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AbstractFormatReader

Namespace: BIDSLIB  ·  Library: BIDS Library

#include <bids/bids_abstract_format_reader.h>

class BIDSLIB::AbstractFormatReader

The AbstractFormatReader class provides a common interface for reading raw neurophysiology data from various file formats (EDF, BrainVision, etc.) used in BIDS datasets.

Subclasses implement format-specific parsing and expose the data uniformly as FIFF structures.

src/examples/ex_bids/main.cpp
std::unique_ptr<AbstractFormatReader> edf = BidsRawData::createReader(".edf"); // or construct EDFReader directly
const bool edfOpen = edf->open(BIDSPath(root, "02", "01", "rest", "eeg", "eeg", ".edf").filePath());
const FIFFLIB::FiffInfo edfInfo = edf->getInfo();
const MatrixXf edfHead = edf->readRawSegment(0, 201);

Inheritance​

Public Methods​

~AbstractFormatReader()​

Virtual destructor.

open(sFilePath)​

Open and parse the file header.

Must be called before reading data.

Parameters:

  • sFilePath : const QString & Absolute path to the primary data file.

Returns:

  • bool — True if the file was opened and parsed successfully.

getInfo()​

Return measurement metadata as FiffInfo.

Returns:

  • FiffInfo — FiffInfo populated from the native format header.

readRawSegment(iStartSampleIdx, iEndSampleIdx)​

Read a segment of raw data.

Parameters:

  • iStartSampleIdx : int First sample index (0-based, inclusive).

  • iEndSampleIdx : int Last sample index (0-based, exclusive).

Returns:

  • Eigen::MatrixXf — Matrix of shape (n_channels x n_samples) with calibrated physical values.

getSampleCount()​

Return total number of samples across the recording.

Returns:

  • long — Number of samples per channel in the whole recording.

getFrequency()​

Return the sampling frequency in Hz.

Returns:

  • float — Sampling frequency in Hz.

getChannelCount()​

Return the number of measurement channels.

Returns:

  • int — Number of measurement channels (rows returned by readRawSegment).

toFiffRawData()​

Convert the entire dataset to a FiffRawData structure.

Returns:

  • FiffRawData — FiffRawData populated with info, calibrations, and sample bounds.

formatName()​

Return a descriptive name for the format (e.g.

"EDF", "BrainVision").

Returns:

  • QString — Human-readable format name.

supportsExtension(sExtension)​

Check whether this reader can handle the given file extension.

Parameters:

  • sExtension : const QString & File extension including dot (e.g. ".edf", ".vhdr").

Returns:

  • bool — True if this reader supports the extension.

Example​

Used in examples​

ex_bids​

BIDS library: paths, sidecar TSVs, BrainVision/EDF readers and a raw-data round trip.

src/examples/ex_bids/main.cpp, line 136
std::unique_ptr<AbstractFormatReader> edf = BidsRawData::createReader(".edf"); // or construct EDFReader directly
const bool edfOpen = edf->open(BIDSPath(root, "02", "01", "rest", "eeg", "eeg", ".edf").filePath());
const FIFFLIB::FiffInfo edfInfo = edf->getInfo();
const MatrixXf edfHead = edf->readRawSegment(0, 201);
// mne.io.read_raw_edf: 25 channels at 128 Hz, 1228 samples, first channel "EEG Fp1"; data[3, 200] = 0.1757724
ok &= expect(edfOpen && dynamic_cast<EDFReader*>(edf.get()) != nullptr && edf->formatName() == "EDF" && edfInfo.nchan == 25 && edfInfo.ch_names.first() == "EEG Fp1" && edf->getSampleCount() == 1228 && near(edfHead(0, 0), 0.17594066, 1e-5) && near(edfHead(3, 200), 0.17577240650034331, 1e-5),
             QString("EDF: %1 channels, %2 samples, (3,200) = %3 match mne").arg(edfInfo.nchan).arg(edf->getSampleCount()).arg(edfHead(3, 200), 0, 'g', 8));

Authors of this file​