New version with XDF file support

Hello,

I see XDF file import is on the features roadmap.
How far away is it ?
Is it weeks or rather months ?
Will it read all the streams or eeg only like eeglab ?

Kind regards
Peter

I could work on this in the next few weeks.
The only thing I needed to get started was a user to test it!
Could you share one or a few example files, in order to illustrate everything that you need to be read from these files? (upload the files somewhere and post the download links here)
Thanks

I have some files with 8 channel eeg streamed from OpenBCI and 1 channel streamed from Wiimote (GitHub - labstreaminglayer/App-Wiimote) to to LabRecorder (GitHub - labstreaminglayer/App-LabRecorder: An application for streaming one or more LSL streams to disk in XDF file format.)
I will be happy to test it when the beta is available.
I can do more twisted files if you need (openbci stream + Muse stream + wiimote stream) but this would need to wait until tomorrow.
Where shall I upload the files ?

Regards
Peter

Anything you might think is interesting.
I won't be working on it before the end of next week.

Where shall I upload the files ?

Wherever you'd like. Google drive?

I will prepare a set tomorrow then.

I just uploaded my old file

it contains Muse and Wiimote streams.
When browsing using python's pyxdf module, it shows 1 muse stream, 2 wiimote button streams and 2 wiimote sensors streams

I will later create. file with 2 EEG streams + Wiimote stream + pylsl generated stream as if it was generated by stimulus onset by psychopy

This is latest multi stream file but no Open?BCI yet (will create one today)

The view by pyxdf:

strong text

The use case of multiple streams (in my case at least) would be seeing selected channels (including non=EEG channels - wiimote and pylsl) so the users can focus their analysis for example on fragment between 2 wiimote markers or after a particular pylsl marker.
I do not see a use for the wiimote sensor data channel yet and am not sure how they could be presented in =Brainstorm GUI so at this stage I am ok for them to be ignored.

Please let me know when/how I can help any further here.

Regards
Peter

I added a basic support for XDF files in Brainstorm, but it probably requires additional work to get the events right. Update Brainstorm to get this commit:

The problem I have with your file "sub-P001_ses-S001_task-Default_run-002_eeg.xdf" is that the time stamps do not match in the different streams.

Stream 'WiimoteMarkers1':
    first_timestamp: '937859.846525154'
     last_timestamp: '937885.990850207'

Stream 'Muse':
    first_timestamp: '1642606156.35645'
     last_timestamp: '1642606209.1935'

How are we supposed to add the Wiimote markers as events available in the EEG recordings in Brainstorm?

Thank you Francois,

Let me dig here a bit.
I will be back

Regards
Peter

Yes, this obviously does not make any sense.
It seems to be derived from the "created_at" time which is a time since device reboot according to:

I will flag this to the developer and will be back.

Regards
Peter

Just created:
GIT HUB /labstreaminglayer/App-Wiimote/issues/1

Regards
Peter

My previous post was hidden as it contained a link to github:

Yes, this obviously does not make any sense.
It seems to be derived from the "created_at" time which is a time since device reboot according to:
"git hub issue 28"

I will flag this to the developer and will be back.

Regards
Peter

I just did a bit of digging.
May I ask how were the timestamps implemented ?
Were they just taken from the timestamps list (in python - the time_stamps list) ?

data, header = pyxdf.load_xdf(filename='/Users/windy/wiimote_pylsl_muse_test.xdf',verbose=False)
data[0]["time_stamps"]

It seems that to get the time synched between different streams implementation needs to consider the
time offset (i.e in python - >

data, header = pyxdf.load_xdf(filename='/Users/windy/wiimote_pylsl_muse_test.xdf',verbose=False)

data[0]['footer']["info"]["clock_offsets"][0]["offset"][0]["time"][0]
data[0]['footer']["info"]["clock_offsets"][0]["offset"][0]["value"][0]

Peter

May I ask how were the timestamps implemented ?
Were they just taken from the timestamps list (in python - the time_stamps list) ?

These are simply the time stamps read by the library.

It seems that to get the time synched between different streams implementation needs to consider the
time offset

Unfortunately I have no idea what to do with these clock_offsets...

[streams, fileheader] = load_xdf('wiimote_pylsl_muse_test.xdf');

% Stream 2: EEG
streams{2}.info.name        % 'Muse'
streams{2}.time_stamps(1)   % '1662538492.337204'
streams{2}.time_stamps(end) % '1662539106.378531'

streams{2}.info.clock_offsets.offset{1} 
     time: '689177.036504109'
    value: '935403.2126102761'

streams{2}.info.clock_offsets.offset{111} 
     time: '689787.5735895969'
    value: '935403.212608692'


% Stream 3: Wiimote
streams{3}.info.name        % 'WiimoteMarkers1'
streams{3}.time_stamps(1)   % '1624585.380932'
streams{3}.time_stamps(end) % '1625125.514074'

streams{3}.info.clock_offsets.offset{1} 
     time: '1624580.249122672'
    value: '-1.401640474796295e-05'

streams{3}.info.clock_offsets.offset{111}
     time: '1625190.782890341'
    value: '2.137967385351658e-06'

I am just doing further experiments with 8 channels OpenBCI + Wiimote + Pylsl (will upload the file soon if still needed)
I read the XDF into EEBLab and am getting all channels, Pylsl and wiimote markers synched in one graph.
I found the matlab examples in labstreaminglayer that use the offset synchronisation

There is github /labstreaminglayer/liblsl-Matlab repo
and the load_xdf.m matlab script:
github /xdf-modules/xdf-Matlab

I guess this script can be just included in the Brainstorm distro.

Regards
Peter

I'm sorry, I don't know where to start from or what to look for in these code bases.
Please describe what you are doing with more details: full code and step by step screen captures, including for what it means to "read the XDF into EEBLab" (I am not familiar with EEGLAB).

The function load_xdf.m from xdf-modules/xdf-Matlab is the one I've been using:

Please feel free to open PR to fix the XDF reader directly on the Brainstorm github repo:

It seems that my Muse+Wiimote xdf file was somehow corrupted.
The 3 stream xdf with OpenBCI + Wiimote + PyLSL does show all 3 streams in Brainstorm.
Thank you for your work.

So everything is working as expected?
No need to make any change to the current implementation?