As, Manono pointed out in
http://forum.doom9.org/showthread.ph...734#post746734 in December, you seem to be improperly using GK's compression test.
In in the log in that thread, I note:
Code:
Quality: 0.188 bits/(pixel*frame).
CompCheck3: 0.000 bits/(pixel*frame).
CompCheck5: 0.156 bits/(pixel*frame).
. If I'm reading that correctly, you attempted to create a file with 120% of the b/p*f of your compression test. You will never reach your intended file size, since the test shows a maximum obtainable b/p*f of 0.156 at that resolution.
I know you've searched and read a lot; perhaps you've missed this sticky in the DivX Encoding forum; its applicable to XviD also:
http://forum.doom9.org/showthread.php?t=24584
Best practice among the members seems to be aiming for a value in the 60-80% range (AutoGK aims for 75%). Doom9's guides recommend 40-60%, and those should provide acceptable results.