soundd: fix audio glitch in get_sound_data when frames < sound length

selfdrive/ui/soundd.py

@@ -106,6 +106,8 @@ def get_sound_data(self, frames): # get "frames" worth of data from the current
         ret[written_frames:written_frames+frames_to_write] = sound_data[current_sound_frame:current_sound_frame+frames_to_write]
         written_frames += frames_to_write
         self.current_sound_frame += frames_to_write
+        current_sound_frame = self.current_sound_frame % len(sound_data)
+        loops = self.current_sound_frame // len(sound_data)
 
     return ret * self.current_volume
 

selfdrive/ui/tests/test_soundd.py

@@ -1,7 +1,9 @@
+import numpy as np
+
 from cereal import car
 from cereal import messaging
 from cereal.messaging import SubMaster, PubMaster
-from openpilot.selfdrive.ui.soundd import SELFDRIVE_STATE_TIMEOUT, check_selfdrive_timeout_alert
+from openpilot.selfdrive.ui.soundd import SELFDRIVE_STATE_TIMEOUT, Soundd, check_selfdrive_timeout_alert
 
 import time
 
@@ -33,3 +35,97 @@ def test_check_selfdrive_timeout_alert(self):
 
   # TODO: add test with micd for checking that soundd actually outputs sounds
 
+
+class TestGetSoundData:
+  """Tests for get_sound_data boundary conditions (issue #36285)."""
+
+  def _make_soundd_with_test_sound(self, sound_data, alert=AudibleAlert.engage):
+    s = Soundd.__new__(Soundd)
+    s.current_alert = alert
+    s.current_volume = 1.0
+    s.current_sound_frame = 0
+    s.loaded_sounds = {alert: sound_data}
+    return s
+
+  def test_frames_equal_to_sound_length(self):
+    sound_data = np.arange(50, dtype=np.float32)
+    s = self._make_soundd_with_test_sound(sound_data)
+    result = s.get_sound_data(50)
+    np.testing.assert_array_equal(result, sound_data)
+
+  def test_frames_less_than_sound_length_single_callback(self):
+    sound_data = np.arange(70, dtype=np.float32)
+    s = self._make_soundd_with_test_sound(sound_data)
+    result = s.get_sound_data(50)
+    np.testing.assert_array_equal(result, sound_data[:50])
+    assert s.current_sound_frame == 50
+
+  def test_frames_less_than_sound_wraps_correctly(self):
+    """Regression test for #36285: second callback must wrap to start of sound, not repeat the tail."""
+    sound_data = np.arange(70, dtype=np.float32)
+    s = self._make_soundd_with_test_sound(sound_data, alert=AudibleAlert.promptRepeat)
+
+    # First callback: [0..49]
+    result1 = s.get_sound_data(50)
+    np.testing.assert_array_equal(result1, sound_data[:50])
+
+    # Second callback: should be [50..69, 0..29] (wrap around)
+    result2 = s.get_sound_data(50)
+    expected = np.concatenate([sound_data[50:70], sound_data[0:30]])
+    np.testing.assert_array_equal(result2, expected)
+
+  def test_single_play_stops_after_one_loop(self):
+    """Single-play sound should zero-fill after the sound ends."""
+    sound_data = np.arange(70, dtype=np.float32)
+    s = self._make_soundd_with_test_sound(sound_data)
+
+    result1 = s.get_sound_data(50)
+    np.testing.assert_array_equal(result1, sound_data[:50])
+
+    # Second callback: [50..69] then zeros (single play, no repeat)
+    result2 = s.get_sound_data(50)
+    expected = np.zeros(50, dtype=np.float32)
+    expected[:20] = sound_data[50:70]
+    np.testing.assert_array_equal(result2, expected)
+
+  def test_frames_larger_than_sound_wraps(self):
+    """When frames > sound length, the sound should loop within a single callback."""
+    sound_data = np.arange(30, dtype=np.float32)
+    s = self._make_soundd_with_test_sound(sound_data, alert=AudibleAlert.promptRepeat)
+
+    result = s.get_sound_data(50)
+    expected = np.concatenate([sound_data, sound_data[:20]])
+    np.testing.assert_array_equal(result, expected)
+
+  def test_multiple_consecutive_callbacks(self):
+    """Multiple callbacks should produce a continuous, correctly-wrapped stream."""
+    sound_data = np.arange(70, dtype=np.float32)
+    s = self._make_soundd_with_test_sound(sound_data, alert=AudibleAlert.promptRepeat)
+
+    all_samples = []
+    for _ in range(10):
+      result = s.get_sound_data(50)
+      all_samples.append(result)
+
+    # Verify the full stream is a continuous loop of sound_data
+    full_stream = np.concatenate(all_samples)  # 500 samples total
+    for i in range(len(full_stream)):
+      assert full_stream[i] == sound_data[i % len(sound_data)], \
+        f"Mismatch at index {i}: got {full_stream[i]}, expected {sound_data[i % len(sound_data)]}"
+
+  def test_no_alert_returns_silence(self):
+    s = Soundd.__new__(Soundd)
+    s.current_alert = AudibleAlert.none
+    s.current_volume = 1.0
+    s.current_sound_frame = 0
+    s.loaded_sounds = {}
+
+    result = s.get_sound_data(50)
+    np.testing.assert_array_equal(result, np.zeros(50, dtype=np.float32))
+
+  def test_volume_scaling(self):
+    sound_data = np.ones(50, dtype=np.float32)
+    s = self._make_soundd_with_test_sound(sound_data)
+    s.current_volume = 0.5
+    result = s.get_sound_data(50)
+    np.testing.assert_array_almost_equal(result, np.full(50, 0.5, dtype=np.float32))