From: vjurgens@ncsa.uiuc.edu (Vincent Jurgens)
Subject: Re: A/B roll audio switching
Followup-To: rec.video.production
Organization: NCSA
Date: Tue, 12 Jan 1993 22:46:05 GMT

In article <1993Jan11.173130.15280@rock.concert.net>,
barber@jazz.concert.net (Scott Barber) wrote:
> 
> In article <67200007@hpscit.sc.hp.com> joeo@hpscit.sc.hp.com (Joe Oliverio) writes:
> >Does anyone know makes and models of audio mixers that can be controlled from
> >an edit controller? Preferably through an RS-422, 9 pin type control?
> >
> >This would be used in an A/B roll system to allow the audio to switch with the
> >video. 
> 
> We have a Soundcraft audio mixing board in our suite at MCNC that
> does "audio for video" editing, i.e. the kind of automatic fading and 
> cross-fading that you're referring to.
> 
> There was a discussion on this list a few months back of various
> mixers that do this kind of thing.  I believe that you're looking at
> mixers starting somewhere around $2k for this capability.  I didn't
> save any of the messages, but maybe someone out there did, or
> remembers some of the mixers mentioned.
> 
> Scott
> 
> 
> --------------
> Scott Barber	  "I voted for the crazy, bozo, ozone men."
> barber@jazz.concert.net		"What is the freedom of the most
> MCNC, RTP, NC, BVD 	 	 free?  To act rightly!" --Goethe

			Yep, how 'bout that audio.  Another stumbling block on the way to that
$5000 Toaster-based post suite.
			We also have an earlier version, the 200BVE, of Scott's Soundcraft
mixer.

Vincent Jurgens
Media Systems Specialist
NCSA

Here is the thread from last year:
------
Article 1035 (6 more) in rec.video.production:
From: gmw1@cunixa.cc.columbia.edu (Gabe M Wiener)
(SAME) Subject: audio in A/B roll
Organization: Columbia University
Date: Wed, 8 Jul 1992 06:10:32 GMT

I'm a sound engineer who's starting to learn about video post, particularly
about A/B roll editing.  As someone quite interested in sound, I've been
curious as to how the audio portion of the edit is handled.  In my readings
and peeks into various post-production suites, I've often tried to piece
together what I've read or seen in order to make sense out of what's going
on with the sound, and have not been successful, so let me post my
questions
and maybe someone who's done this before can fill me in.

In your average A/B roll suite, let's assume you've got your two source
machines and your destination machine, all hooked through a controller.
Let's say you've got your two source machines running through a Toaster,
which as I understand it can also serve as a production switcher which
can be triggered by the editor.

So now you program up your EDL...you have your in points and your out
points
and you program your dissolves and wipes and whatnot into the toaster, and
(I assume) you program the controller with the proper timings to trigger
these.
(If I've gotten something wrong so far, please correct me)

But what the devil do you do about automating the sound?  If you preprogram
all this stuff, eventually you're just going to hit a key and the
controller
is going to lock up the timecode and go ahead and assemble the program.
Now let's say you have camera dialogue already on the tapes, but you want
to add in music and SFX.  If the controller is just going along and
assembling everything, you'd have to be mighty fast on a mixing console
to get everything right, including panning and mixing in of additional
tracks.

Even on a simple dissolve, you'd have to fade down the audio on one source
machine and fade up the audio on the other, maybe triggering a CD player
with music at the same time, etc.  I suppose if your video switcher
did audio also it would be easier, but as far as I know, the toaster
among others does not.

Since I know that a good automated audio console costs well into the
five figures range, and since I know that workable A/B Roll editing
systems exist for much less than THAT :-), I'm curious as to how the
business of audio is handled in this sort of editing.


--
Gabe Wiener - Columbia Univ.     "This 'telephone' has too many
shortcomings
gmw1@cunixa.cc.columbia.edu       to be seriously considered as a means of
N2GPZ in ham radio circles        communication. The device is inherently
of
72355,1226 on CI$                 no value to us." -Western Union memo,
1877
---

From: tell@rukbat.cs.unc.edu (Stephen Tell)
(SAME) Subject: Re: audio in A/B roll
Date: 9 Jul 92 16:02:02 GMT
<Br4I54.2yK@usenet.ucs.indi
ana.edu>
Organization: University of North Carolina, Chapel Hill

In article <Br4I54.2yK@usenet.ucs.indiana.edu>
jrkrause@copper.ucs.indiana.edu (
Jim Krause) writes:
>Building a black box that would switch audio signals at the occurance of
>a GPI trigger would not be a difficult endeavor. Toaster owners could
>certainly use such a box. (some might exist on the market now)

A few years ago I did a small studio installation with a device called a
"Crossfire" by Logitek.  It has two stereo inputs and a stereo output, all
balanced, and a GPI input.  The front panel has 8 level controls in two
rows.  Each row has controls for left and right channels of inputs 1 and 2.
LEDs by each pot indicate which ones are active ("program") and which
will fade up next ("preset").

Arming the device and then sending a GPI (or pressing the manual trigger
button) fades from the levels set on one row to those set on the other. 
The
result is rather like pulling the fader bar on a switcher to fade or wipe
from one effect to another on an old flip-flop type switcher.  Fade time
(in
seconds and tenths, I think) is set with thumbwheel switches.

Three options for fade style were selectable: equal cross fade, immediate
cut-in with the other channel fading out, and cut-out with fade-up.

I think it could be set up as 4 independent VCAs (ignoring the built-in
disolve stuff) in case one ever upgraded to an EDL-based system that could
store and generate the control voltages.

At the time I think it cost around $1400.  Lots cheaper than a fully
automated mixing board.

#include <std/disclaimer.h>
--
Steve Tell       tell@cs.unc.edu H: 919 968 1792  | #5L Estes Park apts
UNC Chapel Hill Computer Science W: 919 962 1845  | Carrboro NC 27510

---

There are some other more reasonably priced solutions than an SSL or
comparable computer-controlled console. One is the Yamaha DMP-7 and
other mixers in that line. They are 16-bit 8x2 digital mixers - not
quite up to SSL quality, but at c. $5k new quite a bit cheaper. They
can be controlled via a MIDI sequencer; every parameter of every func-
tion on the board including the 3 built in effects units can be con-
trolled by MIDI in real time. If you have a MIDI sequencer and inter-
face that can be slaved to SMPTE, then so can the DMP-7. In some ways,
in fact, it does more than the SSL and is easier to use, though of
course it's not up to professional sound quality. It's also possible
to digitally chain several together to get more channels.

Bill Alves
---
What you have said is true the Yamaha *could* be a nice post mixer.  I
am wondering just wich of the editing controllers on the market today
output MIDI for a mixer as well as the SMPTE serial control for the
tape machines simultaneously?

I may be wrong but the MIDI slave operation of the mixer is cumbersom
to use in post audio mixing.  You have to move the tape that has the
midi information on it to get the mixer to "work"

The last time I saw the Yamaha  tha channel faders didn't directly
control the channel.......
--
Chris Christensen                  The opinions I express are my own,
chrisc@gold.gvg.tek.com            and sometimes they are wrong!
916-478-3419 FAX 916-478-3887      After all, I AM only human.
---

From: david@roth-music.com (David A. Roth)
Subject: Re: audio in A/B roll
Date: Tue, 14 Jul 92 17:20:50 EST
Organization: DAVID A. ROTH MUSIC
Reply-To: david@roth-music.com (David A. Roth)
X-Mailer: uAccess - Macintosh Release: 1.5v4


In article <4820@gold.gvg.tek.com> (rec.video.production),
chrisc@gold.gvg.tek.c
om (Chris Christensen) writes:
>

There is an automated mixer for audio controlled by MIDI that is made
by Mark Of The Unicorn.  If you used a sequencer that chases timecode
you could use it to automate the mixing process via fader controls
on the Mac.

You could use multi-track tape that can do external sync and chase
time code.  The prices of SMPTE timecode DAT machines are dropping
and you could mix all the audio to DAT.  A timecoded DAT machine has
Stereo plus the time code track which can do external sync.

Either choice will cost you several thousand.  The MIDI mixer might
work out if you already had a MIDI set-up of some type.  I think these
are under $1k but I'm not certain.

David
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