How to change the process priority in OBSD?

[Teh Kok How <khteh_(_at_)_willowglen_(_dot_)_com_(_dot_)_my>]

Hi;
	How do I schedule the runtime priority of a userland process in OpenBSD? When 
I run `systat -w 1 vmstat` there are 96% nice time compared to <2% user when 
the system is only running one video encoder program. "nice" is a low 
priority process and this shows that the video encoder is categorized in the 
"nice" low priority group...?

Thanks,
TEH