[FieldTrip] Real-time processing

[Mariana Branco]

Hello,

I am new in the BCI research field, and I am starting to implement an online BCI system using the Fieldtrip toolbox to detect ERD/ERS features. I already did two offline experiments using this toolbox, but now I am having some doubts about how to adapt the offline signal processing functions into real-time; I started by simulating real-time data from a file. 
My questions are:
1) To process the data real-time using ft_preprocessing is it first necessary to define trials (with ft_definetrial)? If so, how can I define the trial if it is real-time?
2) Is it possible to still use the function ft_preprocessing and ft_resampledata in real-time with the same specifications of offline procedure?
3) When simulating data stream (with two matlab sessions) the function ft_realtime_powerestimate(cfg) reports an error related to the "arg 3 (overlap)" on the welch's method. How can I correct this?
4) Also, for synchronous/triggered data analysis it is available the function ft_realtime_average. Is it possible to explain how can this example function be used for implementation of my own feature processing and extraction function. Does it preprocess the data in an alternative way to ft_preprocessing?

I am sorry for all the questions.
Regards,

Mariana Branco