What exactly does the processing thread priority in VDub do?

[KidEgo]

Whenever I'm saving videos in Virtual Dub, I always set the processing thread priority to high assuming it's the best option, but what exactly does it do? Does it really have an effect on the visual/video/audio quality?

[Kariudo]

It doesn't have any effect on the a/v quality. It's just a shortcut for increasing how much of your cpu's time is available for vdub to use (instead of having to track down the process in the task manager, right clicking it and changing the process priority)

You won't really see much (if any) improvement in encode time unless you're doing something that takes a lot of cpu power to run (like...say, Folding @ Home.) If your cpu is bogged down with other stuff, and you change vdub's priority your encode will go faster at the expense of making everything else more sluggish.

Setting the priority too high will make it seem like your computer froze, but that probably won't happen with vdub's little drop down priority box (realtime, and to a lesser extent...high, are not recommended if you change the priority manually in task manager.)

[Scintilla]

If I have encode that I know will take a long time, I typically set this to Idle so that my other programs don't move in slow motion for the duration.