Timestamp in the lab streaming layer
Hi All,
I have been using LSL via pylsl with the cyton+daisy of OpenBCI. Based on the example brainflow_lsl.py, I assign a timestamp by outlet_timestamp = local_clock(); outlet.push_chunk(mychunk, outlet_timestamp).
I also execute the inlet in the same computer and get the chunk by sample, inlet_timestamp = inlet.pull_sample(). I think inlet_timestamp should equals outlet_timestamp, but it is not. Thus, I have to misunderstand something.
I will be appreciated if anybody could please elucidate me.
Best,
vattha
P.S.
- brainflow_lsl.py is from https://github.com/OpenBCI/OpenBCI_GUI/blob/master/Networking-Test-Kit/LSL/brainflow_lsl.py#L29
Comments
LSL can be more complicated than other networking protocols. If you are pushing chunks, I think you should also receive chunks. LSL also automatically calculates timestamps of data that has not been explicitly timestamped (ex samples 1-5 in a chunk where sample 1 has a stamp from the local clock).