Ogle is a dvd player with support for menus and 
subtitles, and fairly good audio/video 
synchronization.  

Due to limitations in OpenBSD, it cannot
use any audio 5.1 output system and will always
output stereo sound.

Other video applications like mplayer and vlc exist,
that play more video formats, and can play mpeg2 video
from the disk, but ogle currently has better synchronization
and extensive menu support.

As shipped, ogle cannot descramble DVDs. There are
a few DVDs out there with no scramble protection.
However, ogle will recognize and use an installed
descrambling library (see converters/libdvd in the
ports tree).

As shipped, ogle has a text-based interface. 
The ogle_gui, okle, and goggles yield alternative 
GUI interfaces.

To run ogle, you need a graphics card well supported 
by Xorg, including the Xvideo extension in YUV mode,
and a sound card with 48KHz output (ATI card owners
may wish to use the ATI-4.1.0.i386.tgz package)
You can check your display Xvideo capabilities with
xdpyinfo (presence of the Xvideo extension) and
xvinfo (presence of an adapter with correct YUV 
capabilities).
A positive test will usually look like:
xvinfo
    Number of image formats: 4
	...
      id: 0x32315659 (YV12)
        guid: 59563132-0000-0010-8000-00aa00389b71
	...
which is the encoding that ogle is looking for.

Alternately, at the expense of more cpu power,
ogle can also use SystemV shared memory, but the
shared memory requirements exceed default GENERIC parameters.
You will need to crank them up. 

Starting with OpenBSD 3.3, sysctl(8) can modify the shared memory 
parameters.  A reasonable choice would be:

kern.shminfo.shmseg=32
kern.shminfo.shmall=32768

(to add to /etc/sysctl.conf, or to tweak manually with sysctl).

Overall, ogle needs about 50% cpu for full-framerate decoding
on a PIII700 with an ATI Mach64 Mobility and an ESS 
Maestro 2.

If Xvideo YV12 is not available, ogle roughly needs 120% cpu
on the same machine in 24 bits mode, and full screen rescale 
is not available.  On i386, it's highly recommended to go 
to a 16 bits mode, where MMX acceleration code exists (requirements
go down to 70% cpu). 
If you can, you may also wish to add several `non-standard' 
modes to your xorg.conf. The most useful being 720x576.

FLAVORS: altivec (ppc only)
Uses altivec vector unit for a huge speed-up.  Only works on
powerpc platform with altivec hardware support.
Altivec is present on all PowerPC G4 processors. Altivec is
not present on G3 or earlier (60x) processors.