[MEncoder-users] Mencoder params

[Raimund Berger]

John Doe <jdmls at yahoo.com> writes:

>> In fact, another copy/paste error; there is no vqscale option with -x264encopts; 
>> only with -lavcopts...
>> ...
>> So, there's no equivalent to qscale in x264?
>
> I did some tests and found that x264 'crf=29' seems close to lavf 'qscale=5'...
> So, I guess that, like qscale, 2 passes with crf is useless... right?

Right. x264 has 3 main rate control methods, constant quantizer (qp),
constant quality resp. rate factor (crf), and bit rate (bitrate). The
former two make sense only in single pass modes. The latter can be
used in both, single and multipass. Of the former, crf is the
recommended one since it can distribute compression over time and
achieve a better overall quality.

For reference anyway, here are the MeGUI profile equivalents for
MPEG-4 ASP Q2 encoding:

(i) constant quantizer equivalent
 --qp 18 --ref 3 --mixed-refs --bframes 16 --b-pyramid --b-rdo
 --bime --weightb --filter -2,-1 --subme 6 --trellis 1
 --partitions p8x8,b8x8,i4x4,i8x8 --8x8dct --me umh

(ii) constant quality equivalent
 --crf 18 --ref 3 --mixed-refs --bframes 16 --b-pyramid --b-rdo
 --bime --weightb --filter -2,-1 --subme 6 --trellis 1
 --partitions p8x8,b8x8,i4x4,i8x8 --8x8dct --me umh