VSync with fglrx

[einal]

Hi,

I'm running XBMC on a Shuttle X100 with an Radeon Mobility X1400 and the Catalyst 8.02 driver from AMD/ATI. The tearing in videos is starting to drive me mad so I started looking into the reason. Even with Sync To Vertical Blank turned on in the options I still get tearing and these lines from the log:

18:14:49 T:3067430720 M:458547200 INFO: GL: Enabling VSYNC
18:14:49 T:3067430720 M:458547200 WARNING: EnableVSync - glXSwapIntervalSGI failed
18:14:49 T:3067430720 M:458547200 WARNING: EnableVSync - glXSwapIntervalMESA failed
18:14:49 T:3067430720 M:458547200 WARNING: EnableVSync - glXGetVideoSyncSGI failed, glcontext probably not direct
18:14:49 T:3067430720 M:458547200 ERROR: GL: Vertical Blank Syncing unsupported

I've been googling this for the past couple of days, but all I could really find was a few comments from a few years back complaining that the fglrx driver didn't support glXSwapIntervalSGI. Now I know the ATI drivers haven't been up to snuff these last years, but this is kind of ridicilous. Catalyst Control Center has an option to enable VSync and I've set that to always on without any results.

Is there anybody that knows if this is basically a fault in the driver or is there maybe some other way to implement VSync in OpenGL code for ATI cards that I haven't found? And what on does the vsync option in Catalyst Center actually enable?

einar.

[d4rk]

If you've enabled the option in your driver settings, then it shouldn't tear no matter if it is enabled/disabled inside XBMC. Have you tried disabling Vsync support inside XBMC? Also, if you're using more than one monitor, it might be syncing to the wrong one.

EDIT: You shouldn't need to but did you try restart X after making the driver setting changes?

[einal]

I've tried enabling/disabling vsync in xbmc, enabling/disabling the Sync option in Catalyst Center and restarting X but I still get the tearing.

The strange thing is that it's not a single horizontal line like I would think with screen tearing. The line looks something like this:

____
\__________

I also get the tearing in mplayer with -vo xv.

[einal]

I found this bit from the release notes of fglrx 8.1 (https://a248.e.akamai.net/f/674/9206/0/www2.ati.com/drivers/linux/catalyst_81_linux.html):

Diagonal tearing may be noticed when playing a video file using a video player that utilizes the XVideo extension

So I guess I'll have to wait for fixed drivers from AMD or try the driver from the Ubuntu repo again.

[einal]

I thought I'd add here that AMD released Catalyst 8.3 (http://ati.amd.com/support/drivers/linux/previous/linux-rf-cat83.html) on 3/5 and according to them one of the issues it fixes is "Diagonal tearing will no longer be noticed when playing a video file using a video player that utilizes the XVideo extension".

Well, I installed the new driver, made sure VSync was enabled in Catalyst Center and started up XBMC. It's true that the strange diagonal tearing is gone, instead I get a constant horizontal tear near the top of the screen. Turning of VSync in the driver is actually an improvement although I do get some tearing in fast scenes.

I sure hope AMD gets their shit together and fixes this once and for all, but I'm not holding my breath.

[BLKMGK]

Slap a cheap fanless 8500 in there and call it a day. NVIDIA just plain works. <shrug>

[brw02005]

Well AMD did release their grpahics driver specs to open source probably in a few years they will have better linux support than nvidia (still believe it when I see it). As for nvidia yeah they work but good luck getting standby to work. I got hibernation working with tips and tricks but standby is a no go.

Took me two weeks to figure out how run compiz with dual screen on ati on my girlfriends 200M chipset in her notebook. Turns out the chipset is so underpowered it can only support 1024X768 on two screens with compiz otherwise it would bomb. Still can't get the dam settings to save from the ati catalyst control center either I just tell her to redo it when she restarts. The new drivers better but still need some work.