I've seen GDIFF(Generic Diff Format) in wikipedia, and I wander is there any command line tool implements this standard. Now the best I have is LibXDiff, but it's a library, I'll need some extra work to make it run.
I know when it comes to binary-differ, VCDIFF(xdelta, etc) and bsdiff would have better compression rate, but in my case I really need a straight forward one. VCDIFF copies anything before current window(if my poor English reading was right about this article), and bsdiff's patch file format would be more complex.
update
Finally I found VCDIFF with xdelta3 is actually good and working, when "disable small string-matching" and "disable external decompression" is toggled, AND it has a pretty good "printdelta" command that prints very useful(for my app) information so that I don't really neet to extract VCDIFF format from the patch file.