[FieldTrip] Brainvision recorder RDA

[Bora Cebeci]

Hi,

I want to use the Fieldtrip functions for real-time data processing. I'm
testing the delay. Neither rda2ft.exe nor ft_realtime_brainampproxy.m is
working properly. If you don't get an event, ft_realtime_brainampproxy.m
can be usable.
I found three messages about Brain Vision Recorder in the mail list. I have
similar problems as mentioned in those messages.

1) I think that using rda2ft.exe is faster than
ft_realtime_brainampproxy.m, so finding a solution for rda2ft.exe problem
will be enough. I have the same error message as *Casper van Heck.
Casper  *said:
"

>* When running rda2ft.exe (with the parameters localhost and 51244) it does seem to connect; it shows the list of channels (all channels), their resolution, and their names, and some other assorted stuff. However, it then says:
*>* "Unrecognized packet type (10000), has size 24 - exiting"*

"
My parameters : " rda2ft.exe localhost 51234"
and I tried it in a different PC: " rda2ft.exe 10.1.54.160 51234"
I got the same error message.


2) Secondly, I tried to use ft_realtime_brainampproxy.m, but I cannot use
it efficiently. When an event occurs, buffering freezes and there is no
error message.

I have a bad solution for this problem. I'm stopping the program by
"Ctrl+C" then I start it again.
Meanwhile I measured 179ms delay (average of 45 trials), it is really big ??


3) Even the above problem is solved, the events cannot read. Khalid
mentioned before about this problem. I couldn't find the reading code for
events in the ft_realtime_brainampproxy.m file. Here is the related part of
the code:

 % convert the RDA message into data and/or events
  dat   = [];
  event = [];

  if msg.nType==2 && msg.nPoints>0
    % FIXME should I apply the calibration here?
    dat = msg.nData(chanindx,:);
  end

  if msg.nType==4 && msg.nPoints>0
    % FIXME should I apply the calibration here?
    dat = msg.fData(chanindx,:);
  end

  if (msg.nType==2 || msg.nType==4) && msg.nMarkers>0
    % FIXME convert the message to events
  end

The variable 'event' doesn't get any value here. So by using ft_read_event
function , you get an empty vector.

Thanks


-- 
Bora Cebeci
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