BrainVision Recording Format (BVRF)

BVRF description

An EEG recording consists of four separate files with the same base name:

• Header file (*.bvrh): This is a JSON file containing recording parameters and further meta-information.
• Marker file (*.bvrm): This is a TSV file describing the events that have been collected during the recording.
• Data file (*.bvrd): This is a binary file containing the raw EEG data as well as additional signals recorded along with the EEG.
• Impedance file (*.bvri): This is a TSV file containing impedance values. The file is optional.

For further information refer to the official documentation of our format: BVRF Reference Specification. See also the BVRF License Agreement.

BVRF readers

BVRF files can be read in BrainVision Analyzer from version 2.3.1.8303. Make sure to download the current version here.

For MATLAB^®

Alternatively, you can use the BrainVision BVRF Reader – MATLAB/EEGLAB Plugin, available on the Brain Products GitHub page. With this plugin, you can import data sets directly into MATLAB^® and EEGLAB. Please read the provided documentation on GitHub to learn how to use the plugin.

For MNE-Python/MNELAB

In Python, you can use the new PyBVRF package to load the data directly for your own processing workflows or through its MNE-Python integration. The package is also seamlessly integrated into MNELAB (a standalone graphical user interface for MNE-Python) starting with version 1.3.1. Documentation is available on the PyBVRF GitHub website.

Converting BVRF to BVCDF

This section describes how to convert BrainVision Recording Format (BVRF) to BrainVision Core Data Format (BVCDF).

In certain cases, it may not be feasible to switch from one format to a new one, for example, when doing long-term studies. If necessary, recordings in the new file format can be converted back to BVCDF, which was used in BrainVision Recorder 1. 

In BrainVision Analyzer, this can be done with the “Generic Data” export function that saves to the BrainVision Data Exchange Format (BVDEF 2.0, an extension of the BVCDF). Follow these instructions to convert BVRF to BVCDF:

1. Open the BVRF file in Analyzer.
2. Select the Raw Data node you wish to export.
3. In Analyzer’s Export menu, select Generic Data.
   
   
   
4. To create a set of VHDR, VMKR, and EEG files, follow these settings:
   
   
   
   The Resulting File Names will give you a preview of how these files will be named. 
   Feel free to use the “$h” and “$n” placeholders to prefill the names with contextual information. 
   Follow the rest of the instructions and click on Finish at the last step.​
   
   
   
   
   
   
   
5. If you have followed the steps, the BVRF files are now available also as BVCDF files.

If you have already used the MATLAB- or Python-based readers, you can simply use the corresponding export functions which create BVCDF files by default.

Potential risks when converting from BVRF to BVCDF:

• Impedances from BVRI impedance files are not exported. You will no longer find impedance values under the [Comment] section of the VHDR file. However, corresponding impedance values can still be checked by looking at the human-readable BVRI files.
• Differences between Recorder 1 and Recorder 2 which are not related to the file format: Marker codes no longer use whitespaces to support the combination of a single letter and exactly 3 digits. In BVRF, supported by BrainVision Recorder 2, code and value pairs are introduced instead of full marker descriptions. In Analyzer, both are merged with one single space.
• Unsupported meta data like Physical Channel, Resolution, etc., is missing from the exported BVCDF files.
• For BVRF recordings with multiple participants, not yet supported by Recorder 2, a workaround is applied by adding suffixes based on participant IDs to corresponding channels. Note that BVCDF does not support multiple participant recordings. To separate different participant data into different BVCDF datasets, the channels for each participant can be selected and the suffix removed, e.g., by using the “Edit Channels” transformation and then exported separately.

Demo data

You can download a file containing demo data consisting of visual oddball datasets here: Demo Data - BrainVision Recorder 2 - Visual Oddball .