OpenViBE forum

Posted: **Sun Jan 02, 2022 11:38 pm**

Hi,
I am using OpenVibe as a P300-based BCI. I am able to successfully train the classifier, but receive little to no accuracy and this warning when doing online trials:

Code: Select all

[WARNING] Box <Classifier processor> sends inconsistent chunk dates on output [0] (current chunk dates are [98864994766,101441975143] whereas previous chunk dates were [0,0])
 [WARNING] 'Stimulations' streams should have continuously dated chunks
 [WARNING] Please report to box author and attach your scenario

I get this warning when using the provided P300 speller and magic card examples. I just built the latest code from the git to see if it would be resolved, but it is not.

Posted: **Mon Jan 03, 2022 9:34 am**

Hi,
This warning is not a problem, stimulations date are a little boring to use and often if you don't pay attention to that you have this kind of warning.
Thibaut

Posted: **Mon Jan 03, 2022 9:47 pm**

Hi,
Thanks for the reply. On an older post: viewtopic.php?f=13&t=10179 the similar problem occurred and was fixed. I had the same issue previously, built the latest code that was suggested there, and the problem was solved. I'm not sure why it is occurring again. Is it possible there is another bug with the classifier box?

Posted: **Tue Jan 04, 2022 10:05 am**

Hi,
It's not a real bug but yes there is a problem in the code of the classifier processor. The real problem is the check of consistent date for stimulations. For information all stimulation stream must have chunks that start when the previous ones have finished. but the stimuli are not sent every time.
Thibaut

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