01-18-2008, 12:18 PM
Thanks for that--
I googled the VLC, and although it does have some deinterlacing filters, I also found the extract below, which says in the last sentence that the VLC still shows up the same defect (unless I'm misreading?).
"One quality issue that really bothers me is that __all__ video-sourced DVDs seem to have rather severe deinterlacing artifacts when played on a Mac. By video-sourced I mean DVD material that was produced for TV or that was originally recorded on video rather than film. Products like music and concert videos, PBS documentaries, classic TV programs, etc. The lack of quality varies somewhat from DVD to DVD, but it appears the same on every Mac I've tried (G3 desktops, G4 PowerBooks, G4 towers).
The sad part is that these very same DVDs look fine on my home DVD player and they also look particularly __outstanding__ on my Celeron PC running the PowerDVD player software. I've also seen similar deinterlacing defects on a few film-based DVDs (which also look fine on my PC). The problem appears whenever there is any subject or camera motion or during scene cuts. What you see is a horizontal combing effect that can really degrade the image quality. On some DVDs it is so distracting that it makes the viewing experience somewhat uncomfortable (i.e. you become engrossed in the picture quality and then combing, combing, combing). All of the DVDs in question are U.S. retail releases (i.e. no DVD copies or pirated material).
[I see this issue at times - the ATI march 2002 retail card driver update has an adaptive deinterlacing option for DVD, but it only seems to be available if you have a retail card installed. (That control panel option did not appear in OS X with a PowerBook G4 and onboard ATI Radeon mobility chip, but is an option with the retail cards - see my 8500 Radeon review's OS X software page for a pix of the control panel, etc.) The ATI cards in my experience have better DVD image quality and lower cpu usage than the Nvidia cards, at least with the current OS X/DVD player software.-Mike]
A number of users have complained about this problem over on the Apple forums. However, just as many have responded that they've never seen this problem. Admittedly it doesn't happen on all DVDs and if you typically view your DVDs over the computer's S-video interface while connected to a small and/or low-quality TV display you might not even notice the problem (unless you look very carefully). Nevertheless, I'm certain that this problem does exist so I'm hoping that someone has a solution or that a future software release from Apple will provide a fix .
By the way, VideoLan shows this same defect and considering that I've seem this same problem on both ATI and NVIDIA graphics hardware I'm certain that it is only a software limitation in the Mac DVD players."