[MEncoder-users] How are -vf filters ordered? (Was: to crop or not to crop for DVB sources)

[Joe Emenaker]

On Sun, 11 Feb 2007, Nico Sabbi wrote:
> RC wrote:
>   
>> On Sun, 11 Feb 2007 16:12:57 +0100
>> "Pierre Catello" <pierre.catello at gmail.com> wrote:
>>     
>>> -vf crop=544:575:0:1 -vf expand=544:576:0:1
>>>       
> -vf crop=544:575:0:1,expand=544:576:0:1 is very easy to use
>   
This brings up a question I've been wondering about... which I haven't 
found an answer for in the man pages.

mplayer/mencoder seems to allow for you to "build" filter lists with 
-vf-add, -vf-pre, -vf-clr, correct? So, I'm figuring that something like:

   -vf opt1  -vf-add opt2
is the same as
   -vf opt1,opt2

and
   -vf opt1  -vf-pre opt2
is the same as
   -vf opt2,opt1

and, finally, something like
   -vf opt1  -vf-clr  -vf-add opt2
is the same as
   -vf opt2

That's not too hard to understand. What I'm unclear about is how the 
per-file options come into it. Since mencoder/mplayer lets you put these 
same options after any media source, like as in:
   mplayer <options for all sources> source1 <additional options for 
source 1>  source2 <additional options for source 2>

then, what happens if I do something like:

  mplayer -vf opt1 -vf-pre opt2 -vf-add opt3  dvd://  -vf opt4  -vf-pre 
opt5  -vf-add opt6
(or maybe)
  mplayer -vf opt1 -vf-pre opt2 -vf-add opt3  dvd://        -vf-pre 
opt5  -vf-add opt6

What order are these six options added to the filter list?

- Joe