Xine (and Kaffeine) Aspect Ratio Problem
It seems that Xine is stretching (horizontally) all of my videos. I can verify this by setting output.disable_scaling to 0 (off). This happens regardless of the aspect ratio settings I use.
I read in Xine's docs that this may be related to the "DisplaySize" parameter in the xorg.conf file. (I have a viewsonic vp201s) I noticed my settings were "DisplaySize 410 310," which is what xorg configured for this monitor. I also tried my own settings (from viewsonic's page) 408.94 x 307.34 and I got the same results.
I have tried different video processors (xShm as well as the default Xv) and the only way I can seem to get non-stretched videos is to set output.disable_scaling to 0 (off).