Why should you care about video digitizers?
Because the way that we view, shoot, record, edit and deliver
video is changing faster than you can say information superhighway.
Just look around. The new DV format
is here, and the D stands for digital. Satellites and fiber-optic
cable deliver information digitally. Home digital-video teleconferencing
is just around the corner. Leaders in the computer industry have
decided for all of us that the World Wide Web is the place to
be. How do you supply video for these hip virtual destinations?
By digitizing it.
In this article, we’ll look at the
types of products that can give you what it takes to move into
the digital world. If you are new to computers, you may want to
get your feet wet first by capturing still images from video with
an inexpensive frame grabber. A serious hobbyist might want to
capture moving video on a computer with a motion video digitizer
or with a complete turnkey nonlinear edit system. Once you’ve
got the video on the hard drive, you’ll need some way to make
editing decisions and carry them out; this is where nonlinear
editing software enters the picture. These are the types of products
we’ll be looking at: still-capture devices, motion-capture boards,
nonlinear-editing systems and software.
Before we get into the products
themselves, however, let’s take a brief moment to bring some of
the digitally uninitiated in our audience up to speed. If you’re
a hot-shot digital whiz kid who already understands the subject
right down to the chip level, then feel free to skip ahead to
the next section. If not, don’t fret; the following introduction
to the subject should clear the way.
Ones and Zeros
How does it all work? What do video
digitizers do, exactly? Here’s the short answer: they convert
the continuously varying voltage of an analog video signal into
numerical information so you can store it on a hard drive.
Confusing? Perhaps. The important
factor to remember is this: what most people call video–analog
video–is completely different from its digital sibling. To store
video on a computer’s hard drive, you must convert the analog
signal to digital information (ones and zeros). Similarly, if
you want to transfer the images on your computer screen onto analog
videotape–VHS, for example–you have to convert them from digital
Both of these jobs–converting analog
to digital and digital to analog –are the basic operations performed
by still- and motion-video digitizers. It’s a rather difficult
task for the computer, converting analog video to a string of
numbers. A good way to get the feel of what it means to convert
analog video to digital information is to look at a digitizer
that only produces still images. As video flies by at 30 frames
per second, a still-capture board grabs one of these frames and
turns it into a picture that you can view or manipulate on your
computer. Sometimes, the computer needs a few seconds to render
the still frame on your screen. Imagine doing the same thing to
each frame 30 times a second, and you can see why motion-video
digitizers are truly a miracle of modern technology.
Also of particular concern is the
large amount of data that digital video represents. To record
raw video–full-frame, full-color, full-motion video–you’d need
a hard drive that could record about 27MB of data every second.
Most drives can’t even keep up with a moderate 5MB-per-second
data flow, much less find room to store a short video clip that
consumes more than 1GB per minute. The solution: use a codec (compression/decompression
scheme), such as MPEG or MJPEG (see sidebar). Most video capture
cards include on-board hardware to compress the incoming video
so the hard drive can keep up with it. The most common type of
codec used to compress full-screen, full-color, full-motion video
is MJPEG, or Motion-JPEG.
The three most important performance
characteristics to look for in a video capture device are its
maximum bit depth, its maximum number of vertical and horizontal
pixels, and its maximum capture rate. Bit depth refers to the
amount of color information assigned to each pixel. The number
of vertical and horizontal pixels affect the device’s capture
resolution. And the capture rate affects the overall quality of
the video. A good trio of benchmarks to consider are 24-bit color,
640×480-pixel capture resolution and a capture rate of at least
1MB/second. These guidelines are for those of you who need a good
bottom-line minimum figure for what’s necessary to output your
productions to videotape. If your final target is the Web or CD-ROM
multimedia, then you can (and should) work with slower capture
rates and fewer pixels in order to keep the size of your final
productions down in the megabyte range, instead of the gigabyte
When looking at video digitizers,
you may notice that the price goes up as you add speed (megabytes
per second) and visual quality (bit depth and resolution). The
best bet is to try to see equipment in action before you buy.
Checking Usenet discussions, or Videomaker’s Web forums (http://www.videomaker.com/forument.htm)
can also be helpful.
What use might you find for a still
capture board? You could snap some pictures of yourself and your
kids and e-mail them off to relatives and friends. You could capture
pictures from raw, unedited video and create a storyboard to help
you make editing decisions. You could use the images in printed
literature– perhaps a marketing piece about your company to sell
your video services to clients. You could use a still image from
your video as a background for titles. Or you might use the digitized
images on your Web site or in a PowerPoint presentation.
One of the most popular still-image
capture devices is Snappy from Play, Inc. For $199, this device
plugs into your computer’s parallel port and captures still images
from any NTSC video source. Bundled software includes Adobe PhotoDeluxe,
Kai’s Power Goo SE and Gryphon Morph. Snappy works with Windows
3.1, 95 and NT. Maximum capture resolution is 1500×1125 and maximum
bit depth is 24.
The AIGotcha! from AITech is a similar
product that works with Windows 3.1/95. At a suggested retail
price of $169, it delivers a maximum bit depth of 24 and maximum
capture resolution of 1600×1200. One of its main selling points
is the presence of an S-video connector, which is missing from
Another contender in this category
is the VideoShot from VideoLabs, which captures 640×480-pixels
with a maximum bit depth of 24. It sells for $199.
Movin’ On Up
There has been a lot of commotion
in the motion-video digitizer category in the past year. Current
trends include boards that digitize both video and audio, and
low-priced units that almost anyone can afford. (Note: if your
video board doesn’t capture audio, you’ll need to purchase a sound
card to fulfill this duty.)
For Web and multimedia developers,
there’s the Intel Smart Video Recorder III, a motion-video capture
card that supports resolutions up to 640×480 with 24-bit color.
At $199, the Intel Smart Video Recorder III includes Asymetrix’s
Digital Video Producer and Web Publisher software packages.
Another good choice for Web and
multimedia developers who want to work with MPEG is Data Translation’s
Broadway 2.0 ($995), a board that has the ability to capture and
compress moving images and audio in the MPEG-1 codec "on
the fly," as the video is playing. The Broadway captures
24-bit color at a maximum resolution of 352×240 pixels.
Matrox has recently introduced the
Rainbow Runner Studio, which at $249 provides an inexpensive solution
for those who want full-color, full-screen, full-motion digital
video. A companion card for the Matrox Mystique ($159) graphics
accelerator, the Rainbow Runner Studio provides a low-cost nonlinear
editing solution for home users. It can capture video from any
analog source, such as a VCR, camera or laser disc. Rainbow Runner
Studio uses hardware Motion-JPEG compression, and comes bundled
with Ulead’s MediaStudio video editing software, iPhoto Express
for image editing, a software MPEG converter (for producing videos
for use on CD or the Internet) and VDOnet’s VDOPhone for video
Fast Electronics offers the AV Master
($899), an MJPEG board that captures both audio and video. Maximum
resolution is 640×480, and the color is 24-bit. Included with
the board is Ulead’s MediaStudio Pro software, as well as Fast’s
own AVI Warp, FastCap and MediaCache utilities.
The Bravado 1000 ($699) from Truevision
is available for the PC or Macintosh platforms. The Bravado 1000
uses Motion-JPEG compression and allows you to capture 640×480-pixel,
24-bit color video directly to hard disk. The full retail version
of Adobe Premiere 4.2 (discussed later) is included.
Another popular maker of video capture
boards is miro Computer Products. Their two most current products
are the miroVideo DC10 ($399) and the miroVideo DC30 ($999). The
DC10 has a maximum capture resolution of 340×480 and a maximum
MJPEG compression of 6:1. The DC30 increases the maximum resolution
to 704×480 and the maximum data rate to 6MB/second. The DC30 board
captures incoming audio as well as video.
These are but a few of the players
in the digitizer and nonlinear editing hardware market. Many more
are listed in the buyer’s guide accompanying this article.
Having gone to all of the trouble
of getting your video onto your hard drive, what will you do with
all those zeros and ones? Edit them, of course.
For $79, the Digital Video Producer
from Asymetrix puts video editing capabilities in the hands of
any Windows 3.1, 95 or NT user. The timeline uses two video tracks,
and automatically applies transitions to overlapping video tracks.
The program includes 15 different types of transitions, including
fades, dissolves and wipes.
MediaStudio Pro 5.0 from Ulead Systems
($595) delivers 32-bit video editing for Windows 95 and NT. In
Video Editor, you arrange video, animation, audio, image and graphics
files in many popular file formats on up to 101 video and audio
tracks. You can overlay and animate text, images and video with
3D moving paths, or map overlays onto 3D spheres and cylinders.
Also included are F/X Studio, a gallery of video filters and transition
effects, Multimedia Converter, Image Editor, Audio Editor, Morph
Editor, Album and other modules for multimedia material.
Star Media Systems offers two Windows-based
products: Video Action Pro ($499) and Video Action NT ($999).
Each is a comprehensive 32-bit digital-editing software package
with transitions, filters, titling, animation, keying, morphing,
warping and sound.
Adobe’s Premiere for Macintosh or
Windows is one of the most popular and flexible nonlinear software
packages available. Premiere supports both Apple’s QuickTime and
Microsoft’s Video for Windows formats, so it can work with a wide
range of hardware and software products. Version 4.2 ($795) includes
features that optimize movies for smooth, low-data-rate playback
on CD-ROM and the Web. The graphical interface displays video
clips in "filmstrip style," with variable zoom-in and
One of the main advantages of Premiere
is the wide range of plug-in software products available from
third-party manufacturers. Products like Artel Software’s Boris
Effects Pro or Videonics’ Video ToolKit can add functionality
to your existing Premiere system without requiring a whole new
nonlinear editing software package.
Speed Razor Mach 3.5 ($1495) is
a higher-end editing and compositing software package from in:sync.
Features include many items that you wouldn’t need for most simple
hobbyist setups–features like D1 quality output (a very high-quality
digital-video format) and full-field rendering with no project-length
limits, flexible effect-compositing tools and real-time audio
mixing (from six to 20 tracks).
Speed Razor offers a character generator,
an infinite number of video tracks, an infinite number of audio
tracks, and support for time code and RS-422 deck control. The
software works only under Windows NT.
Digital Is as Digital Does
There’s no doubt about it: the world
is going digital. This is a good thing. Analog video can deteriorate
rapidly when it is played back and recorded, played back and recorded,
played back and recorded. Digital video remains pristine through
repeated manipulations, duplications and edits.
And you can use digital video on
computers, CD ROMs or DVDs, and on the Web. Five years ago, only
a few visionaries would have thought these things possible. Imagine
what the next five years might bring.
Whatever it is, you can bet it will
Videomaker contributing editor William
Ronat owns a video production company.
Glossary of Terms
- Analog Video
Video information in the form of a continuously varying voltage.
Currently, it’s the standard way of encoding a video signal for
transmission over the airwaves, through cable systems, or on videotape
or laser disc. In the not-too-distant future, however, digital
video will become the new standard.
Compression/decompression scheme used to reduce the size and data
rate of digital video files. Common codecs include MPEG and MJPEG.
- Digital Video
A way of encoding a video signal by transforming its analog waveform
into a series of ones and zeros (digital information).
- Frame Grabber
A type of video digitizer that captures only a single frame of
video. You can then view, manipulate and store this image on the
- Motion Video Digitizer
A type of video digitizer that captures a moving stream of video
for viewing, manipulation and storage on a computer.
- Motion JPEG (Joint Photographic
Experts Group) or MJPEG
A type of digital video codec that’s commonly found in motion
video digitizers. MJPEG is derived from JPEG, the type of still-image
compression that’s named for the Joint Photographic Experts Group.
- MPEG (Moving Picture Experts Group)
A popular type of digital video and audio codec. Web videos, CD-ROMs,
DVDs and digital satellite services currently use various forms
- Nonlinear Editing
The process of creating a video program from digital video stored
on a hard drive. Also called random-access editing, nonlinear
gets its name from the fact that you never have to rewind or fast
forward a videotape to access any particular "clip"
or section of the video.
- Video Digitizer
A computer peripheral that transforms an analog video signal into
a series of ones and zeros.