doing the 3 sec long movie - took an hour+.
Here is full "Mathematica Notebook" with working example, also show below as PDF.