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· Videophile
# genlock
3 messages in this thread
Joanne, thank you for what may be the definitive reply to my genlock
problems. At least I may be able to lay the thing to rest. Your "fix" is
exactly the same thing that I arrived at – loose the generation by
outputing to tape, then running that through a TBC. As I may have reported
in the message you read, CBM wanted me to send it back in on a "priority
return", as they had seen units with the symptoms I described.
What they would do about it they didn't say, and I have been suspicious
enough to -Yep the unit here until I found out more. It really is a
shame…the Amiga can be a useful graphics tool for non-broadcast and
industrial video when you choose your ground. You mentioned running the
signal through a proc amp in order to straiten things out. I tried that
with our Panasonic 5500 switcher, which has a proc amp which re-inserts
blanking. I can't recall the exact results, but I do remember that for some
reason it liked the genlock's raw signal even less than the TBC's (and they
didn't even think it was a color signal).
Using tape as an intermediary is the only acceptable way that I have found
to deal with the genlock. I should mention here one use I have for the
genlock that may interest you at Viacom if you or anyone you know is using
a Chyron VP-1. I have written a VP-1 driver for the in MBasic which has
helped me a lot in doing C.G. for commercial spots fast enough not rippped
apart by the producers. The heart of the program is the use of the mouse
pointer on-screen to move text lines accurately wherever you want them
without the iterative guesswork that a word processor and skip commands
entails.
Using the genlocker, you have on the Amiga screen all at the same time your
Chyron output, live video, and the program's text editor. In order to move
text, you simple point and click the point on the text line you wish to
move, then drag it to the point on the video image that you want it to end
up. All other formatting and text commands, such as color, font, italics,
etc., are handled with pull-down menus. Let me know if you are interested
and I will upload this for
Wow… the VP-1 driver sounds neat. Unfortunately, we have the Amiga here
in Cleveland, but our nearest system with a VP-1 is in Long Island, NY. I
was puttering around with some ideas for VP-1 drivers for the CoCo and
C-64, but never got one finished. I wonder if yours can be converted……
Getting back to Genlock, I suspect the vtr fixes the "lost color" problem
because of AGC acting on the colorburst (or what's left of it!) and
bringing it up to a level that can be recognized by the hetrodyne circuitry
of the vtr. Anyway, it works for the time being.
As far as proc amps, there are many different varities. Some simply
"stretch" and clip the sync to lop off the noise in the sync tips….
others genlock to the input with an internal sync gen chip, then completely
throw out the old sync & insert new. Some even give you phasing controls
for horizontal sync and subcarrier (burst) phase, but those are the really
expensive ones. I'm working on my own version of the above, using the
National Semiconductor sync gen chip, but I'm still in the "puttering
around" phase….
Wow… the VP-1 driver sounds neat. Unfortunately, we have the Amiga here
in Cleveland, but our nearest system with a VP-1 is in Long Island, NY. I
was puttering around with some ideas for VP-1 drivers for the CoCo and
C-64, but never got one finished. I wonder if yours can be converted……
Getting back to Genlock, I suspect the vtr fixes the "lost color" problem
because of AGC acting on the colorburst (or what's left of it!) and
bringing it up to a level that can be recognized by the hetrodyne circuitry
of the vtr. Anyway, it works for the time being.
As far as proc amps, there are many different varities. Some simply
"stretch" and clip the sync to lop off the noise in the sync tips….
others genlock to the input with an internal sync gen chip, then completely
throw out the old sync & insert new. Some even give you phasing controls
for horizontal sync and subcarrier (burst) phase, but those are the really
expensive ones. I'm working on my own version of the above, using the
National Semiconductor sync gen chip, but I'm still in the "puttering
around" phase….