NAME

     h261Play - CMT H.261 Video Playback Object



SYNOPSIS

     h261Play prefix ?options?



DESCRIPTION

     The h261Play command creates a new H261 Play object, used to
     decode and display Intra-H.261 encoded video.

     The name of the new object (which is created by appending  a
     unique suffix to prefix) is returned.  This name is also the
     name of a Tcl command that can be used  with  the  following
     options.


OPTIONS

  object accept scatter-buffer-list
     Accepts scatter-buffer-list as h.261  encoded  video  to  be
     displayed.  See the section below on INPUT.

  object destroy
     Destroys the packet source named object.

  object stats
     Unimplemented -- will return a  list  containing  statistics
     about   the  packets  this  object  has  received,  decoded,
     displayed, etc...

  object ready
     Tell object to get ready to start accepting data.  This  can
     only be done if required configuration slots noted below are
     set.  Data received when object is not ready are ignored.

  object unready
     Opposite of ready described above; object  will  ignore  any
     incoming data until it is readied again.

  object deviceList
     Returns a list of valid device names for the -device  confi-
     guration slot described below.

  object configure ?-options?
     Sets configuration parameters for the  packet  source  named
     object.  Valid options are:

          -device
               Chooses a device  to  handle  video  decoding  and
               display.   The  string  "default"  will choose the
               default device.  Other valid values are  given  by
               the deviceList command described above.  This slot
               must be set before object can be readied.

          -lts
               The Logical Time System (LTS) object  this  object
               should  use  to make timing decisions for decoding
               and displaying  video.   This  slot  must  be  set
               before object can be readied.

          -xid
               The X window ID  of  the  window  in  which  video
               should  be  displayed.   For most Tk widgets, this
               value can be found  with  the  winfo  id  command.
               This  slot  must  be  set  before  object  can  be
               readied.




INPUT

     An h261Play object register an atom @objName.accept so  that
     it  can  be the target of the out command of another object.
     It takes the buffers it receives, places them on a queue  of
     buffers  to be decoded, and then allows the device to decode
     whatever buffers it can.



BUGS

     Plenty.  Many configuration slots are missing and it has not
     been thoroughly tested on different platforms.  It should be
     considered alpha quality; improvements will be made  eventu-
     ally.



SEE ALSO

     rtpSrc(l), rtpDest(l), buffer(l), cmwish(1)



AUTHORS

     Andrew Swan (aswan@CS.Berkeley.EDU)