Specifications
Video Cards for Multimedia
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playback, but they typically do not deliver the same quality or compression ratio. Following are two
of the major codec algorithms:
■ JPEG (Joint Photographic Experts Group). Originally developed for still images, JPEG can compress
and decompress at rates acceptable for nearly full-motion video (30fps). JPEG still uses a series
of still images, which makes editing easier. JPEG is typically lossy (meaning that a small amount
of the data is lost during the compression process, slightly diminishing the quality of the
image), but it can also be lossless. JPEG compression functions by eliminating redundant data
for each individual image (intraframe). Compression efficiency is approximately 30:1
(20:1–40:1).
■ MPEG (Motion Picture Experts Group). MPEG by itself compresses video at approximately a 30:1
ratio, but with precompression through oversampling, the ratio can climb to 100:1 and higher,
while retaining high quality. Thus, MPEG compression results in better, faster videos that
require less storage space. MPEG is an interframe compressor. Because MPEG stores only incre-
mental changes, it is not used during editing phases.
If you will be capturing or compressing video on your computer, you’ll need software based on stan-
dards such as Microsoft’s DirectShow (the successor to Video for Windows and ActiveMovie), Real
Network’s Real Producer series, or Apple’s QuickTime Pro. Players for files produced with these tech-
nologies can be downloaded free from the vendors’ Web sites.
To play or record video on your multimedia PC (MPC), you need some extra hardware and software:
■ Video system software, such as Apple’s QuickTime for Windows or Microsoft’s Windows Media
Player.
■ A compression/digitization video adapter that enables you to digitize and play large video files.
■ An NTSC-to-VGA adapter that combines TV signals with computer video signals for output to a
VCR. Video can come from a variety of sources: TV, VCR, video camera, laserdisc player, or DVD
player. When you record an animation file, you can save it in a variety of file formats: AVI
(Audio Video Interleave), MOV (Apple QuickTime format), or MPG (MPEG format).
Depending on the video-capture product you use, you have several choices for capturing analog
video. The best option is to use component video. Component video uses three RCA-type jacks to
carry the luminance (Y) and two chrominance (PR and PB) signals; this type of connector commonly
is found on DVD players and high-end conventional and HDTV television sets. However, home-
market video capture devices usually don’t support component video. A typical professional capture
device designed for component video, such as Pinnacle Systems’ DC2000DV, retails for about $2,000.
The next best choice, and one that is supported by many home-market video-capture devices, is the
S-video (S-VHS) connector. This cable transmits separate signals for color (chroma) and brightness
(luma). Otherwise, you must use composite video, which mixes luma and chroma. This results in a
lower-quality signal, and the better your signal, the better your video quality will be.
You also can purchase devices that display only NTSC (TV) signals on your computer. The built-in
digital movie editing features found in Windows Me and Windows XP, the increasing popularity of
computer/TV solutions, and broadband Internet connections make onscreen full-motion video an
increasingly common part of the computing experience. Because of the growing importance of
onscreen full-motion video, more and more recent CPUs have added features to enhance playback—
including MMX and SSE instructions found in the Pentium II, Pentium III, Celeron, and AMD
Athlon and Duron and the instruction set found in the Intel Pentium 4’s NetBurst microarchitecture
and SSE2. Computers that use Windows XP Media Center Edition are ready out of the box to capture
and digitally record video from TV for playback later, functioning as a personal video recorder (PVR).
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