[x264-devel] 2-pass Rate Control Question?

[???]

Toward the end of the function init_pass2(x264_t *), there's a loop iterating for a fit for expected_bits (toward all_available_bits), 
"for(step = 1E4 * step_mult; step > 1E-7 * step_mult; step *= 0.5){"
where each frame's rate control entry has a field "expected_bits" accumulating the expected bits at the end of the loop. 

It seems the accumulating order is the display order. Shouldn't it be the encoding order?

Thanks for any help,
-Peter