xdf #

Read and write XDF (Extensible Data Format) recordings, the file format of LabRecorder and the Lab Streaming Layer. Pure Dart; works on all platforms, including the web.

Just want to look at an XDF file? Open it in LSL Viewer, a free XDF file viewer built on this package. It runs in the browser (the file isn't uploaded) and on the desktop.

• loadXdf(bytes): a whole file in memory, like pyxdf's load_xdf: clock synchronisation (robust fit, clock reset detection), jitter removal and effective rates, with pyxdf's algorithms and defaults. Tested against pyxdf 1.17.5 on the xdf-modules example files (see test/fixtures).
• XdfFile.open(ByteSource): large files without loading them: one indexing pass builds summary pyramids per regular stream (from signal_core), so overviews, zooming and filtered windows are fast; markers and irregular streams are kept in memory. A stream without breaks gets exactly pyxdf's time stamps.
• XdfWriter: write files as data comes in (headers, samples, clock offsets, boundaries, footers), e.g. to record LSL streams.
• readChunks, readSamples: the raw chunks.

final rec = loadXdf(File('session.xdf').readAsBytesSync());
for (final s in rec.streams) {
  print('${s.info.name}: ${s.length} samples at ${s.effectiveRate} Hz');
}

Coming from Python: loadXdf corresponds to pyxdf's load_xdf and gives the same results on the reference files. XdfFile is for files too large to load at once.