I have mint 9 isador, and I'm able to transcode from mpg to avi (xvid) perfectly. I tried with a new installation of Mint 12 and all I get using the exact same mencoder commands is a black video screen for the avi file.
I do see a DRI failure too.
Is there any way to compare the video codecs and mencoder settings to see what might be installed in one version of mint and not the other?
Anyone willing to help me solve this real mystery?