[MEncoder-users] Newbie question

[Ender wyvern]

Vielen Dank, herr Doeffinger! The culprit was indeed the default 4:4:0
sampling factor in ImageMagick. Adding a -sampling-factor 4:2:2 option (to
ImageMagick, not MEncoder) fixed it.

On Tue, Dec 29, 2009 at 3:42 PM, Reimar Döffinger
<Reimar.Doeffinger at gmx.de>wrote:

> On Tue, Dec 29, 2009 at 02:51:42PM -0700, Ender wyvern wrote:
> > I'm trying to use mencoder to create a video slideshow with no audio
> using a
> > set of jpeg images. My mencoder script (see below) works as long as all
> the
> > images are in landscape orientation (4000x3000 instead of 3000x4000). If
> any
> > of the images are portrait-oriented, the script fails. I don't control
> the
> > orientation of the jpegs provided by the end user; they may be portrait
> or
> > landscape. Therefore, I use imagemagick to resize and letterbox the
> > portrait-oriented photos to 4000x3000. The script still fails if it
> contains
> > these letterboxed images. Furthermore, even if I simply resize (and
> distort)
> > the images to 4000x3000, the script *still* fails. Can anyone tell me
> what
> > I'm doing wrong here? Thanks!
>
> That last part should have given you a hint that something about your
> analysis is completely wrong.
> The reason it fails is that the "bad" JPEGs are encoded using 4:4:0
> colour downsampling which MPlayer currently can not handle.
> This is probably due to the rotating though, I can't say why the
> unrotated ones do not work since you gave no information at all (in
> particular not MPlayer output) for that case.
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