Settings to get constant quantizer at 2-nd pass

[Chabb]

Could anybody say what config is needed for
xvid to produce constant quantizer at 2-nd pass

I'm not satisfied with quantizer range
in final movie after 2-nd pass:
too wide, e.g. from 4 to 13,
and b-frames at q=13 looks AWFULL

And why in second pass target bitrate is likely to be ignored,
especially when clip is short,
(some cases almost 2 times smaller than targeted)

[foxyshadis]

Too-short clips don't give the ratecontrol time to work. Also, if you run a first pass at q2 and have a second pass with an average of q6 or 7, the rate control will be totally thrown off; it's best to define a zone closer to the average quant you expect to get (see the presets sticky for more information).

Change the b-ratio and b-offset to get more realistic b-frame ranges; the default is tuned for average q ~3-4 encodes. Presets thread has information on that too, and actually recommends explicit quantizer restrictions (in "more" options). Under/oversizing with them is very easy if you don't follow the directions, though, and even then sometimes enc isn't perfect.

The actual question of the thread makes no sense, a CQ 2nd pass is exactly the same as a CQ one-pass.