Feature request: EGI MFF reader for discontinuous files

Code:

raw = mne.io.read_raw_egi(raw_fname)  # already has an average reference

Result:

---------------------------------------------------------------------------
NotImplementedError                       Traceback (most recent call last)
<ipython-input-4-0a72d29f7e68> in <module>()
      1 raw_fname = '/media/oreilly/ETUDE/suj1 session1/signal1.bin'
      2 
----> 3 raw = mne.io.read_raw_egi(raw_fname)  # already has an average reference
      4 events = mne.find_events(raw, stim_channel='STI 014')
      5 

~/python_venv/venv-3.4/lib/python3.5/site-packages/mne/io/egi/egi.py in read_raw_egi(input_fname, montage, eog, misc, include, exclude, preload, channel_naming, verbose)

~/python_venv/venv-3.4/lib/python3.5/site-packages/mne/utils.py in verbose(function, *args, **kwargs)
    726         with use_log_level(verbose_level):
    727             return function(*args, **kwargs)
--> 728     return function(*args, **kwargs)
    729 
    730 

~/python_venv/venv-3.4/lib/python3.5/site-packages/mne/io/egi/egi.py in read_raw_egi(input_fname, montage, eog, misc, include, exclude, preload, channel_naming, verbose)
    166                                  exclude, preload, channel_naming, verbose)
    167     return RawEGI(input_fname, montage, eog, misc, include, exclude, preload,
--> 168                   channel_naming, verbose)
    169 
    170 

~/python_venv/venv-3.4/lib/python3.5/site-packages/mne/io/egi/egi.py in __init__(self, input_fname, montage, eog, misc, include, exclude, preload, channel_naming, verbose)

~/python_venv/venv-3.4/lib/python3.5/site-packages/mne/utils.py in verbose(function, *args, **kwargs)
    726         with use_log_level(verbose_level):
    727             return function(*args, **kwargs)
--> 728     return function(*args, **kwargs)
    729 
    730 

~/python_venv/venv-3.4/lib/python3.5/site-packages/mne/io/egi/egi.py in __init__(self, input_fname, montage, eog, misc, include, exclude, preload, channel_naming, verbose)
    182         with open(input_fname, 'rb') as fid:  # 'rb' important for py3k
    183             logger.info('Reading EGI header from %s...' % input_fname)
--> 184             egi_info = _read_header(fid)
    185             logger.info('    Reading events ...')
    186             egi_events = _read_events(fid, egi_info)  # update info + jump

~/python_venv/venv-3.4/lib/python3.5/site-packages/mne/io/egi/egi.py in _read_header(fid)
     66         info['event_codes'] = np.array(info['event_codes'])
     67     else:
---> 68         raise NotImplementedError('Only continuous files are supported')
     69     info['unsegmented'] = unsegmented
     70     info['dtype'], info['orig_format'] = {2: ('>i2', 'short'),

NotImplementedError: Only continuous files are supported

[Tested with a fresh !pip3 install --upgrade git+https://github.com/mne-tools/mne-python.git install]

This is a feature request so that we can read these files with MNE-Python.

[larsoner]

If the signal is all zeros it’s not totally unreasonable at least. It at least uncompressed okay to ~20MB.

[ViridianForge]

Kind of wandering in here at random, but I’m presently working with Dr. Don Tucker on reading some of these discontinuous .mff files myself.

I can confirm @mmagnuski that an .mff appears to be a folder containing XML describing the data and the signal in .bin files.

Where I’ve started poking around on our end to try and read a discontinuous file is that epochs.xml - which appears to list the start and stop time of each epoch of data in microseconds (waiting on a Philips Neuro programmer to confirm this), and lists the first and last block contained in that epoch.

If sample data would be helpful, I can consult with Dr. Tucker to see if we have clearance to share one of our smaller .mffs (I think in the realm of 250-500MB).