def __init__(self, info: pylsl.StreamInfo, plt: pg.PlotItem):
super().__init__(info)
# calculate the size for our buffer, i.e. two times the displayed data
bufsize = (2 * math.ceil(info.nominal_srate() * plot_duration), info.channel_count())
self.buffer = np.empty(bufsize, dtype=self.dtypes[info.channel_format()])
empty = np.array([])
# create one curve object for each channel/line that will handle displaying the data
self.curves = [pg.PlotCurveItem(x=empty, y=empty, autoDownsample=True) for _ in range(self.channel_count)]
for curve in self.curves:
plt.addItem(curve)
def channel_names(stream_info: pylsl.StreamInfo) -> List[str]:
"""Extracts the channel names from the LSL Stream metadata."""
channels = []
if stream_info.desc().child("channels").empty():
return channels
channel = stream_info.desc().child("channels").child("channel")
for _ in range(stream_info.channel_count()):
channel_name = channel.child_value("label")
channels.append(channel_name)
channel = channel.next_sibling()
return channels
def __init__(self, info: pylsl.StreamInfo):
# create an inlet and connect it to the outlet we found earlier.
# max_buflen is set so data older the plot_duration is discarded
# automatically and we only pull data new enough to show it
# Also, perform online clock synchronization so all streams are in the
# same time domain as the local lsl_clock()
# (see https://labstreaminglayer.readthedocs.io/projects/liblsl/ref/enums.html#_CPPv414proc_clocksync)
# and dejitter timestamps
self.inlet = pylsl.StreamInlet(info, max_buflen=plot_duration,
processing_flags=pylsl.proc_clocksync | pylsl.proc_dejitter)
# store the name and channel count
self.name = info.name()
self.channel_count = info.channel_count()
def read_channel_labels_from_info(info: lsl.StreamInfo):
channels_tag = info.desc().child('channels')
if channels_tag.empty():
return None
else:
# TODO: this is hard to read. Write a generator for children with a given name in helpers
labels = list()
types = list()
single_channel_tag = channels_tag.child(name="channel")
for channel_id in range(info.channel_count()):
labels.append(single_channel_tag.child_value(name='label'))
types.append(single_channel_tag.child_value(name='type'))
single_channel_tag = single_channel_tag.next_sibling(
name='channel')
return labels, types
def main():
# create a new StreamInfo object which shall describe our stream
info = StreamInfo("MetaTester", "EEG", 8, 100, "float32", "myuid56872")
# now attach some meta-data (in accordance with XDF format,
# see also https://github.com/sccn/xdf/wiki/Meta-Data)
chns = info.desc().append_child("channels")
for label in ["C3", "C4", "Cz", "FPz", "POz", "CPz", "O1", "O2"]:
ch = chns.append_child("channel")
ch.append_child_value("label", label)
ch.append_child_value("unit", "microvolts")
ch.append_child_value("type", "EEG")
info.desc().append_child_value("manufacturer", "SCCN")
cap = info.desc().append_child("cap")
cap.append_child_value("name", "EasyCap")
cap.append_child_value("size", "54")
cap.append_child_value("labelscheme", "10-20")
# create outlet for the stream
outlet = StreamOutlet(info)
# (...normally here one might start sending data into the outlet...)
# === the following could run on another computer ===
# first we resolve a stream whose name is MetaTester (note that there are
# other ways to query a stream, too - for instance by content-type)
results = resolve_stream("name", "MetaTester")
# open an inlet so we can read the stream's data (and meta-data)
inlet = StreamInlet(results[0])
# get the full stream info (including custom meta-data) and dissect it
info = inlet.info()
print("The stream's XML meta-data is: ")
print(info.as_xml())
print("The manufacturer is: %s" % info.desc().child_value("manufacturer"))
print("Cap circumference is: %s" %
info.desc().child("cap").child_value("size"))
print("The channel labels are as follows:")
ch = info.desc().child("channels").child("channel")
for k in range(info.channel_count()):
print(" " + ch.child_value("label"))
ch = ch.next_sibling()
time.sleep(3)
cap.append_child_value("labelscheme", "10-20")
# create outlet for the stream
outlet = StreamOutlet(info)
# (...normally here one might start sending data into the outlet...)
# === the following could run on another computer ===
# first we resolve a stream whose name is MetaTester (note that there are
# other ways to query a stream, too - for instance by content-type)
results = resolve_stream("name", "MetaTester")
# open an inlet so we can read the stream's data (and meta-data)
inlet = StreamInlet(results[0])
# get the full stream info (including custom meta-data) and dissect it
info = inlet.info()
print("The stream's XML meta-data is: ")
print(info.as_xml())
print("The manufacturer is: %s" % info.desc().child_value("manufacturer"))
print("Cap circumference is: %s" %
info.desc().child("cap").child_value("size"))
print("The channel labels are as follows:")
ch = info.desc().child("channels").child("channel")
for k in range(info.channel_count()):
print(" " + ch.child_value("label"))
ch = ch.next_sibling()
time.sleep(3)
ch.append_child_value("label",label)
ch.append_child_value("unit","microvolts")
ch.append_child_value("type","EEG")
info.desc().append_child_value("manufacturer","SCCN")
cap = info.desc().append_child("cap")
cap.append_child_value("name","EasyCap")
cap.append_child_value("size","54")
cap.append_child_value("labelscheme","10-20")
# create outlet for the stream
outlet = StreamOutlet(info)
# === the following could run on another computer ===
# resolve the stream and open an inlet
results = resolve_stream("name","MetaTester")
inlet = StreamInlet(results[0])
# get the full stream info (including custom meta-data) and dissect it
inf = inlet.info()
print "The stream's XML meta-data is: "
print inf.as_xml()
print "The manufacturer is: " + inf.desc().child_value("manufacturer")
print "The cap circumference is: " + inf.desc().child("cap").child_value("size")
print "The channel labels are as follows:"
ch = inf.desc().child("channels").child("channel")
for k in range(info.channel_count()):
print " " + ch.child_value("label")
ch = ch.next_sibling()
time.sleep(3)
