MPEG Video Software Decode for OpenVMS AXP
	     (based on the Berkeley v2.0 MPEG code)

	     Ported by Patrick L. Mahan, TGV, Incorporated
		(Mahan@TGV.COM)

This is a release of the MPEG v2.0 viewer for OpenVMS AXP.  It
implements the MPEG standard as described in the Committee Draft
ISO/IEC CD 11172 dated December 6, 1991 which is sometimes refered to
as the "Paris Format".

This release contains everything to compile and display MPEG movies. 
The top directory contains the Unix sources for the MPEG viewer. 
There are two subdirectories.  [.VMS] contains the previous released
VMS code for  the MPEG viewer that have been ported  by Me to the
Alpha under OpenVMS AXP v1.5 including modifications to add a CLD
interface to the application.  [.MOVIES] contains the current movie
distribution from the Berkeley FTP site.

To build the distribution, set default to [.VMS] and issue the command
@MAKE.  This will cause the MPEG viewer to be built on your system and
requires DEC C v1.3 and DECwindows Motif 1.1.  After the image has
been built, modify the file MPEG_PLAYER.CLD and change the IMAGE
clause to point to the location of the MPEG_PLAY.EXE.

To display a MPEG video, simply issue the following commands:

	$ SET COMMAND [.VMS]MPEG_PLAYER.CLD
	$ MPEG/QUIET [.MOVIES]BIGE_ANIM.MPG	! Display the STTNG

The MPEG command supports the following qualifiers:

	/NOP	 : causes the player to ignore and not display any
		   "P" type frames.
	/NOB	 : causes the player to ignore and not display any
		   "B" type frames.
	/DISPLAY : causes the player to open the window on the
		   indicated X Windows Display.  /NODISLAY causes
		   the MPEG player to dither but does not display
		   the output.
	/DITHER  : selects from the following list a dithering option.

          ORDERED - ordered dither.

          ORDERED2  -  a  faster  ordered  dither.  This  is  the
               default.

          MBORDERED - ordered dithering at the macroblock  level.
               Although  there is a noticeable decrease in dither
               quality, this is the fastest dither available.

          FS4 - Floyd-Steinberg dithering  with  4  error  values
               propogated.

          FS2 - Floyd-Steinberg dithering  with  2  error  values
               propogated.

          FS2FAST - Fast Floyd-Steinberg dithering with  2  error
               values propogated.

          HYBRID - Hybrid dithering,  a  combination  of  ordered
               dithering  for  the  luminance  channel and Floyd-
               Steinberg 2 error dithering  for  the  chrominance
               channels.  Errors  are NOT propogated properly and
               are dropped  all  togethor  every  two  pixels  in
               either direction.

          HYBRID2 - Hybrid dithering as  above,  but  with  error
               propogation among pixels.

          2X2 - A dithering technique using a 2x2 pixel area  for
               each  pixel. The image displayed is 4 times larger
               than the  original  image  encoded.  Random  error
               terms are added to each pixel to break up contours
               and gradients.

          GRAY - Grayscale dithering. The image is dithered  into
               128  grayscales. Chrominance information is thrown
               away.

          COLOR - Full color display (only available  on  24  bit
               color displays).

          NONE - no dithering is done,  no  image  is  displayed.
               Used to time decoding process.

          MONO  -  Floyd-Steinberg   dithering   for   monochrome
               displays.

          THRESHOLD  -  Floyd-simple  dithering  for   monochrome
               displays.

	/SHMEM   : causes MPEG to use / not use the SHMEM extension.
		   permitted values are ON and OFF.

	/QUIET   : suppresses pringing of frame numbers, timing
		   information, and most error messages.

	/LOOP    : makes the MPEG player loop back to the beginning
		   after reaching the end of the animation.

	/LUMINANCE
		 : sets the number of colors assigned to the luminance
		   component when dithering the image.  The product of
		   /LUMINANCE, /CR_RANGE and /CB_RANGE should be less
		   than the number of colors on the display.

	/CR_RANGE
		 : sets the number of colors assigned to the red
		   component of the chrominace range when dithering.
		   The product of /LUMINANCE, /CR_RANGE and /CB_RANGE
		   should be less than the number of colors on the
		   display.

	/CB_RANGE
		 : sets the number of colors assigned to the blue
		   component of the chrominace range when dithering.
		   The product of /LUMINANCE, /CR_RANGE and /CB_RANGE
		   should be less than the number of colors on the
		   display.


More information can be found in the $*. files located in the toplevel
and subdirectories.

Several mailing lists for MPEG have been established:

  mpeg-list-dist@CS.Berkeley.EDU 
	General information on the decoder for everyone interested 
	should be sent to this list.  This should become active after
	11/20/92

  mpeg-list-request@CS.Berkeley.EDU
	Requests to join or leave the list should be sent to this 
	address. The subject line should contain the single word 
	ADD or DELETE.

  mpeg-bugs@CS.Berkeley.EDU
	Problems, questions, or patches should be sent to this address.