Posted by Ed on 3, 2000 at 11:47 PM:
In Reply to: DVD +Mpeg 2 card and TV Out posted by x-ian on 3, 2000 at 9:08 PM:
There are two ways to play DVD movies on your computer:
using software decoding and using hardware decoding.
If you use software decoding, the contents of the
dvd will be decoded by a program that will produce
moving images in your regular vga card. Therefore,
you can play these movies on any display device
supported by your VGA card. For the case of ATI
cards, ATI sells a dvd decoding program to do just
that. The drawbacks are that playback quality will
totally depend on the speed of your computer and that
you won't benefit from 5.1 Dolby/DTS audio tracks, as
output will be through your regular sound card.
The second option is to add a DVD decoding card. This
card is like a dedicated CPU which takes all the work
of decoding the dvd info. All your PC does is pass bytes from
the DVD drive to the dvd card. However, the video is
produced by the decoding card: the output from your VGA
card (windows desktop, etc.) is combined with the output of the decoder and then
sent to the monitor/video set. This means that you can only
play dvds on devices supported by the decoder card (usually
s-video and vga in standard vga modes). The pros are that
you don't require a fast computer, you get better-than-vhs
video quality and you get full 5.1/DTS audio output. The
cons is that you can't get DVD output out of your regular
VGA card: all you get is an empty window where video will
be overlaid later by the decoder card.
To illustrate what I just said, look at my setup:
At home, I have an ATI Xpert@play and Creative Labs
DVD drive and decoder card. The ATI card's vga out is connected
to the decoder's vga in and my monitor is connected to the
vga out of the card. My tv set is connected to the
s-video output of the decoder card, so that I can see
full screen movies (but not the windows desktop). If
I connect my TV to the s-video/composite output of my
Xpert@play, I will see the windows desktop (but no movies).
If I connect my monitor to the vga out of the decoder card,
I can see movies playing in a window in the Win95 desktop, but
if I connect it to the vga out of the ATI, I won't see
the movies, just an empty window. As you may have noticed,
I am not using ATI's DVD decoding software, which is why I
can't see movies in a desktop window when I connect my
monitor to the ATI's vga out.
Which brings me to answering your question: you can use both
your ATI card and the video decoding board with no problems. However
the decoder card does not replace your VGA card.
My apologies if I rambled too much. Just wanted to share
my experiences with ATI cards + DVD players.