Use webrcvad to detect silence in pipelines (#90610)

* Add webrtcvad requirement

* Use webrcvad for voice command segmenting

* Add vad test

tests/components/voice_assistant/test_vad.py

@@ -0,0 +1,38 @@
+"""Tests for webrtcvad voice command segmenter."""
+from unittest.mock import patch
+
+from homeassistant.components.voice_assistant.vad import VoiceCommandSegmenter
+
+_ONE_SECOND = 16000 * 2  # 16Khz 16-bit
+
+
+def test_silence() -> None:
+    """Test that 3 seconds of silence does not trigger a voice command."""
+    segmenter = VoiceCommandSegmenter()
+
+    # True return value indicates voice command has not finished
+    assert segmenter.process(bytes(_ONE_SECOND * 3))
+
+
+def test_speech() -> None:
+    """Test that silence + speech + silence triggers a voice command."""
+
+    def is_speech(self, chunk, sample_rate):
+        """Anything non-zero is speech."""
+        return sum(chunk) > 0
+
+    with patch(
+        "webrtcvad.Vad.is_speech",
+        new=is_speech,
+    ):
+        segmenter = VoiceCommandSegmenter()
+
+        # silence
+        assert segmenter.process(bytes(_ONE_SECOND))
+
+        # "speech"
+        assert segmenter.process(bytes([255] * _ONE_SECOND))
+
+        # silence
+        # False return value indicates voice command is finished
+        assert not segmenter.process(bytes(_ONE_SECOND))

tests/components/voice_assistant/test_websocket.py

@@ -75,7 +75,7 @@ class MockSTT:
         hass: HomeAssistant,
         config: ConfigType,
         discovery_info: DiscoveryInfoType | None = None,
-    ) -> tts.Provider:
+    ) -> stt.Provider:
         """Set up a mock speech component."""
         return MockSttProvider(hass, _TRANSCRIPT)