display problem

[tgibbs]

Twice I've had a problem where netTunes client display is mangled. There are a lot of parallel horizontal lines, reminiscent of scan lines on a TV. Other than that, NetTunes and the remote iTunes seemed to function normally. Quitting and restarting the client did not help, but resetting the computer the server resides upon restored the display to normal. Since my server computer is headless, I can't say whether the display on its own monitor is also mangled.

[dnanian]

Well, this kind of thing can happen if the video buffer is being rapidly updated at the same time we're copying data from it. For example, if the visualizer is running, it's writing to the display so quickly that it's hard to capture one "update" before another one has been written to it by the GPU.

During normal operation, though, you shouldn't ever see this kind of thing. Have you tried rebooting the headless server?

[tgibbs]

Originally Posted by dnanian

Well, this kind of thing can happen if the video buffer is being rapidly updated at the same time we're copying data from it. For example, if the visualizer is running, it's writing to the display so quickly that it's hard to capture one "update" before another one has been written to it by the GPU.

During normal operation, though, you shouldn't ever see this kind of thing. Have you tried rebooting the headless server?

Yes, rebooting the server cleared it up both times. Note that this is only two instances in several months, so it isn't a major problem.

[dnanian]

Very strange; it could be that things suddenly slowed down a lot... I'm not really sure, since it's never been reported before. You didn't notice anything else weird?

[tgibbs]

Originally Posted by dnanian

Very strange; it could be that things suddenly slowed down a lot... I'm not really sure, since it's never been reported before. You didn't notice anything else weird?

No, I was able to import a disk at about the normal speed, and while the display was difficult to read, I could see that it was updating at a reasonable rate. Rescaling the NetTunes window did not result in the black lines changing width or merging, so I don't think that they were in the original screen image. I could even see them on the thumbnail in the netTunes Servers window.

[dnanian]

Yes, you'd definitely be able to see them in the thumbnail, which uses the same base data. The problem wasn't on the client, as such -- it was on the server.

I've really never seen this on my own headless server, but I'll definitely keep a look out. Very strange!