[MEncoder-users] undersized x264 encodes?

[Loren Merritt]

On Wed, 1 Nov 2006, Guillaume POIRIER wrote:
> On 11/1/06, Scott Zadigian <scott.zadigian at gmail.com> wrote:
>
>> I'm calculating my bitrates by dividing my desired file size in kilobits by
>> the duration of the video and the same method is producing very accurate
>> results using xvid.  Am I setting up my x264 options incorrectly or doing
>> something else incorrectly?
>
> Probably not. x264 is just too efficient and doesn't need all the
> bitrate you thow at it to produce a good picture quality, hence the
> undersize.

Not likely, even aside from RC's diagnosis.
a) x264 will tell you when a 2pass encode doesn't need to fill the 
requested bitrate.
b) While x264's bitrate is lower at any given quality level, x264's 
default minimum quantizer is much higher bitrate than xvid's default 
minimum quantizer.

--Loren Merritt