Choppy Video Playback On Rev B Imac G5 20

berving

Registered
hi!

I recently bought a rev B imacG5 20" 2 Ghz which i equipped with 1,5 GB of RAM.
since upgrading ro 10.4.2 and QuickTime 7, video playback - in both VLC and in games like Ghost Recon, Halo and Max Payne - gets choppy and sometimes even drops audio. i have tried installing a new Divx codec (DivxFusion Beta1) but to no avail. (interesting sidenote: gaming response in regard to mousemovements etc is now excellent, besides this video defect.)
I got the same uneven video playback when exporting an iMovie HD movie (20 mins, high quality, 3,9 GB) to .dv (qt?) format and then trying to play it back with both VLC and QT Player. the same problem has been noticeable in DVD Player and when watching movies (.avi and DVD:s) in VLC. funnily this was not the case with my old Quicksilver G4 933 Mhz and 10.3.9. anyone got a clue?

i am fairly aware of the system workings, though not that very experienced regarding codecs etc.

best regards,
tobias
stockholm

edit: i now have a guess that it might have something to do with the lack of vsync abilities on the TFT screen. suggestions?
 

berving

Registered
hi!

it's me again. I would like to keep this thread open because the tiny little irritating problem still resides.

My own trouble-shooting so far has not been fruitful, but I can inform the curious that neither chaninging user, quitting polling apps or freeing up RAM does the trick. the framedrop every 5-10 seconds is still there! it's one or two frames - i think - enough to cause a choppy playback of, say a car driving past on the screen. and, as i posted earlier, the problem is there in both DVD-player and VLC (0.8.5).

thanks for any help!

/tobias
 

berving

Registered
no, I still haven't had any suggetstions as to why video playback sometimes is a bit choppy. but I suspect the reason for the framdrops is underperformance from either the CPU or the graphics processor or some minor flaw in the graphics card, maybe. but it still is a bit annoying. I think I have run all the tests that I could find in a lot of different software.

thanks,
tobias
 

fryke

Moderator
Staff member
Mod
Um... I think it was a firmware problem with the graphics card. I'd contact Apple about it. Are you running Mac OS X 10.4.7 by now? Did you update any firmware updates that came with Software Update? I _think_ I remember something about the highend iMac having the problem(s) you mentioned...
 
Top