LSL (low-level)

If the high-level API is not sufficient, the low-level API interface directly with liblsl, with a similar API to pylsl.

Compared to pylsl, mne_lsl.lsl pulls a chunk of numerical data faster thanks to numpy. In numbers, pulling a 1024 samples chunk with 65 channels in double precision (float64) to python takes:

• 4.33 ms ± 37.5 µs with pylsl default behavior

• 471 ns ± 1.7 ns with pylsl using a ndarray as dest_obj to prevent memory re-allocation

• 268 ns ± 0.357 ns with mne_lsl.lsl which uses numpy.frombuffer() under the hood

More importantly, pylsl default behavior pulls a chunk in linear time O(n), scalings with the number of values; while mne_lsl.lsl pulls a chunk in constant time O(1). Additional details on the differences with pylsl and mne_lsl can be found here.

StreamInfo	Base Stream information object, storing the declaration of a stream.
StreamInlet	An inlet to retrieve data and metadata on the network.
StreamOutlet	An outlet to share data and metadata on the network.
library_version	Version of the binary LSL library.
protocol_version	Version of the LSL protocol.
local_clock	Obtain a local system timestamp in seconds.
resolve_streams	Resolve streams on the network.