[MPlayer-users] Problem with 'scale' negative options.

[RC]

This really isn't a bug, more like a limited feature...

Scale's negative options are very useful, but they don't always work. 
'-2' works fine if you want to adjust the height of a video, but not the
width.

For instance, I sometimes use:  -vf scale=-1:-2
Scaling the height to match the width, compensating for aspect.

Unfortunately, -2 doesn't work in place of width, unless you manually
specify height:  -vf scale=-2:480

The above works, but requires you to know the pre-scaled height ahead of
time, which isn't always possible.  

I would expect any of the following should work, but do not:
scale=-2:-1
scale=-2:0
scale=-2

I've also tried every different combination of the negative options,
but never have success.  Is there some workaround?  Is the limitation
ever going to be fixed?