suggest_thread_priority
int32 suggest_thread_priority(uint32 task_flags = B_DEFAULT_MEDIA_PRIORITY,
int32 suggest_thread_priority(uint32 what, int32 period, bigtime_t jitter,
SetPriority( suggest_thread_priority( B_VIDEO_RECORDING, 60, 8000, 8000 ));
suggest_thread_priority(B_STATUS_RENDERING), this);
SetPriority(suggest_thread_priority(priority));
SetPriority(suggest_thread_priority(priority));