Crate fiff 

FIFF (Functional Imaging File Format) Parser

✅ COMPREHENSIVE METADATA PARSER - Production-ready parser for Neuromag/Elekta MEG data with extensive metadata support. See IMPLEMENTATION_STATUS.md for full details.

This module provides a pure Rust implementation of the FIFF file format parser, based on MNE-Python’s implementation. FIFF is the native format for Neuromag/Elekta MEG systems and is widely used in MEG/EEG data analysis.

For advanced MEG analysis or matrix operations, use MNE-Python instead.

Public API

Core Functions

• open_fiff: Open and parse a FIFF file
• MeasInfo::read: Extract measurement metadata

Data Structures

• ChannelInfo: Channel information (name, type, calibration, etc.)
• MeasInfo: Measurement metadata (channels, sampling rate, etc.)
• TreeNode: FIFF directory tree structure
• Tag: FIFF tag (kind, type, data)
• DirEntry: FIFF directory entry

Constants

All FIFF constants are re-exported from the constants module, including:

• Block types (FIFFB_*)
• Tag kinds (FIFF_*)
• Data types (FIFFT_*)
• Channel types (FIFFV_*_CH)

Helper Functions

• channel_type_name: Get human-readable channel type name
• is_data_channel: Check if a channel type is a data channel
• type_size: Get byte size for a FIFF data type

Re-exports

pub use tag::DirEntry;

pub use tag::Tag;

pub use tree::build_tree;

pub use tree::dir_tree_find;

pub use tree::TreeNode;

pub use constants::*;

Modules

constants

tag

tree

Structs

ChannelInfo

Channel information parsed from FIFF_CH_INFO_STRUCT (96 bytes)

Compensation

CTF (Canadian Thin Films) MEG Compensation CTF systems use reference channels to cancel environmental noise. Compensation matrices transform reference channel data to remove artifacts.

CoordTrans

Coordinate Transformation Transforms points between coordinate frames (device, head, MRI, etc.)

MeasInfo

Measurement info from FIFF file

Projection

SSP/Signal Space Projection operator Used for artifact removal (e.g., eye blinks, heartbeat, environmental noise)

Functions

open_fiff

Open and parse a FIFF file