Encyclopedia of Computer Science and Technology

virtual community 493Prencipe, Loretta W. “Management Briefing: Do You Know theRules and Manners of an Effective Virtual Meeting?” Info-World 23, no. 18 (April 30, 2001): 46.Spielman, Sue, and Liz Winfield. The Web Conferencing Book. NewYork: AMACOM, 2003.Videoconferencing Product Reviews from PC Magazine. Availableonline. URL: http://www.pcmag.com/category2/0,1874,4836,00.asp. Accessed August 23, 2007.Winters, Floyd Jay, and Julie Manchester. Web Collaboration UsingOffice XP and NetMeeting. Upper Saddle River, N.J.: PrenticeHall, 2002.video editing, digitalWhen videotape first became available in the 1950s, recorderscost thousands of dollars and could only be affordedby TV studios. Today the VCR is inexpensive and ubiquitous.However, it is hard to edit videotape. Tape is a linearmedium, meaning that to find a given piece of videothe tape has to be moved to that spot. Removing or addingsomething involves either physically splicing the tape(as is done with film) or more commonly, feeding in tapefrom two or more recorders onto a destination tape. Besidesbeing tedious and limited in capabilities, “linear editing” bycopying loses a bit of quality with each copying operation.Today, however, it is easy to shoot video in digital form(see photography, digital) or to convert analog video intodigital form. Digital video is a stream of data that representssampling of the source signal, such as from the chargecoupleddevice (CCD) that turns light photons into electronflow in a digital camera or digital camcorder. This processinvolves either software or hardware compression forstorage and decompression for viewing and editing (sucha scheme is called a CODEC for “compression/decompression”).The most widely used formats include DV (DigitalVideo) and MPEG (Motion Picture Expert Group), whichhas versions that vary in the amount of compression andthus fidelity.In a turnkey system, the input source is automaticallydigitized and stored. In desktop video using a PC, a videocapture card must be installed. The card turns the analogvideo signal into a digital stream. The most commonlyused interface to bring video into a PC is IEE1394, betterknown as FireWire, which has the high bandwidth neededto transfer video data.Once the video is captured, it can be stored in framebuffers in memory and edited in various ways using a varietyof software. Expensive turnkey systems come withadvanced software, while desktop video users can choosefrom products such as Media Studio Pro or Adobe Premiere.The editing interface usually has a timeline and thumbnailsshowing the location of key frames in the sequence. Individualclips can be extracted and tweaked with motion andtransition effects; a variety of filters (see plug-in) can beapplied to the video. The accompanying sound track(s) canalso be edited. Once things look right, the software is toldto render (create) the finished video and save it to disk.The ever-increasing processing power and disk capacityof today’s PC is likely to make real-time video editing morefeasible. This means that video can be played back directlyfrom the edited timeline without transitions or effectshaving to be rendered first. Digital video cameras are alsolikely to increase in picture quality. Already desktop videois proving to be an affordable, viable alternative to expensiveturnkey systems for many applications.Meanwhile, like digital photography, digital video is rapidlybecoming a creative medium for the masses, aided byeasy-to-use basic software for Macintosh (such as iMovie)and numerous products for Windows. Another driver forthe proliferation of this medium is the ease with which videoscan be uploaded and shared (see user-created contentand YouTube).Further ReadingBrandon, Bob. The Complete Digital Video Guide: A Step-by-StepHandbook for Making Great Home Movies Using Your DigitalCamcorder. Pleasantville, N.Y.: Readers Digest, 2005.Digital Video Editing. Available online. URL: http://videoediting.digitalmedianet.com/. Accessed August 23, 2007.Digital Video Resources. Available online. URL: http://www.manifest-tech.com/links/mmtech.htm. Accessed August 23,2007.Goodman, Robert M., and Patrick McCrath. Editing DigitalVideo: The Complete Creative and Technical Guide. New York:McGraw-Hill, 2003.Pogue, David. iMovie 6 & iDVD: The Missing Manual. Sebastapol,Calif.: O’Reilly Media, 2006.Underahl, Keith. Digital Video for Dummies. Hoboken, N.J.: Wiley,2006.virtual communityBack in the mid-19th century, a number of technical professionalsbegan to “chat” online without meeting physically—theywere telegraph operators who relayed messagesacross the growing web that one author has called “TheVictorian Internet.” When computer networking began togrow in the 1970s, its own pioneers used facilities such asnewsgroups (see netnews and newsgroups) to discuss avariety of topics. By the early 1980s, users were interactingon-line in complex fantasy games called MUDs (Multi-UserDungeons, or Dimensions) or MOOs (Muds, Object-Oriented).A little later, bulletin boards and especially systemssuch as the WELL (Whole Earth ’Lectronic Link) based inthe San Francisco Bay Area (see bulletin board and conferencingsystems) provided long-term outlets for peopleto share information and interact on-line.Looking at the WELL, a writer named Howard Rheingoldintroduced the term virtual community in a 1993 book. Heexplored the ways in which a sufficiently compelling and versatiletechnology encouraged people to form long-term contacts,form personal relationships, and carry out feuds. Whenon-line, participants experience such a venue as the WELL asa place that becomes almost as tangible (and often as “real”)as a physical place such as a small town or corner bar.Virtual community members who live in the same geographicalarea sometimes do get together physically (theWELL has had picniclike “WELL Office Parties” for manyyears). Members can band together to support a colleaguewho faces a crisis such as the life-threatening illness of ason (on the WELL, blank postings called beams are often