Is there a setting that would force the joomla 1.0 with new 2.5.2 mambot to NOT enlarge the videos to the default video size that has been preset.

I have 1000 videos in my library, the largest 800X600 and various other sizes from 320X240 and 640X400 .

Id like the smaller videos to play at their original size but centered in the larger 800X600 default container selected in the mambot settings.  right now they are stretched which causes poor video quality.