I first notice I wasn't getting Xv support when I tried running mplayer and get
this message:

Xlib:  extension "XFree86-VidModeExtension" missing on display ":0.0".
vo: X11 running at 1280x1024 with depth 24 and 32 bpp (":0" => local display)
It seems there is no Xvideo support for your video card available.

I thought perhaps it was because mplayer doesn't recognize XServers XVideo
extension because it looks specifically for the "XFree86-VidModeExtension".

I ran xvinfo and I got the following message:
X-Video Extension version 2.2
screen #0
 no adaptors present

I also tried it with xine and go this message:
This is xine (X11 gui) - a free video player v0.9.23.
(c) 2000-2003 The xine Team.
main: video driver <xv> failed

According to xdpyinfo I do have the XVideo extension:
name of display:    :0.0
version number:    11.0
vendor string:    freedesktop.org
vendor release number:    6600
maximum request size:  4194300 bytes
motion buffer size:  256
bitmap unit, bit order, padding:    32, LSBFirst, 32
image byte order:    LSBFirst
number of supported pixmap formats:    6
supported pixmap formats:
    depth 1, bits_per_pixel 1, scanline_pad 32
    depth 4, bits_per_pixel 4, scanline_pad 32
    depth 8, bits_per_pixel 8, scanline_pad 32
    depth 16, bits_per_pixel 16, scanline_pad 32
    depth 24, bits_per_pixel 32, scanline_pad 32
    depth 32, bits_per_pixel 32, scanline_pad 32
keycode range:    minimum 8, maximum 135
focus:  window 0x1a00005, revert to PointerRoot
number of extensions:    15
    BIG-REQUESTS
    Composite
    DAMAGE
    MIT-SCREEN-SAVER
    MIT-SHM
    MIT-SUNDRY-NONSTANDARD
    RANDR
    RENDER
    SHAPE
    SYNC
    X-Resource
    XC-MISC
    XFIXES
    XTEST
    XVideo
default screen number:    0
number of screens:    1

screen #0:
  dimensions:    1280x1024 pixels (339x271 millimeters)
  resolution:    96x96 dots per inch
  depths (6):    1, 4, 8, 16, 24, 32
  root window id:    0x36
  depth of root window:    24 planes
  number of colormaps:    minimum 1, maximum 1
  default colormap:    0x20
  default number of colormap cells:    256
  preallocated pixels:    black 0, white 16777215
  options:    backing-store NO, save-unders NO
  largest cursor:    1280x1024
  current input event mask:    0xdac031
    KeyPressMask             EnterWindowMask          LeaveWindowMask
    KeymapStateMask          ExposureMask             StructureNotifyMask
    SubstructureNotifyMask   SubstructureRedirectMask PropertyChangeMask
    ColormapChangeMask
  number of visuals:    2
  default visual id:  0x21
  visual:
    visual id:    0x21
    class:    TrueColor
    depth:    24 planes
    available colormap entries:    256 per subfield
    red, green, blue masks:    0xff0000, 0xff00, 0xff
    significant bits in color specification:    8 bits
  visual:
    visual id:    0x34
    class:    TrueColor
    depth:    32 planes
    available colormap entries:    256 per subfield
    red, green, blue masks:    0xff0000, 0xff00, 0xff
    significant bits in color specification:    8 bits

Is the XVideo extension simply not finished? or am I doing something wrong here?