# Writting .mff files into BIDS, problems with write\_raw\_bids **URL:** \ **Category:** Support & Discussions\ **Tags:** mne-bids\ **Created:** [June 5, 2022, 2:53pm UTC](https://mne.discourse.group/t/writting-mff-files-into-bids-problems-with-write-raw-bids/4999 "2022-06-05T14:53:50Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![trevidiann](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/trevidiann/32/1542_2.png) [@trevidiann](https://mne.discourse.group/u/trevidiann)\ **Post date:** [June 5, 2022, 2:53pm UTC](https://mne.discourse.group/t/writting-mff-files-into-bids-problems-with-write-raw-bids/4999/1 "2022-06-05T14:53:50Z")
Hello, new to mne-python and could use some help. I’m currently trying to convert raw data from mff files into BIDS. At the moment I can read in and create a BIDS data structure with raw mff data, but I cannot convert a .bin file (from the mff file) into fif format. **At the moment my program looks like this:** ```python import matplotlib import pathlib import mne import mne_bids matplotlib.use('Qt5Agg') mne.set_log_level('warning') raw_fname = pathlib.Path('subject_data') / 'WM_1_isi0_s1c_20191110_020011.mff' raw = mne.io.read_raw_egi(raw_fname) out_path = pathlib.Path('out_data2/sample_BIDS') #Into which directory the data should go bids_path = mne_bids.BIDSPath(subject='01', session='01', task='WM1 isi0', datatype='eeg', root=out_path) mne_bids.write_raw_bids(raw, bids_path=bids_path, events_data=events, format='FIF', allow_preload=True, event_id=event_id, overwrite=True) ``` **And spits out this error:** ```python --------------------------------------------------------------------------- KeyError Traceback (most recent call last) Input In [6], in () 1 out_path = pathlib.Path('out_data2/sample_BIDS') #Into which directory the data should go 3 bids_path = mne_bids.BIDSPath(subject='01', 4 session='01', 5 task='WM1 isi0', 6 datatype='eeg', 7 root=out_path) #An object that specifies the location of BIDS files ----> 9 mne_bids.write_raw_bids(raw, bids_path=bids_path, events_data=events, format='FIF', allow_preload=True, 10 event_id=event_id, overwrite=True) File :12, in write_raw_bids(raw, bids_path, events_data, event_id, anonymize, format, symlink, empty_room, allow_preload, montage, acpc_aligned, overwrite, verbose) File ~\anaconda3\envs\mne\lib\site-packages\mne_bids\write.py:1668, in write_raw_bids( ***failed resolving arguments*** ) 1663 make_dataset_description(bids_path.root, name=" ", overwrite=False) 1665 _sidecar_json(raw, task=bids_path.task, manufacturer=manufacturer, 1666 fname=sidecar_path.fpath, datatype=bids_path.datatype, 1667 emptyroom_fname=associated_er_path, overwrite=overwrite) -> 1668 _channels_tsv(raw, channels_path.fpath, overwrite) 1670 # create parent directories if needed 1671 _mkdir_p(os.path.dirname(data_path)) File ~\anaconda3\envs\mne\lib\site-packages\mne_bids\write.py:110, in _channels_tsv(raw, fname, overwrite) 108 # get the manufacturer from the file in the Raw object 109 _, ext = _parse_ext(raw.filenames[0]) --> 110 manufacturer = MANUFACTURERS[ext] 112 ignored_channels = IGNORED_CHANNELS.get(manufacturer, list()) 114 status, ch_type, description = list(), list(), list() KeyError: '.bin' ----------------------------------- ``` It appears that write\_raw\_bids is having problems converting .bin files into an fif format, though it could definitely be something else. ---
**Author:** ![richard](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/richard/32/15_2.png) [@richard](https://mne.discourse.group/u/richard)\ **Post date:** [June 7, 2022, 8:23am UTC](https://mne.discourse.group/t/writting-mff-files-into-bids-problems-with-write-raw-bids/4999/2 "2022-06-07T08:23:05Z")
Hello, I’m not familiar with this file format, is that generated by EGI systems? Because there’s currently a pull request to add support for EGI to MNE-BIDS, meaning it’s not yet officially supported: > > > Added EGI as a manufacturer in the eeg\_manufacturers dict for extension '.bin' a…nd '.mff'. This PR closes issue #1005. Also pinging @sappelhoff and @mscheltienne who probably followed this development more closely than I did! Also I think I remember @cbrnr was once dealing with MFF files, but I might be mistaken. Handing out tags here like candy!!! 🍭 In any case, best of luck! Richard ---
**Author:** ![cbrnr](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/cbrnr/32/1409_2.png) [@cbrnr](https://mne.discourse.group/u/cbrnr)\ **Post date:** [June 7, 2022, 8:38am UTC](https://mne.discourse.group/t/writting-mff-files-into-bids-problems-with-write-raw-bids/4999/3 "2022-06-07T08:38:12Z")
Sorry, I never worked with MFF (at least as far as I can remember 😆). ---
**Author:** ![mscheltienne](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/mscheltienne/32/827_2.png) [@mscheltienne](https://mne.discourse.group/u/mscheltienne)\ **Post date:** [June 7, 2022, 12:09pm UTC](https://mne.discourse.group/t/writting-mff-files-into-bids-problems-with-write-raw-bids/4999/4 "2022-06-07T12:09:41Z")
Hello, EEG datasets have to be converted to one of the formats for BIDS. Quoting the [`write_raw_bids` page](https://mne.tools/mne-bids/stable/generated/mne_bids.write_raw_bids.html): > The original file is simply copied over if the original file format is BIDS-supported for that datatype. Otherwise, this function will convert to a BIDS-supported file format while warning the user. For EEG and iEEG data, conversion will be to BrainVision format; for MEG, conversion will be to FIFF. And at the moment, `mne-bids` does not recognize what the `.bin` extension corresponds to and how to convert it to BrainVision format. I’m adding support in the PR linked by @richard but I still have to fix a couple of bugs… I’ll try to find time this week. Best, Mathieu