what is the best and right way to patch a file in inno setup using xdelta

[maybeknow]

I Keep getting this error...
and I dont know why


here is the line of code

ExtractTemporaryFile('XDelta3.dll');
ISxDeltaExtract(0, 0, 0, 256000, ExpandConstant('{app}\test1.txt'), ExpandConstant('{tmp}\test1.txt.diff'), ExpandConstant('{app}\out3.dat'), false, false);

oh I think I made a big mistake...
what is the type of first argument of function? should I pass a compressed file to it??