Chapter 1

DVDs and Computers 119
log overlay, which takes the analog VGA signal output from the graphics
card and keys in the video, while others use video port extension (VPE), a
direct digital connection to the graphics adapter via a cable inside the computer.
Analog overlay may degrade the quality of the VGA signal. See “Why
Can’t I Take a Screenshot of DVD Video? Why Do I Get a Pink or Black
Square?” for more overlay info.
Many Macintosh models come standard with DVD-ROM, DVD-RAM, or
DVD-RW drives. The included Apple software DVD player uses hardware
acceleration in the ATI graphics card. The still-unreleased QuickTime MPEG-
2 decoder may use the Velocity Engine (AltiVec) portion of the PowerPC (G4)
chip for video and audio decoding. DVD-ROM upgrade kits and decoder
cards for Macintoshes were made by E4 (Elecede) (Cool DVD, C-Cube chip)
[E4 has gone out of business], EZQuest (BOA Mac DVD), Fantom Drives
(DVD Home Theater kit: DVD-ROM or DVD-RAM drive with Wired MPEG-2
card), and Wired (Wired 4DVD, Sigma EM8300 chip [same card as Hollywood
plus]; MasonX [can’t play encrypted movies]; DVD-To-Go [out of production];
Wired was acquired by Media100 but later reconstituted).
The Sigma Designs NetStream 2000 DVD decoder card supports Linux
DVD playback. InterVideo and CyberLink have also announced DVD player
applications for Linux, although the CyberLink player is only available to
OEMs. In addition, there are free software players for Linux, Unix, BeOS,
and other operating systems: MPlayer, OMS (LiViD), VideoLan, and Xine.
Computers have the potential to produce better video than set-top DVD-
Video players by using progressive display and higher scan rates, but many
PC systems don’t look as good as a home player hooked up to a quality TV.
If you want to hook a DVD computer to a TV, the decoder card or the
VGA card must have a TV output (composite video or s-video). Video quality
is much better with s-video. Alternatively, you can connect a scan converter
to the VGA output. Scan converters are available from ADS
Technologies, AITech, Antec, AverLogic, AVerMedia, Communications Specialties,
Digital Vision, Focus Enhancements, Key Digital Systems, RGB
Products, and others. Make sure the scan converter can handle the display
resolution you have chosen: 640x480, 800x600, and so on, although keep
in mind that even 800x600 is beyond the ability of a standard TV, so higher
resolutions won’t make the TV picture better.
The quality of video from a PC depends on the decoder, the graphics
card, the TV encoder chip, and other factors. The RGB output of the VGA
card in computers is at a different frequency than standard component
RGB video, so it can’t be directly connected to most RGB video monitors.
If the decoder card or the sound card has Dolby Digital or DTS output, you
can connect to your A/V receiver to get multichannel audio.