[MPlayer-users] probably my usual stupid question of the week
D Richard Felker III
dalias at aerifal.cx
Fri Apr 16 18:17:19 CEST 2004
On Fri, Apr 16, 2004 at 11:03:12AM -0400, Aaron Peterson wrote:
> > Crop should probably go first. No need to use -xy and -zoom. They're
> > rather strange. Just use -vf crop=...,scale=w:h and fill in the width
> > and height to use. There are tricks to get mencoder to compute them
> > for you, but it won't align them at multiple-of-16 boundaries so
> > you're best to just figure out the right size yourself. Normally it's
> > 640x272 (2.35:1), 640x288, 640x352 / 640x368 (16:9), or 640x480 (4:3).
>
> Okay, so the original video is 720x480, aspect 1.78:1. So I ran
> cropdetect, and it tells me it wants to crop a picture 720 x 366. So I
> calculate the equivalent 640 x N ratio, and N=325 (almost). Anyway, this
> is not a multiple of 16, so I divide by 16 which is 20 something, then
> multiply 16 by 20 to get 320. So I just want to confirm that this is the
> correct method to go about all this, I would want to scale to 640x320? Or
> should I use one of the measurements you gave above instead? If I should
> use one of the above, how would I have figured out which one?
Yeah, just round to the closest multiple of 16. So in your case, 320.
> If I didn't want to scale down the video, but did want to preserve the
> aspect in a way that most players understand, do i need to use
> scale=720xXXX ?
Rescaling is the only way that most players understand... If you want
to keep the original size you'll have to use insanely high bitrate
anyway.
Rich
More information about the MPlayer-users
mailing list