Question on a red status on bottom bar

[milamber]

I'm giving Blue Iris a test, I noticed there's a red indication on the bottom status bar. I can't find any information on the help menu. Can someone explain it to me?

 

[fenderman]

See this thread http://www.ipcamtalk.com/showthread.php?1291-More-trying-to-understand-BI&highlight=headroom