HP sv6 - Manual (Page 98)

hp scalable visualization digital compositor
compositor cards
Appendix A 98
rack mountable box containing a fourteen-slot backplane. Into the
backplane, three types of cards can be inserted: a controller card, an
input card and output cards.
compositor cards
The compositor must contain one controller card. It is responsible for
initializing the system, updating firmware, and communicating with the
master Workstation to update state information (mode, video rates, video
stream state, etc.). This card also accepts the stereo sync signal from the
graphics card on the master Workstation and produces the stereo sync
needed by active stereo emitters. It also controls the power switch, fan,
and status LEDs. After initialization, it only monitors the fan, power
supply, and sets the LEDs.
The input card has connections for two video input streams. In a scalable
visualization system, one input is used for the 2D stream while the
second input on that card is used for 3D. Some number of additional
input cards are used for 3D streams. The input card is responsible for
taking in digital video streams, down-sampling the data (in
super-sample scene anti-aliasing mode) and inserting the data into the
appropriate location of an internal frame buffer (in all modes) while
summing the data with the original frame buffer contents (in jitter scene
anti-aliasing mode). This frame buffer is then sent to the next input card
for insertion of its data. The final stage is for the 2D channel to
optionally average the data (divide by the number of 3D input streams
when in jitter mode), overlay its 2D rendering stream data and mask off
the non-3D data from the previous input cards.
The output card takes the composited image and produces a digital or
analog output signal that is appropriate for the display on a flat panel or
monitor. For a given display there can be two output cards. Two are used
to convert the sequential left/right image data from active stereo into a
parallel left image and a right image needed for passive stereo. To
support this, output card #1 has a frame buffer for holding the left image
while output card #2 receives the right image. When the correct left and
right images are completely received they are displayed simultaneously
while new left/right images are received.