MPEG-FAQ 4.1:

Wdgt

[ Jim Frost was putting the Berkeley-Code into a Motif and/or Xt-Widget. ]
[ Its called WDGT, Version 2.0b is up-todate, but no description         ]
[ was included. This is from the man-page:]

Mpeg  is  a  version  of the MPEG player from the Berkeley
Plateau Research Group group as a widget.  It can be  used
either as a Motif widget subclassed from XmPrimitive or as
a toolkit-independant widget subclassed from Core.

Mpeg inherits from Core. The Motif version  also  inherits from XmPrimitive.
The class pointer is xmpegWidgetClass. The class name is Xmpeg.

This widget was implemented by making minimal  changes  to
the mpeg2.0 source code. Because of this, there are a num-
ber of global variables, functions and constants  that  do
not follow normal widget conventions.  Many of the mpeg2.0
options are not supported yet. Shared memory may not  work
-  it  has  not been tested.  On stepping through a movie,
the number of frames shown per step is indeterminate.