Limiting Framerate

Is there any way to limit the framerate of the NvIFR H264 encoder?

I’ve tried setting the dwFrameRateDen and dwFrameRateNum to 1 and 30, but I still seem to be getting video back at 60 fps. I’m using WaitForSingleObject(g_EncodeCompletionEvent, INFINITE) in my thread that calls NvIFRGetStatsFromH264HWEncoder(params).

Should I just be sleeping my own thread?