General Data Format for Biomedical Signals
The General Data Format for Biomedical Signals is a scientific and medical data file format. The aim of GDF is to combine and integrate the best features of all biosignal file formats into a single file format. GDF v1 uses a binary header, and uses an event table. GDF v2 added fields for additional subject-specific information (gender, age, etc.), and utilizes several standard codes (for storing physical units and other properties).
GDF is used mostly in brain–computer interface research; however, GDF provides a superset of features from many different file formats, it could be also used for many other domains.
The free and open source software library BioSig provides implementations for reading and writing of GDF in Octave/Matlab and C/C++. A lightweight C++ library called libGDF is also available and implements version 2 of the GDF format.
The binary nature of the meta-information might not be suitable for all applications. Therefore, a new format called XDF was developed with the aim to provide a flexible and extensible format for all kinds of data streams, but in particular for biosignals.