Tegra Multimedia API

Hello! I am developping a multimedia application on the TX1 platform.
Because of some problems, will use Tegra Multimedia API directly instead of GStreamer framework.
When examining its sample codes for video encoding (samples/01_video_encode/*.cpp), some questions
have occured. That sample code accepts many coding options, for example ‘-br’, ‘-p’, ‘-rc’ and so on. Some options have been understood but others not. Especially ‘-vbs’ and ‘-nrf’ options.
Although I read the API documents related to the options, it didn’t help.
What purposes do the two options exist for ? Please help…

Sorry, this post moved to the section for Jetson TX1.