GB-PVR Background task priority > High?

[Trevor]

OK, so I got home after work today to check how my PVR recordings worked for the day. All of them seemed fine except for one, which had moments that felt like there was some crazy fast forwarding going on.

Since it only happened to one recording, I had a suspicion of what happened.

Me: Kids, what were you doing around 4:45, just before I got home?
Kid: Playing Sims 2...

I'm guessing that if you have an app eating up all the CPU cycles, then GB-PVR (or rather my PVR-150) can have some lossy data collection. I'm running a Sempron 2500+ with 512MB of RAM for reference.

Is there any way to remedy this? I'm going to change the priority of the GBPVRTray.exe to "High" using the Windows Task Manager as an experiment, but even if this does work the process won't start up in high priority after a reboot.

Does anyone have any ideas about this? Experience with mangled recordings while another intense CPU process is going on in the foreground?

[Trevor]

I can verify this now. The Sims 2 + GB-PVR means a corrupted video stream, with "skips" of about a half second duration sprinkled into the stream, looking like "fast forwarded" sections

When my computer is recording, it looks like it's using 2% of the CPU, spiking occasionally at 11%. I'm guessing that when a 99% CPU app like The Sims2 is running.

I also realized that the taskbar app and the recording thread are seperate, so setting a high priority on the taskbar app doesn't seem to modify the priority of the recording thread (**Not verified, need to test this next)

So would this need to be changed at the GB-PVR level, launching the recording thread with a high priority. Would this be something that I'd need to feature request?

(Uninstalling the Sims 2 will make my kids upset and isn't an option...

[Trevor]

Haha! I solved this with a hack.

This is tricky because the GBPVRRecordingService.exe process is owned by SYSTEM and can't be easily changed with Task Manager.

If you up the process priority with either an app (http://www.beyondlogic.org/solutions/pro...ssutil.htm) or a hack (http://weblogs.asp.net/rosherove/archive...1186.aspx), you can change the process priority. I set the priority to "High" and tried recording a show and running The Sims 2 again. And it worked! The Sims suffered some "jitter" effects when CPU usage spiked to 100%, but not the recorded program, which is exactly the effect I was going for.

I'm now going to write this up as a feature request.

[capone]

No love getting either to work, but I know what you're saying. I always wondered about that, and it's cool to see it proven.

What method did you use? Since the box is pvr only, it'd be nice to officially dedicate it.

[Trevor]

My box is not PVR only, but I still think it makes sense in a PVR context.

using the first link, i've simply created a bat file with the line:

@process -p GBPVRRecordingService.exe high

(along with extracting process.exe from the download on that site.

The second site details a debugging tool called ntsd that when comboed up with taskmgr allows you to change the priority even for System processes:

cmd
ntsd taskmgr
qd
(task manager pops up, and you can change the process priority without an error)

P.S., I upgraded to the latest release (the one mislabeled as a pre-release, but not the very most recent drivers), seems OK so far...