I ran into a problem trying to watch DVDs on my Beige G3MT. I tried using VLC (it sucks) then I read where someone used a program called Pacifist and used it to open the OS X installer files and installed the DVD player from OS X.
I am using OS X 10.2.8 and I did the same thing using pacifist to open the OS X installer files on the install disk of OS X and I'm here to tell you it works. Great DVD play, no choppyness just excellent playback. You can get pacifist from verisontracker.com.
You do need to have the ATI 16meg PCI video card or better installed in your machine
I your G3 has a Rage IIc than YES you do need to upgrade your video card to something better. The IIc can not handle DVD video.
I should have said at least a Rage 128 with 16megs ram as that is what I'm using
i have an ATI Rage 128 with 16mb ram and i can watch dvd's on my B&W with osx, but not OS9. ive tried several dvd roms and nothing seems to change, i used an imac DV400 drive for a little while and that didnt change anything. os9 for me is just picky i think.
In order to watch DVDs in OS 9 you need to have the DVD Decoder card with the ATI 128 or upgrade to a Radeon 7000 with 32megs of ram. However I do not think you can have both. It will be either on OS 9 that you can watch DVDs or OS X and OS X does not use the Decoder card on the ATI 128. So as you say you can watch them on your B&W with OS X go for it.
My post concerned the Beige G3 with the ATI card and OS X. if you use X you do not need the decoder card and by using pacifist you can extract the DVD player from the install disk for OS X and install it your Apps folder and it will work.
The reason being is that OS X will not install the DVD player on the Beige G3 weather you have a DVD-Rom installed or not and as far as OS 9X being pickey yes you are right