[MPlayer-users] MP4 recorded in portrait with Android phone -> OK with VLC but landscape with MPlayer/HTML5

[Reimar Döffinger]

On Wed, May 01, 2013 at 07:44:08AM +1000, Philip Rhoades wrote:
> >Ensure the video is actually recorded the right way round instead of
> >just having a matrix in some file format header describe the
> >orientation.
> 
> 
> I did record it in the desired orientation (portrait).

"recorded" was a bad word choice.
"Encoded" is the better term.
If some players display it differently that means
they display it as it was encoded, without rotating
it as a post-processing step.
The same issue exists with JPEG btw. Firefox at least
ignores the EXIF rotation as well, so phone camera images
are often the wrong way around.
However this is much less of an issue, since for JPEG
the rotating is possible to do losslessly, for video
it's unfortunately necessary to re-encode in order to completely
avoid the issue.