[MPlayer-users] mpeg2 resolution

[Bret Hughes]

I am working with a company that is creating movies in after effects
that will be played back on (among other things) mplayer on linux.  One
of the scenarios is full screen playback on 30" lcds at 1280 x 768.  The
graphics artist tells me that the largest screen res for a mpeg2 is
720x480.  I have surfed a bunch of stuff and did find mention of the
main dvd mpeg2 format being defined as that but nothing that says that
mpeg2 itself being limited in that manner. 

Does anyone know?  the movies are developed at 1280x768 and I would like
to see mpeg2s at the native resolution.  Perhaps it is a limitation of
after effects?  He gave ma a monster mov file that is about 600M for 12
seconds but I can't seem to get mplayer to read it.  and keep confusing
myself as I try to read the mencoder stuff to try and figure out what I
need to do to convert it.

he gave me samples of the 720X480 movies to dink with.


And when I tell mplayer to fullscreen the mpgs I see this:

VDec: vo config request - 720 x 480 (preferred csp: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
VO: [sdl] 720x480 => 854x480 Planar YV12  [fs]


so now I am really confused.  

why 720X 480?  this aspect ratio is 1.5 or 6 X 4 I thought tvs were 4x3
and movies were 16 x 9


The aspect ratio of the screen is 1280/768=1.6667 or 15 x 9  Hmm no help

at least the pre scaling makes some sense:  845X480 = 1.779 or about 16
X 9

I have not seen it on a 30" screen yet but on a 17" 4x3 aspect monitor
running in x at 1280 x 768 there are black bars top an bottom.  this is
interesting to me because a browser running a flash movie at 1280X768
fills the screen ( albiet sort of scrunched up)

anyway as you can see I am looking for some guidance here.  If mplayer
is going to prescale before passing the video to xv can I tell it to
prescale to a 15X 9?  Should I have the developer create mpeg2s at that
ratio?  Are the calculations to remain in ration going to make for
better images?

I have a headache.  Please help.

Bret