You can try convert the HD movies to 848x480, it should work for any avi files with the correct codec contrainer and resolution.

You can also use Formatfactory to do the conversion to any file type and contrainer you wanted. Resolution can be edit manually and enter 848x480pixel then convert. It will keep the quality to almost the same as original.

if you stream from Tversity then you'll only get sound only for movie files. I don't know why.