If you like the idea of desktop video, but
don’t fancy poking around inside your PC then how about this digital video
mixer from Vivanco, the latest addition to their MovieBox range
PC-based editing and post-production was
never going to be easy, it’s the nature of the beast, but Vivanco have been
doing their best to tame the technology and make it more approachable, with the
MovieBox system. Unlike most other forms of desktop video, MovieBox does not use
plug-in cards. That should please a lot of PC owners, who either do not relish the
idea of tinkering around inside their equipment, or their PCs have simply run
out of spare expansion slots.
MovieBox is based around a trio of devices,
that plug into the computer’s serial, parallel and monitor sockets. We’ve already
looked at MovieCutBox, which is the system edit controller (see VCR September
95), now it’s the turn of MovieMixBox, a 2-channel digital video mixer/processor
plus 3-channel audio mixer. Incidentally, the third component is MovieGenBox, a
PC genlock, that allows computer generated graphics, titles and images to be
mixed with video from MixBox; look out for a full review soon.
Whilst the three units were designed to work
together, they can still work as stand-alone devices, though clearly some
functions -- that depend on other components -- will be unavailable. MixBox
comes in two parts, the hardware and software. The electronics are housed
inside a slim metal cabinet, that carries all of the AV inputs and outputs. The
software is on a single 3.5-inch diskette. Our test sample also came with a ‘lite’
version of Movie Titler, a useful title generator program, though this will
mainly be of interest to system users with a GenBox.
MixBox has two input channels, that can
handle either composite or S-Video feeds, or a mixture of both. The channels
are designated ‘M’, for master and ‘E’ for effects, the master channel remains
in analogue form and is used to synchronise the second channel and the output,
so it must always be present. The E channel is digitised, it is the one where
all of the effects are carried out and is normally supplied by the second video
source, though it can be sourced from the PC in the form of an image file. The computer
communicates with MixBox via a parallel interface cable (supplied), this plugs
into the PC’s LPT-1 port, (normally used for a printer).
Software installation is carried out from
inside Windows. The disk loads from Program Manager in the usual way; it only
takes a couple of minutes to sort itself out. The set-up defaults should suit
most machines but if for any reason the PC uses a different parallel port or
interrupt it’s a simple enough matter to change the settings, using the
configure option on a drop-down menu. The only other preliminary is to select
the appropriate signal inputs, which means choosing between composite or
S-Video inputs, and deciding which input is going to be the master channel.
Once that’s done MixBox is ready to go.
The desktop display is split into five areas.
At the top there’s the signal routing plan, next to that there’s the video
processor section. This uses virtual sliders for setting the brightness,
saturation, contrast plus red, blue and green colour levels for both channels.
The bottom half of the screen is taken up with the audio mixing and tone
control sliders on the left hand side, and the master mix/wipe controls on the
right. Drop-down control sliders are used to set chromakey and lumakey levels,
and strobe speed.
At switch-on MixBox is configured for a basic
2-channel cross-fade. This can be carried out manually, by clicking and moving
the slider control with the mouse pointer, or automatically, by double clicking
on the ‘autotake’ button. The speed can be continuously varied using a second
small slider. There’s a ‘bump’ option, which gives the effect a cute little
judder as it terminates. Autotake proved to be rather unreliable, and the software
was demonstrably the root cause of several system crashes on one of our test
machines (workhorse 486/33 8Mb, Win 3.1 etc.). It worked okay on others, we
never did find out why.
Effects are selected from the toolbar at the
top of the screen, either from the menu or icons. The basic options are cross-fade,
wipe and move. Additional facilities include chromakey, lumakey, strobe and
freeze. The freeze mode works as a frame-grabber, these can be saved as bitmap
files (also gif, JPEG, pcx, tga and tiff formats), which can used as stills on
the E channel.
The software comes with a choice of 22 wipe
patterns. We suspect they should all be available immediately but on our sample
they had to be loaded one by one from system files. This wasn’t explained in
the instructions. It took a while to figure it out and several more minutes to
load them all. Once installed, a simple double-click on chosen wipe in the selection
window changes the pattern, and the icon is shown in the ‘Take’ window. In
addition to the wipes provided MixBox comes with an extra program called
MovieEditMix. This allows user to create their own custom cross-fades. It’s not
the easiest piece of software to get to know, and devising a transition can
take rather a long time, but for those with the patience and perseverance it
could prove quite useful.
The audio mix section is reasonably straightforward,
and the provision of tone controls is a definite bonus. Sound settings on both
E and M channels can be stored and the wipe/fade control can be set to audio
only or audio and video.
Synchronisation is good, the processed output
signal is stable and largely free of jitter. There is some evidence of the
digital processing taking place. A small amount of pixellation is sometimes
evident on static scenes though the processor is largely transparent; there’s
only a negligible increase in noise and no significant loss of resolution on
composite or S-Video inputs.
Transitions (wipes, fades etc.) occur in 64
steps, so there is a very slight pulsation as the image changes. This can be
quite noticeable on a slow manual cross-fade or wipe, unless you’ve got a very
steady hand. The changeover is quite clean though, and effect edges on wipes are
sharp and well defined. The choice of effects should be more than enough to
suit most users.
The chroma and luma key facilities work
reasonably well, though the degree of control is fairly coarse and the best
results are obtained when the subject and single colour background are brightly
lit. It can involves a fair amount of trial and error -- especially chromakey
-- but with care, it is possible to create some quite respectable effects.
The audio section performs very well indeed,
again there’s no additional noise and the fader action is very smooth.
Apart from those few glitches we mentioned
previously, that concerned one test machine, MixBox is generally easy to use and
combined with the other two parts of the system, forms a competent PC-based post
production set-up. At just under £1000 MixBox is a fairly expensive piece of
kit, though until recently that would have been competitive with stand-alone mixers,
assuming you already had a PC. However, the price of digital mixers has been
falling recently and the cheapest ones currently sell for less than £800, and that
includes at least one model with a much wider range of effects and facilities
than MixBox. However, compared with other desktop video products MixBox and the
MovieBox system as a whole stacks up reasonably well against the competition. It’s
certainly worth thinking about as an alternative to systems that use plug-in
cards, which can be notoriously difficult to install and configure. For that
reason alone it might appeal to movie-makers new to the joys of PC ownership,
taking their first tentative dip into the sometimes murky waters of desktop
Make/model: Vivanco PCV 4000 Movie Mix Box
Typical price: £999
System requirements IBM PC or compatible, 386 or higher plus MS Windows 3.1 or
Features: 2-channel vision mixer/processor
& 3-channel audio mixer
Effects: fade, 6 move effects, 22 wipe
patterns, chroma and luma keying, video processing (contrast, saturation, brightness RGB levels), strobe,
freeze, auto fade (variable speed), Movie Edit Mix software (creates custom
wipe & fade effects), Movie Titler (creates custom titles)
Sockets: AV in/out (phono & S-Video), PC Parallel (25 pin sub-D), DC Power in
Dimensions: 414 x 55 x 130 m
Effects definition good
Audio mixing good
Value for money ***
Ease of use
Ó R. Maybury 1996 2305