IEEG-Portal uses the MEF format:
The IEEG-Portal stores all electrophysiology datasets using the Multiscale Electrophysiology File format (MEF). This file-format enables us to store high-bandwidth multichannel data using lossless compression. On average, this file-format gives space savings of around 90%. The MEF library is open source and available on Github. This repository also contains methods to convert files to MEF from other file formats as well as more documentation. We encourage users to try out the MEF-Format for their own datasets.
View the MEF Specification:
MEF-Format specification
The repository can be accessed at:
https://github.com/benbrinkmann/mef_lib_2_1
Brinkmann BH, Bower MR, Stengel KA, Worrell GA, Stead M. “Large-scale electrophysiology: acquisition, compression, encryption, and storage of big data”. J Neurosci Methods. 2009;180(1):185-192.
Bower MR, Stead M, Brinkmann BH, Dufendach K, Worrell GA. “Metadata and Annotations for Multi-scale Electrophysiological Data.” Conf Proc IEEE Eng Med Biol Soc. 2009; 2009:2811–2814.