Fix push operation with a player having chunk_size set to 1

doc/changes/latest.rst

@@ -21,3 +21,4 @@ Version 1.4
 
 - Fix handling of warnings through the logger (:pr:`243` by `Mathieu Scheltienne`_)
 - Fix handling of CLI arguments through :class:`~mne_lsl.player.PlayerLSL` entry-point (:pr:`246` by `Mathieu Scheltienne`_)
+- Fix push operation by a :class:`~mne_lsl.player.PlayerLSL` with a ``chunk_size`` set to 1 to use :meth:`mne_lsl.lsl.StreamOutlet.push_sample` instead of :meth:`mne_lsl.lsl.StreamOutlet.push_chunk` (:pr:`257` by `Mathieu Scheltienne`_)

mne_lsl/player/player_lsl.py

@@ -271,7 +271,10 @@ def _stream(self) -> None:
                 stop,
                 self._target_timestamp,
             )
-            self._outlet.push_chunk(data, timestamp=self._target_timestamp)
+            if self._chunk_size == 1:
+                self._outlet.push_sample(data[0, :], timestamp=self._target_timestamp)
+            else:
+                self._outlet.push_chunk(data, timestamp=self._target_timestamp)
             self._stream_annotations(start, stop, start_timestamp)
         except Exception as exc:
             logger.error("%s: Stopping due to exception: %s", self._name, exc)

mne_lsl/player/tests/test_player_lsl.py

@@ -1,3 +1,4 @@
+import os
 import time
 from datetime import datetime, timezone
 from pathlib import Path
@@ -411,3 +412,19 @@ def test_player_n_repeat_invalid(raw):
         Player(raw, n_repeat=-1)
     with pytest.raises(TypeError, match="must be an integer"):
         Player(raw, n_repeat="1")
+
+
+@pytest.mark.skipif(
+    os.getenv("GITHUB_ACTIONS", "") == "true", reason="Unreliable on CIs."
+)
+def test_player_push_sample(fname):
+    """Test pushing individual sample with chunk_size=1."""
+    name = "Player-test_player_push_sample"
+    streams = resolve_streams(timeout=0.1)
+    assert len(streams) == 0
+    with Player(fname, name=name, chunk_size=1):
+        streams = resolve_streams()
+        assert len(streams) == 1
+        assert streams[0].name == name
+    streams = resolve_streams(timeout=0.1)
+    assert len(streams) == 0