video frames aren't synched to vblank

[Bogdan Butnaru]

Binary package hint: nvidia-glx-180

Hello! I'm running up-to-date Jaunty on a machine with an nVidia 9600GT card. It uses the nvidia-glx-180 binary driver. My screen is an HP LP2475w.

Things mostly work great, except for a tiny annoying issue: On some movies I get visible streaking in the upper part of the screen. I looks as if the frames aren't flipped when they should be, on vblank.

(I've got __GL_SYNC_TO_VBLANK is always set, enabled it in nvidia-settings, and in Compiz.) This isn't a performance problem, for instance it happens repeatedly with some low-resolution movies, but never on some HD movies.

It's mostly visible when there's some horizontal panning, and I'm not sure if it happens all the time and it's just less noticeable then.

This happens with both XVideo and VDPAU outputs, in all video players I've tried. Also, both in full-screen and windowed mode.

I'm attaching a screenshot; it's not exactly what I see on the screen, but it gives a good idea of what it looks like. (Warning, it's a pretty big file.) What I see looks exactly like the part marked “A” in the picture, and in the same spot, as far as I can tell visually. However, I never noticed streaking in the parts marked “B”, so I assume those are caused by the screenshot. (I suppose that's another bug in itself.)

Any idea how I might diagnose this further?

[lspci]
00:00.0 Host bridge [0600]: Intel Corporation 4 Series Chipset DRAM Controller [8086:2e20] (rev 03)
     Subsystem: ASUSTeK Computer Inc. Device [1043:82d3]
01:00.0 VGA compatible controller [0300]: nVidia Corporation G94 [GeForce 9600 GT] [10de:0622] (rev a1)
     Subsystem: Giga-byte Technology Device [1458:3488]

[Bryce Harrington (bryce)]

Hi bogdanb,

Thanks for including an image to demonstrate the issue. Could you also please attach the output of `lspci -vvnn`, and attach your /var/log/Xorg.0.log or Xorg.0.log.old file from after reproducing this issue. If you've made any customizations to your /etc/X11/xorg.conf please attach that as well.

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[Bogdan Butnaru (bogdanb)]

Hi Bryce's bot!

This doesn't look like a transient bug(*), so I doubt the logs would help, but I include them in case there's some hint there.

(*: I didn't mention this clearly before, but the streaking seems dependent on the video file: I have a few films I always get streaking on, and a few where I never noticed. I get this streaking on other videos, but if I don't watch them all the time it's harder to tell if it's random or regular. It's regular on at least some videos.)

I also included xorg.conf; note however that I've been doing lots of changes to it during the last couple of months, and the streaking has been with mee all this time.

[Stephen Warren (srwarren)]

For VDPAU output, this should be fixed in recent 185.18.* beta drivers. It won't be fixed in the 180.* release series.

[Bogdan Butnaru (bogdanb)]

For the record, I get the exact same tearing behavior I described originally with 180.* drivers (even earlier ones IIRC) and with 185.18.10.

Also, with mplayer at least it happens similarly with VDPAU and with other output methods (xv, x11 and opengl). The tearing is not exactly similar in that it occurs more visibly (I think because of worse processor usage) and not exactly in the same spot (it's still in the top part of the frame, but not as constant in position as for VDPAU).

[Bryce Harrington (bryce)]

I've posted a new version of the -nvidia driver to our xorg-edgers PPA,
would you mind testing it either on Jaunty or Karmic and see if it
resolves this bug?

Get nvidia-graphics-drivers-180 - 185.18.14 here:

  https://edge.launchpad.net/~xorg-edgers/+archive/ppa

[Bryce Harrington (bryce)]

We're closing this bug since it is has been some time with no response from the original reporter. However, if the issue still exists please feel free to reopen with the requested information. Also, if you could, please test against the latest development version of Ubuntu, since this confirms the bug is one we may be able to pass upstream for help.