portuesi@tweezers.esd.sgi.com (Michael Portuesi) (11/14/89)
>>>>> On 13 Nov 89 23:24:23 GMT, sutherla@qtp.ufl.edu (scott sutherland) said:
s> SYSTEM:
s> Amiga 2000 (Stock)
s> CMI VI 500
s> Zenith Stereo VHS VCR
s> QUESTION ONE: Is it possible to record an audio signal simultaneously on
s> on the stereo and audio tracks?
VHS VCR's record with three kinds of audio:
linear mono (low-fi)
linear stereo (low-fi, sometimes with Dolby NR)
Hi-Fi stereo
The linear audio (both mono and stereo) is recorded on a separate
track. Hi-Fi Stereo is recorded along with the picture. To correct
your diagram:
s> ------------------------------------------------------------
s> =================Linear Mono and Stereo Audio===============
s> \ \ \ \ \ \ \
s> \ \ \ \ \ \ \
s> \ \ \ \ \ \ \
s> \ \ Video and HiFi Stereo Audio \
s> \ \ \ \ \ \ \
s> \ \ \ \ \ \ \
s> \ \ \ \ \ \ \
s> ===================Control Track===========================
s> -------------------------------------------------------------
A bargain-basement VCR is only capable of recording linear mono.
VCR's that are labeled "Stereo" record in low-fidelity (worse than the
average cassette deck) on the linear tracks. VCR's labeled "Hi-Fi
Stereo" record in high-fidelity (with specs a bit shy of a compact
disc) on the diagonal tracks along with the picture.
Your question, "is it possible to record audio simultaneously on both
the stereo and audio tracks" is a bit ambiguous, because there are two
different stereo systems used in VHS VCR's. A Hi-Fi VCR will record
stereo on the Hi-Fi track, and mono on the linear track, for
compatibility with non-HiFi units.
A Hi-Fi unit will play back the Hi-Fi track if it exists, else it will
play the linear audio (in low-fi of course). My Panasonic PV-4860 (a
Hi-Fi Stereo VCR) is unable to play back linear stereo (it comes
through as mono). I think this is the case for most Hi-Fi VCRs,
though it isn't much of a loss since most stereo stuff these days is
also Hi-Fi.
Because your Zenith VCR is labeled "Stereo", but not "Hi-Fi", it
probably records only linear stereo. Another non-HiFi Stereo unit
should play that back just fine. A mono VCR should play back a linear
Stereo track in mono only.
s> QUESTION TWO: If the VCR is receiving 2 video signal inputs at the same
s> time, one from the RF cable and one from the RCA composite video cable,
s> does one override the other? If so, which one? If it is the RF, can this
s> be overcome? And does the other, unused video input cause interference?
s> (Okay, so this is a multi-part question.)
This depends on the VCR itself. My VCR has a switch which determines
where the audio is coming from -- the VCR's built-in tuner (the RF
cable), or the RCA jacks in back. Depending on the way the switch is
set, you can record video and audio from the RCA jacks, video from the
tuner and audio from the RCA jacks (simulcast), or video and audio
from the tuner. Your VCR should have a similar switch or set of
switches to control this behaviour. I would have to look at the
instruction manual for your VCR before I could give you any more
information.
s> Well, I went to a video store to talk to someone that both Radio Shack
s> and McDuff's had recommended as a person who might might know the answer
s> to my questions. But his explanation only complicated things.
[explanation deleted]
His explanation was correct, confusing as that may be.
s> So now I am really confused. I thought I had it all straight in
s> my head, but this fly in the ointment has turned my brain back into
s> video MUSH. CAN ANYONE SHED SOME LIGHT ON MY PREDICAMENT????
If you think you're confused, be glad you're not Joe Average Consumer.
The companies who make VCR's take advantage of this confusion to sell
VCR's with only low-fi capability under the guise of "Stereo sound."
If that is all you are looking for, fine, but I think a lot of people
are being fooled into buying something they're not really getting.
Also, a lot of people who buy "Stereo" or even "Hi-Fi Stereo" VCRs
will wonder why they can't watch or tape their favorite TV programs in
stereo. This requires a separate MTS (multi-channel televsion sound)
decoder that is part of the tuner section of the VCR. The decoder is
completely independent of whether the VCR is mono, stereo, or Hi-Fi
stereo. But the VCR makers don't stop to tell that to the consumer.
Good luck. Hope this info helps.
--M
--
__
\/ Michael Portuesi Silicon Graphics Computer Systems, Inc.
portuesi@SGI.COM