[FFmpeg-user] conversion from wmv to avi is not working

[mouli s]

hello im trying to convert .wmv to .avi im using the following parameters

-f avi -r 29.97 -vcodec libxvid -vtag XVID -s 640x480 -aspect 4:3 -maxrate
1800kb -b 1500kb -qmin 3 -qmax 5 -bufsize 4096 -mbd 2 -bf 2 -flags +4mv
-trellis -aic -cmp 2 -subcmp 2 -g 300 -acodec libmp3lame -ar 48000 -ab 128kb
-ac 2

but the conversion is not proper it chops, video is not clear how to solve
this problem????? FYI - this conversion is for *XviD FullScreen*


but when i pass this ordinary parameter alone

-ab 128 -b 1200

it works fine conversion is good wats wrong with the first parameter i
mentioned.... thanks for any replies.