Please correct me if this is the wrong section of the forum for this post!

I am trying to convert a bunch of jpeg's into a video that i can play in windows with powerpoint.

I do this:

mencoder mf://file*.jpg -mf type=jpeg -ovc lavc -lavcopts vbitrate=10000 -vf scale=628:300 -o test.avi

at this point, the avi looks perfect, but wont play in powerpoint! Then I do this

mplayer somefile.avi -vo yuv4mpeg
mpeg2enc -f 2 -b 8000 -a 2 -F 4 -n n -M 3 -o output.mpg stream.yuv

at this point, the mpg plays in powerpoint, but there are a few compression artifacts that make it look a bit crappy

is there something i can do in these last two commands to make it the same format (so it plays in power point) but not add the artifacts? The files are only about 2mb so making them even 10x bigger would not be a problem