milo@ndmath.UUCP (12/29/86)
If anyone knows the model number of a VCR capable of unattended single frame recording without the use of an external controller I would greatly appreciate hearing about it. This would be used for recording single frame computer animation and would need some way that an external signal from a computer could trigger the recording of each frame. I have already contacted a local Sony industrial rep and several other companies but they don't know about any such machine. There also seem to be a number of different "lines" of machines put out such as industrial, commercial, professional and consumer. People that carry one line don't seem to know about any of the others. I thought that if I could get a model number I might be able to find the machine through any of the dealers. Of course...if there are any manufacturers rep's out there I would LOVE a call from you on this. Greg Corson (219) 277-5306 ...seismo!iuvax!kangaro!milo
jlange@oracle.com (Jim Lange) (04/16/91)
In article <1991Apr12.185158.6640@jpl-devvax.jpl.nasa.gov> grieggs@jpl-devvax.jpl.nasa.gov (John T. Grieggs) writes:
Ok, I just bought myself a JVC HR-D960U. This is a very nice (my opinion)
deck with jog/shuttle, flying erase heads, some sort of time stuff (we are
bouncing off the outer limits of my comprehension here), and edit pre-roll.
How do I use this to do single frame recording? Do I need something called
an edit controller? I have been staring at the instructions for setting
an insert point and starting a dub there using a second deck and the REMOTE
PAUSE terminal, but I don't really understand what that means.
I would like to be able to position the tape to a frame, poise my Amiga to
output a composite signal containing an ANIM (via DCTV), and through some
magic have that signal begin recording at that point. This seems feasible,
but is it really? I realize it means triggering an edit pre-roll - the
triggering and synchronization of that with the Amiga is what throws me.
Depending on your patience threshhold, you can do it manually. Of all of the
consumer grade VCR's I have used, the JVC HR-D960U is the most accurate and
easiest to manually recue to begin a recording at a specific frame. My
parents purchased one that I used extensively over Christmas (teaching my
father how to edit videos). I found that using the jog-shuttle to position to
a specific frame and then switching to record mode, the new scene would begin
at the very next frame EVERY SINGLE TIME! Also, the jog shuttle works while
the deck is in record-pause mode (switching to play-pause/jog while the knob
is moving then back to record-pause when you stop) so you don't have to switch
between play and record to edit many short scenes together.
I successfully used it to do single frame recording one afternoon when I had
some time. The source was a camcorder aimed at a toy soldier on the ground
(my Amiga was not with me :( ). I started by recording several seconds of
nothing (the wall) to establish a control track, then rewound to the beginning
and placed the VCR in Video-Insert mode (press [Insert] or [V.Dub] button from
play-pause). This preserves the control track for smoother playback. The
procedure to single frame record is then:
1) Unpause VCR and record a few seconds of subject.
2) Pause VCR (but don't press Stop)
3) Jog backwards until scene changes.
4) Jog forwards so last desired frame of current pose is displayed.
[Deck will now revert to Record-Pause]
5) Adjust position of subject
6) Go to step 1
I actually recorded two frames per pose and made about twenty edits. The
playback was glitch-free, but the color varied (apparently due to loss of
"color-frame" integrity) and the fixed background jumped up-and-down slightly.
This latter artifact is no doubt due to the transport not being "industrial
grade". However, I did not have the edit switch enabled which, according to
the documentation, activates a five-second preroll function and the
syncro-edit feature (as well as disabling video enhancement circuits).
Assuming that the pre-roll feature still works when manually editing (normal
pre-roll is only about 1.5 seconds), the stability of the final animation may
be improved.
If you are stringing together multiple anims, and the end of one scene does not
need to mate perfectly with the end of the last (i.e. each is a scene change
or has a deliberate pause of inactivity), this manual method may suffice.
What you cannot do without additional hardware is force the VCR to begin its
recording with a specific frame of your animation. This normally requires
SIMPTE time code and sophisticated editing equipment.
It would be worth contacting JVC to try interfacing to the syncro-edit jack.
You may luck out and find you can get within a few frames (or better). You
could use a program like The Director or AmigaVision to send a signal to the
VCR (via Arexx and a custom program) then start the animation exactly 5
seconds later (or whatever the pre-roll frame count turns out to be). The
Director 2.0 allows for very precise timing control by frame as well as nice
anim playback capability. You would still have to recue the VCR manually,
however, between scenes.
Good luck, let us know what kind of results you get.
(NOTE: I'm cross-posting this to rec.video)
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Jim Lange jlange@us.oracle.com
Oracle Corporation {uunet|apple|hplabs}!oracle!jlange
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Jim Lange jlange@us.oracle.com
Oracle Corporation {uunet|apple|hplabs}!oracle!jlange
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