GVO(7)									GVO(7)

NAME    [Toc]    [Back]

     gvo - Serial digital video	option for Onyx	InfiniteReality	graphics

DESCRIPTION    [Toc]    [Back]

     GVO is a video option for the Onyx2 workstation equipped with
     InfiniteReality graphics. It provides a broadcast quality serial
     component digital video output, compliant with ITU-R BT601-4 and SMPTE
     259M. Two links are supplied per SMPTE RP-125, to allow the alpha planes
     of	graphics to be used as a matte or key signal.

     The GVO is	configured via the ircombine(1G) command and the setmon(3G)
     command. Parameters may be	controlled from	user software via the
     XSGIvc(3) X extension.

   Modes of Operation    [Toc]    [Back]
     There are two modes of operation of the GVO:


     Low-bandwidth mode
	  In this mode,	the GVO	will output a portion of the video that	is
	  being	sent to	some other monitor. In this way, it will consume no
	  additional system bandwidth. The cursor will appear in both the GVO
	  output and the main monitor output. To select	this mode, select the
	  channel to shadow using ircombine.


     Low-latency mode
	  In this mode,	the GVO	will make its own requests from	the
	  framebuffer.	This requires additional system	bandwidth; however, it
	  has two advantages:  the GVO can output from a section of the
	  framebuffer that is not being	sent to	any other output; and the GVO
	  video	output will have the lowest latency possible. (In fact,	in
	  this mode, the GVO will introduce no latency at all).	The cursor
	  will appear in the GVO output	or the main window output, but not
	  both at the same time. To select this	mode, select 'None' on the
	  ircombine window for GVO under 'Source Channel'.  This is the	mode
	  for professional installations that require compatability with a
	  house	sync.

   Gamma    [Toc]    [Back]
     GVO has its own gamma tables that can be configured through
     ircombine(1G).  or	XSGIvc(3) and are independent of the DG5 gamma tables.

NOTES    [Toc]    [Back]

     In	low-latency mode, a suitable genlock signal must be supplied, or the
     GVO will not function correctly.

     in	low-bandwidth mode, the	source channel must have a frame rate that is
     faster than the GVO field rate (59.94 frames/sec NTSC, 50.00 frames/sec
     PAL)





									Page 1






GVO(7)									GVO(7)

SEE ALSO    [Toc]    [Back]

     ircombine(1G), setmon(1G),	XSGIvc(3)


									PPPPaaaaggggeeee 2222