passenger seat, and your pals are following you down an obscure

back road. Their view is perpetually of your back bumper. The

conversation is limited to cell phones, two-way radio, or shouting out the

window. Ditch old-school analog communication and set up a Wi-Fi

video session!

Use a simple webcam or another video source and the folks in the trailing

car feel as if they are riding shotgun on point.With two cars on a road trip

sporting wireless and videoconferencing, you will have a virtual party on the

highway.

system between two cars. The passengers in each car will be able to

see and talk to the people in the other car up to a distance of 300 feet

or more.

Before we get started, there’s a small amount of preparation and testing

you’ll need to do. You will need the following:

(VFW), such as a USB webcam

Once the components are assembled and tested, install them in the car and

go for a road trip! (See Figure 14-1.)

The very idea of a video screen operating in the car means that there

should be a driver and a passenger at a minimum. The passenger

will act as an electronics operator (EO) handling all of the equipment

and computer management.

Driver safety is paramount. A video system like the one you build here could be a distraction to

the driver. Ensure that all precautions are taken against driver distraction. When planning a trip

like this, extra care is essential.

Videoconferencing is more than just video. It also includes audio and data sharing. In its highest

form, videoconferencing enables multiple participants across the globe to share documents

and presentation materials, and perform instantaneous collaboration in a nearly transparent

“window” to another part of the world.

There are systems that cost over $50,000 and use multiple flat-panel video displays for corporate

boardroom meetings, like the incredible system by Tandberg shown in Figure 14-2. There

are also near-zero-cost person-to-person systems like Microsoft NetMeeting.

This chapter barely scrapes the surface of videoconferencing.To learn more, visit

Whether the system being used is the free program like NetMeeting, a medium cost package

like the Polycom ViaVideo desktop system, or the high-end system like Tandberg’s, they all

interoperate based on videoconferencing standards. These standards (developed by the

International Telecommunications Union, or ITU) define every aspect of the videoconferencing

experience. The ITU standards make it possible to use programs by different vendors on different

platforms.

Some of the relevant videoconferencing standards:

H.320—Videoconferencing standard using Integrated Services Digital Network, ISDN

H.323—Videoconferencing standard used over packet-switched networks (LANs,

T.120—Real-time data conferencing protocol

VoIP—Voice-over-Internet Protocol

This is just a snapshot. There are hundreds of protocols involved in a single videoconferencing

“h323.”

As the computer entrenches itself more firmly into every facet of entertainment and communications,

you can bet that things will change rapidly. This chapter will introduce a single facet of

the video/computer integration and add a wireless link to make things interesting.

Microsoft NetMeeting will be used in a point-to-point videoconference over a point-to-point

wireless connection. That is, we will set up a NetMeeting session over a peer-to-peer wireless link.

The worlds of videoconferencing and wireless communications each use the terms “point-topoint”

and “multipoint.” The definitions are as you’d expect, one-to-one versus many-to-many.

But it can be a little confusing when not paying attention.

The steps for accomplishing a videoconferencing session over Wi-Fi are as follows:

Although in-car data conferencing is quite possible, it won’t be explored in this chapter.

Possibilities include war drive program sharing, editing documents while driving to a meeting,

text chatting about the guys in the front seat, transferring files, and so on.

First things first: get a video source working on the laptop. There are several methods for

doing, this depending on what’s available to you.

A video source (more commonly called a camera) is obviously the first step in getting a videoconference

going. Here, a few of the most popular cameras are listed and the interaction with

your computer is explained. Most computer-capable cameras are digital and communicate

directly with the computer. The more ubiquitous analog camera needs a capture device to convert

the analog into a digital format. And the Ethernet camera bypasses all of this by including

its own computer and serving Web pages with embedded video.

By far, the easiest cameras to get working on a modern Windows laptop are the USB cameras,

The downside to USB cameras is their relatively poor quality as compared to consumer video

products, like camcorders. USB webcams are designed for use over the Web at low bandwidth.

The largest USB camera picture size is 640 480 pixels. Figure 14-3 shows a Logitech webcam.

Some camcorders can display DVD-like video on the computer.With many newer camcorders

supporting the IEEE1394 standard (Apple FireWire and Sony i.LINK) the incoming video is

pure digital with no degradation of quality. Unfortunately, few videoconferencing programs

directly support the IEEE1394 interface. The workaround is to use third-party software as an

IEEE1394 to VFW converter. One product that does this is WebCamDV by OrangeWare,

Gnomemeeting is an open source NetMeeting-like program for Linux systems. It is one of the

Most cameras have outputs for composite video in the form of RCA connectors or analog

video using an S-Video connector. The computer will need a video capture device to work with

video in these popular analog formats. The Dazzle division of Pinnacle Systems makes several

PCMCIA cards that capture video, although they are harder to find.

The upside to analog video is the huge availability of cameras that support it. Composite video

is a format available for almost all televisions these days, so virtually all camcorders have composite

video at a minimum. Also, there are thousands of dedicated camera products that output

composite video. Security cameras, for example, tend to support output composite video. The

downside is the poor quality of composite RCA video.

Composite video generally uses the ubiquitous “RCA jack” connector while S-Video uses a special

4-pin mini-DIN connector. When capturing, use S-Video if possible. It’s the highest quality

analog video format.

Ethernet cameras have built-in Web servers and do not generally include direct computer connections.

The method of use for an Ethernet camera is to attach the camera to an Internet connection,

then browse to the camera using a standard Web browser.

In effect, an Ethernet camera creates a video feed automatically. If you want a plug-and-play

car-to-car video feed try this: place a wireless Ethernet camera in each car, and connect to each

other’s camera via its Web browser. Figure 14-4 shows a diagram of how this more expensive

solution would work. By definition, this is not videoconferencing. But you can still see and hear

each other. Ethernet cameras usually cost from a couple hundred to several thousand dollars

depending on features and quality.

Ethernet cameras are often used in remote surveillance situations. Due to the stand-alone design

of Ethernet cameras, they are not generally suitable for videoconferencing.

As we stated before, the computer needs to bring in a video signal. This is either done through

the USB port, or an analog capture device (which can also be USB). In any case, the camera or

capture device manufacturer must include Windows software to allow Windows to work with

the webcam. This is in the form of an “imaging device” driver.

A “device driver” is a small program that translates information from the software world of the

operating system to the hardware world of the camera, printer, network adapter, or whatever.

Windows has hundreds of built-in device drivers. New hardware products need to install

updated device drivers, usually from a CD-ROM packaged with the hardware.

Most video applications on Windows use yet another software layer called Video for Windows

(VFW). High-end applications like Adobe Premiere do not require VFW. But less expensive

or free programs like NetMeeting usually need it. Figure 14-5 shows the basic configuration of

a video and audio capture.

Up until the later versions of Windows, there was no way to see if your video source was working

properly.Windows 98, for example, only included a “test camera” button in the Device

Manager. So, the easiest way to see if video is working in Windows is to use a video-capable

program and attempt to capture or display live video from the camera.

Most camera manufacturers include video capture programs. Follow the instructions with your

camera to get the program up and running. Then test the camera with that program. If it works

okay with the vendor’s choice program, chances are good that it will work with Windows and

other programs.

Camera A

Camera A

Camera B

Camera B

Two-party, or point-to-point, videoconferencing is the most common form of videoconferencing.

This method only requires that each participant’s computer have the software installed.

Calls are placed directly from one person directly to the other over a common medium (like the

Internet). Figure 14-6 shows a directly connected point-to-point videoconferencing session.

Videoconferencing products are merging (as with all technology) into video phones, instant

messaging plug-ins, and even cellular multimedia messaging services.Tracking this field is

becoming very difficult as definitions are changing.

That said, let’s point out a few popular videoconferencing products:

There are many more applications, but most of them cost more than $1000, and they certainly

fall outside the scope of this book. Many low-cost or free video chatting programs are entering

the market in the form of instant messaging clients (AOL IM and Microsoft MSN are the

biggest). These are not really videoconferencing products as they do not interoperate. Also,

many of the newer applications need full-time access to the Internet, so they are not a viable

option for high mobility video.

Multi-party, or multipoint, videoconferencing is where multiple participants connect to each

other. The key element in multipoint videoconferencing is the central server, or multipoint

control unit (MCU). Calls are placed from each user to the MCU server. The MCU receives

calls from each participant and relays the video to every other participant. See Figure 14-7 for

an example of multipoint videoconferencing.

www.openh323.org.

Multipoint Control Unit servers act as call handlers. Software that is meant to only handle a

single videoconferencing session can interact with many participants through an MCU.

As mentioned previously, many newer products are entering the scene as video “chatting”

clients. The most popular of these are Microsoft Messenger and AOL Instant Messenger.

Some others include Apple iChat, iVisit, iSpQ, CUWorld (descendant of CU-SeeMe),

CamFrog, ICUII, and TrackerCam.

For another list of video products, visit: http://myhome.hanafos.com/~soonjp/.

The problem with Internet video chatting is the reliance on a single, central, authentication

system. Users must register with the service provider first, then sign-on to the service over the

Internet. After that a managed list of “buddies” or “rooms” is made available.

This works fine when you’re “tethered” to the Internet, but it will not do for a highly mobile

peer-to-peer video session. This project requires a completely stand-alone system, without

reliance on a central server. NetMeeting fits the bill perfectly.