Grass Valley Kalypso Installation Planning Guide - Manual (Page 64)

64 Kalypso Installation Planning Guide
Section 3 — Kalypso Classic Frame
chrominance value for each pixel. In some critical applications, however,
there is something to be gained by utilizing unique chrominance values for
each pixel for the highest input resolution when computing the chroma
key.
It is important to note that the chroma keyer always does 4:4:4 processing.
However, if the key source is a 4:2:2 signal, the chroma keyer computes the
missing samples using interpolation. In the case of full bandwidth key
sources, the chroma keyer actually receives chrominance samples for every
pixel location from the external device.
Kalypso Solution
The Kalypso Video Production Center has a superior solution for full band-
width chroma keys which keeps analog-to-digital conversion out of the
digital switcher chassis and minimizes the number of input BNCs con-
sumed by each 0:4:4 source. In addition, customers can accommodate any
number of 0:4:4 sources as desired — limited only by the number of avail-
able digital inputs.
The Kalypso Video Production Center keeps analog signals out of the
digital switcher chassis, but uses only two SDI input BNCs for a full band-
width chroma key. The video fill is still a CCIR-601 standard video signal
which comes in on one of Kalypso’s inputs. The key source comes in on a
separate input BNC.
The 8950ADC module has a special 0:4:4 mode that takes the RGB analog
input from a camera or other chroma key source and converts it to a special
0.4.4. signal format for Kalypso. One 8950ADC module is used for each full
bandwidth chroma key source.
As far as the Kalypso input board and crosspoint system know, the key
source looks just like any other standard CCIR-601 video signal. However,
all of the 0:4:4 chrominance samples you need to do a full bandwidth
chroma key are present in the luminance and chrominance data bits of the
CCIR-601 signal.
Note This special 0:4:4 chroma key signal cannot be viewed on a standard digital
waveform monitor.
Any pair of Kalypso inputs may be used for a 4:2:2 / 0:4:4 chroma key fill/
source pair, so the total number of full bandwidth chroma key inputs is
limited only by the total number of Kalypso inputs available.
See the 8950ADC Analog to Component Digital Converter Instruction manual
for detailed information. Online documentation is available on the Grass
Valley Group web site. The URL for the Grass Valley Group website is
found on the copyright page at the front of this manual.