Mpeg1 works just fine in my 770.
Problem: because I think that mpeg4-files are smaller than mpeg1-files, I tried some Windows programs to convert DVD/mpeg2-files to mpeg4 with both of subformats DivX and XviD, but they don't work in my 770.
770's demo file IceAge2_trailer.avi is DivX 352x208 and naturally it plays in 770. So 770 is able to play mpeg4s/DivX's and my problem seems to be the conversion to DivX.

Has anybody succeeded to make (in 770) playable DivX- or XviD-files? (Instructions in maemo-wiki are for Linux-PC.)
If so, which (Windows) converter and which codec? (mpeg2 to mpeg4)