Specifications

been required on the component video outputs for some time; the earliest reference I found is for the
Sony DVP-S9000, introduced years ago. More studio paranoia. To the best of my knowledge, the only
devices currently available that can record 480p analog component video are horrendously expensive
D5 professional digital VCRs. Professional pirates may own a D5 machine, but it's unlikely that a
consumer - even one as crazy as yours truly - would own one. And we all know how effective
Macrovision is for stopping a pro pirate, so why in hell do the studios insist on screwing things up for
the consumer?
The Extron CVC200 may be vulnerable to Macrovision, but this very capable and professional company
stepped up to the plate. An exchange of e-mails quickly confirmed that it is a known problem and that
an upgrade was available. Better yet, since my transcoder was still under warranty, the upgrade would
be covered. Two weeks later, the modified transcoder had made the round trip to California and was
ready to be replaced in my system. (While it was away, I had switched the Denon into the interlaced
mode and resumed using my Faroudja Line Doubler; the Faroudja's component video inputs are quite
impervious to Macrovision's nonsense.) I found that the updated Extron did indeed pass stable video,
but alas, only for interlaced video; progressive video was still modulated by the idiotic copy protection.
I reported the results to Extron and it's currently reproducing the problem using a Denon player in its
West Coast facility. I anxiously await a solution, but I want to solve this problem now.
Perusing a few forums pointed me to Key Digital Systems, a manufacturer of specialized products for
home theater hobbyists and video game enthusiasts. Of particular interest is its One Component to
Two VGA Video Adaptor, model KD-CTCA2. This very reasonably priced transcoder accepts component
video from a DVD player or from an HDTV set top box in any of the three currently implemented
formats (480p, 720p, and 1080i) and transforms any of those signals into the RGB-HV my projector
craves. Manipulating a tiny bank of dipswitches allows configuring the transcoder for display
compatibility, for automatic sensing of the input video format, or may be set to a dedicated video
format. An exchange of e-mails with Key Digital indicated that the video gain should remain constant in
the presence of Macrovision, so I acquired a unit.
When it arrived, I was impressed by its tiny size. The transcoder is packaged in a small plastic housing
just big enough to hold the component video input jacks, two VGA output connectors (you'll need a
breakout cable to connect the transcoder to your display), and a jack for the external power supply
that plugs directly into an outlet. I set Key Digital's dipswitches as described in its manual for my
application (negative sync, auto-format detection, separate sync pulses), hooked it up, slipped in the
AVIA disc to do a cursory check of the waveforms on my ‘scope, and didn't recognize any problem. I
then checked the waveforms with the Star Wars Episode II: Attack of the Clones DVD and found that
the video gains on the RGB channels were stable; Macrovision was gratefully ignored. With a sigh of
relief, I substituted the Key Digital for the Extron in my system, jumped to an AOTC chapter at random
and sat back, smiling in anticipation. Uh, oh. What's that? Everything's too bright!
When I examined Key Digital's waveforms on my ‘scope, I noticed that the transcoder passed the sync
pulses on the three RGB signals (the Extron strips them out), but I assumed that my projector would
clamp on full black and ignore the sync pulses. Nope. My projector, seeing horizontal and vertical sync
pulses at its HV inputs, processed the sync pulses on the RGB lines as video and put the images up on
a huge brightness pedestal, so high that adjusting the projector's brightness didn't help. I tried an
alternative dipswitch configuration (negative sync, 480p, separate sync pulses). Same result. An e-mail
to the very helpful Key Digital people revealed that an undocumented dipswitch configuration
(0000000xx for negative sync, auto-format detection, sync on green) would put the transcoder in the
RGsB mode. I tried it. Eureka! My projector recognized the RGsB signal, stripped the sync pulses out of
the RGB channels, and I had a stable, Macrovision-free picture. I jumped to an AOTC chapter at
random and sat back, smiling in anticipation. Uh, oh. What's that? White clouds are slightly pink.
Everyone is sunburned. Everything's too red! My color temperature is screwed up.
Out again came the ‘scope and the AVIA DVD. I selected the 100 IRE and 50 IRE (100% white level
and 50% white level) test patterns, found at Gray Scale & Levels / Gray Fields, and checked the Key
Digital's R, G, & B outputs. I found that at 100 IRE, the red channel was 10% higher than the green
channel, and blue was 2.1% higher than green. (For RGB video, green is 59% of the luminance, red is
30%, and blue is 11%, so I use green as the reference.) For 50 IRE, red was 10.6% too high, blue 3%
too high. The three-color channels should be the same amplitude for a pure white or pure gray video
signal. It's time for a short explanation; those wanting to avoid the technobabble may skip the next
paragraph.
Typically, a display's color temperature is set by adjusting the red, green, and blue drives for high
amplitude and low amplitude video. A color analyzer would be used to ensure that over the full video
dynamic range, white is white, black is black, and the grays in between are gray. No apparent tint
should be visible at any gray level; this is characteristic of the desirable 6,500 degree Kelvin color
temperature. I heartily recommend an Imaging Science Foundation (ISF) certified calibrator to
achieve these results on your display. Unless you have an extraordinarily good eye and know exactly
Page
3
of
7
DVDFILE.COM: Mr. Blandings Builds his Dream Theater
4/7/2003
http://www.dvdfile.com/news/special_report/tech/mrblandings/upgrades.html