[MEncoder-users] Output variable framerate?

Corey Hickey bugfood-ml at fatooh.org
Sat Jan 21 22:59:07 CET 2006


Pierre Thibault wrote:
> Hello,
> 
> I have a video (ripped from DVD) that contains two types of scenes:
> genuine 30fps interlaced scenes and 24fps scenes telecined to 30fps.
> When I use -vf pullup with -ofps 29.97, mencoder does a great job at

This won't really affect your problem, but you mean -ofps 30000/1001.
See below.

> removing all the interlacing artifacts in both types of scenes, but
> generates one extra frame every other 5 in the telecined case, giving
> a jerky output. When instead I use -vf pullup with -ofps 24, the 30fps

... -ofps 24000/1001

> scenes become jerky because of the frames dropped. So, ideally, I
> would like to encode in a variable framerate, going from 30fps to
> 24fps, depending on the scene. Is there a way to inform mencoder to do
> such a thing? For instance, I could first run  -vf pullup -ofps 29.97,

... -ofps 30000/1001

Whenever you're encoding NTSC material (such as from a DVD), you should
use the exact fractional framerates. It's fine to talk about 24fps or
23.976fps, since we know what you mean, but for encoding it's best to be
as precise as possible.

If I did my calculations right:
24     fps   -->   3.6 seconds error per hour
23.976 fps   -->   about 0.0036 seconds error per hour

Granted, the error in the later case is almost nil, but you might as
well not have any.


Anyway, besides the other suggestions in this thread, can you please
post your entire mencoder command lines?

-Corey




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