[MEncoder-users] Newbie question

[Reimar Döffinger]

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.