setvideo, getvideo - set and get video registers
void setvideo(long reg, long value)
long getvideo(long reg)
reg expects the name of the register to access.
value expects the value which is to be placed into reg.
FUNCTION RETURN VALUE
The returned value of getvideo is the value read from register reg, or
-1. -1 indicates that reg is not a valid register or that you queried a
video register on a system without that particular board installed.
setvideo sets the specified video register to the specified value.
getvideo returns the value of the specified video register. A generic
register, GL_VIDEO_REG, has been defined to allow you to access video
capabilities that are present across the product line. Certain video
capabilities may not be present on particular versions of Silicon
Graphics products, and these limitations are outlined below. The
previous practice was to use the DE_R1 register as the means for enabling
or disabling these video capabilities; we encourage developers to use the
GL_VIDEO_REG generic interface instead.
To enable or disable one of the generic video capabilities, call getvideo
(GL_VIDEO_REG), and store the integer return value in a local variable.
Then use one of the following bit fields from <gl/get.h> to set or clear
the bit corresponding to the video capability you wish to enable or
GLV_GENLOCK (all products)
Enables genlocking (when a genlock option is present). Note that
setting this bit only causes the main raster subsystem to accept an
external genlock signal; you will also have to program your video
option (CG2, CG3, or BVO) and have it generate the genlock clock signal
that the main raster subsystem locks to.
This bit will be indirectly set whenever you call setvideo() with a
DE_R1 video format that calls for genlock (e.g. DER1_G_60HZ)
GLV_TTLSYNC (IRIS-4D VGX only)
When set, tells the raster subsystem to expect a ttl level genlock sync
input source. Should only be used in conjunction with GLV_GENLOCK.
GLV_UNBLANK (IRIS-4D GT, GTX, VGX)
Enables raster video output when set. To prevent the X server from
periodically blanking the screen, call blanktime (0).
GLV_SRED (IRIS-4D GT, GTX, VGX, Extreme)
Enables sync on the red channel.
GLV_SGREEN (all products)
Enables sync on the green channel. On the Personal Iris, setting this
bit enables sync on the red, green, and blue channels simultaneously.
GLV_SBLUE (IRIS-4D GT, GTX, VGX, Extreme)
Enables sync on the blue channel.
GLV_SALPHA (IRIS-4D GT, GTX, VGX)
Enables sync on the alpha channel.
setvideo and getvideo support several different video boards; the board
names and register identifiers are listed below.
Display Engine Board [Toc] [Back]
CG2/CG3 Composite Video and Genlock Board
BVO Broadcast Video Option [Toc] [Back]
For information about programming the Broadcast Video Option (EV1 Board)
refer to the Broadcast Video and GenLock Option for the VGX Graphics
Board Set. This document will contain descriptions for the bit mask
assignments (defined in <gl/bvo.h> to be used when programming the
BVO_MODE_REG register or reading from the BVO_STAT_REG.
Note: In genlock mode, the BVO will temporarily lose sync whenever you
read from the BVO_MODE_REG.
VP1 Live Video Digitizer Board [Toc] [Back]
The Live Video Digitizer is available as an option for IRIS-4D GTX models
only. (it is also available on certain IRIS-4D GT models).
Iris Elan (GR2) Board
Iris Extreme (GU1) Board
Genlock is supported on the Iris Elan and Extreme graphics boards.
getmonitor, getothermonitor, setmonitor, videocmd, setmon
These routines are available only in immediate mode.
The DE_R1 register is actually present only on the video board used in
the IRIS-4D B, and G. It is emulated on all current models, but its
usage is discouraged. We encourage developers to use the GL_VIDEO_REG
interface instead when enabling or disabling generic video capabilities.
Support for the DE_R1 register emulation will not be provided in the
graphics library for future hardware products to be released by Silicon
Graphics; use the GL_VIDEO_REG interface instead to guarantee your
program's portability into the future.
Iris Indigo Entry does not support setvideo for any of the video
registers including GL_VIDEO_REG. The reg and value parameters are
ignored. On Iris Indigo Entry, getvideo returns (GLV_UNBLANK |
GLV_SGREEN) for GL_VIDEO_REG and returns -1 for all other registers.
Iris Reality Engine Graphics option only supports GLV_GENLOCK option for
Video Output format changes are not supported from both setvideo and
setmonitor. Users are advised to use setmon to change Video formats. The
symbolic constants named above are defined in the files <gl/cg2vme.h>,
<gl/bvo.h>, <gl/vp1.h>, and <gl/gr2vid.h>.
Genlock control on CG2/CG3 board is not supported on Iris Elan, and no
software support is needed to make use of the composite video capability.
Iris Elan supports genlock on the graphics board. On Iris Elan, default
is sync on the red, green, and blue signals. GLV_GENLOCK, GLV_SRED,
GLV_SGREEN, and GLV_BLUE are the possible values returned for
GL_VIDEO_REG, and -1 is returned for all other registers. On the Extreme
and Indigo2 XZ, you have the added feature of selecting the sync for one
or more of the color signals, so these two systems can also support
GLV_GREENGENLOCK for GL_VIDEO_REG. setvideo(GL_VIDEO_REG,0) will default
to setting sync on all three color channels.
To adjust genlock on Iris Elan, use setvideo (GL_ELAN_ADJGENLOCK,value)
or use the setmon command with the -j option. This value is not shadowed,
so you can't use getvideo to retrieve the genlock adjustment value.
The genlock adjustment value is specified relative to the beginning of
the line in the input signal. It starts out with a large, undocumented
value. If you need a specific genlock adjustment, you should set it
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