No subject

have a concept of or need to care about.

> > Can you explain what kind of initialization those sources have to do
> > and why they can't figure out that they have to do it in some other way?
> 
> I can explain the particular case of ASS: the resolution has to be set once
> just after the render has been created, and then each time it changes. The
> problem is the first case: the resolution can not be set immediately,
> because it will only be available on the next "update" call.

The two questions are:
1) why is the resolution from the previous file not still available
2) why does the ASS source not know that it has never been initialized
   or not with valid values and fixes this however and as soon as it can?