[唤醒应答加速]：完成ACK音频预热缓存，包含唤醒后复用播放和回归测试

src/owner_voice_pet/assistant_pipeline.py

@@ -122,6 +122,8 @@ class TurnController:
         self.sentence_buffer = sentence_buffer or SentenceBuffer()
         self._states: list[PipelineState] = []
         self._pending_capture_frames: list[AudioFrame] = []
+        self._cached_ack_text: str | None = None
+        self._cached_ack_segment: AudioSegment | None = None
 
     def run_turn(self, turn_id: int) -> TurnResult:
         self._states = []
@@ -139,6 +141,15 @@ class TurnController:
         except ProviderError as exc:
             return self._recover(exc, turn_id)
 
+    def prepare_ack_audio(self) -> None:
+        text = self.config.wake_ack_text.strip()
+        if not text:
+            self._cached_ack_text = None
+            self._cached_ack_segment = None
+            return
+        self._cached_ack_text = text
+        self._cached_ack_segment = self.ack_tts.synthesize(text)
+
     def _wait_for_wake_and_user_text(self, turn_id: int) -> str | ProviderError:
         wake_error = self._wait_for_local_wake()
         if wake_error is not None:
@@ -300,7 +311,7 @@ class TurnController:
             return None
         try:
             self._event(ACK_STARTED, PipelineState.SPEAKING, f"应答中：{text}", turn_id=turn_id)
-            segment = self.ack_tts.synthesize(text)
+            segment = self._ack_segment(text)
             playback = self.transport.play_pcm(segment)
             if playback.error:
                 return playback.error
@@ -309,6 +320,12 @@ class TurnController:
         except ProviderError as exc:
             return exc
 
+    def _ack_segment(self, text: str) -> AudioSegment:
+        if self._cached_ack_text != text or self._cached_ack_segment is None:
+            self._cached_ack_text = text
+            self._cached_ack_segment = self.ack_tts.synthesize(text)
+        return self._cached_ack_segment
+
     def _reply_to_user(self, user_text: str, turn_id: int) -> TurnResult:
         completed_turns = 0
         current_user_text = user_text
@@ -664,6 +681,7 @@ class VoiceAssistantPipeline:
         self.tts.load()
         if self.ack_tts is not self.tts:
             self.ack_tts.load()
+        self.controller.prepare_ack_audio()
 
     def run(self, *, once: bool = False, max_turns: int | None = None) -> RuntimeSummary:
         completed = 0

src/owner_voice_pet/runtime.py

@@ -115,6 +115,8 @@ class LiveVoiceRuntime:
         self.event_bus.subscribe(self._report_event)
         self.sentence_buffer = sentence_buffer or SentenceBuffer()
         self._states: list[PipelineState] = []
+        self._cached_ack_text: str | None = None
+        self._cached_ack_segment: AudioSegment | None = None
 
     def load(self) -> None:
         self.wakeword.load()
@@ -123,6 +125,16 @@ class LiveVoiceRuntime:
         self.tts.load()
         if self.ack_tts is not self.tts:
             self.ack_tts.load()
+        self.prepare_ack_audio()
+
+    def prepare_ack_audio(self) -> None:
+        text = self.config.wake_ack_text.strip()
+        if not text:
+            self._cached_ack_text = None
+            self._cached_ack_segment = None
+            return
+        self._cached_ack_text = text
+        self._cached_ack_segment = self.ack_tts.synthesize(text)
 
     def run(self, *, once: bool = False, max_turns: int | None = None) -> RuntimeSummary:
         completed = 0
@@ -243,7 +255,7 @@ class LiveVoiceRuntime:
             return None
         try:
             self._event(ACK_STARTED, PipelineState.SPEAKING, f"应答中：{text}", turn_id=turn_id)
-            segment = self.ack_tts.synthesize(text)
+            segment = self._ack_segment(text)
             playback = self.transport.play_pcm(segment)
             if playback.error:
                 return playback.error
@@ -252,6 +264,12 @@ class LiveVoiceRuntime:
         except ProviderError as exc:
             return exc
 
+    def _ack_segment(self, text: str) -> AudioSegment:
+        if self._cached_ack_text != text or self._cached_ack_segment is None:
+            self._cached_ack_text = text
+            self._cached_ack_segment = self.ack_tts.synthesize(text)
+        return self._cached_ack_segment
+
     def _drain_input_after_playback(self) -> None:
         self.transport.flush_input()
         if self.config.post_playback_drain_ms <= 0:

tests/test_live_runtime.py

@@ -113,6 +113,19 @@ class QueueLlmProvider:
         yield ReplyDelta("", finish_reason="stop")
 
 
+class CountingTtsProvider:
+    def __init__(self) -> None:
+        self.delegate = SineTtsProvider()
+        self.synthesized_texts: list[str] = []
+
+    def load(self) -> None:
+        self.delegate.load()
+
+    def synthesize(self, text: str) -> AudioSegment:
+        self.synthesized_texts.append(text)
+        return self.delegate.synthesize(text)
+
+
 class RecordingReporter:
     def __init__(self) -> None:
         self.statuses: list[str] = []
@@ -282,6 +295,37 @@ class LiveRuntimeTests(unittest.TestCase):
         positions = [event_types.index(item) for item in expected_order]
         self.assertEqual(positions, sorted(positions))
 
+    def test_wake_ack_audio_is_prepared_once_and_reused(self) -> None:
+        frames = []
+        for idx, _text in enumerate(["第一问", "第二问"]):
+            base_id = idx * 5
+            base_ms = idx * 120
+            frames.append(wake_frame(base_id, base_ms))
+            frames.extend(segment_frames(base_id + 1, base_ms + 20))
+        transport = MemoryAudioTransport(frames, flush_clears_input=False)
+        ack_tts = CountingTtsProvider()
+        runtime = VoiceAssistantPipeline(
+            config=AppConfig(llm_api_key="secret", speech_provider="cloud", wake_ack_text="我在"),
+            transport=transport,
+            wakeword=KeywordWakeWordProvider(),
+            vad_recorder=VadRecorder(EnergyVadProvider(), min_duration_ms=40, end_silence_ms=40),
+            stt=QueueSttProvider(["第一问", "第二问"]),
+            realtime_stt=None,
+            llm=MockLlmProvider(["这是答复。"]),
+            tts=SineTtsProvider(),
+            ack_tts=ack_tts,
+            context=ConversationContext(),
+            reporter=RecordingReporter(),
+            event_bus=PipelineEventBus(),
+        )
+
+        summary = runtime.run(max_turns=2)
+
+        self.assertEqual(summary.completed_turns, 2)
+        self.assertEqual(ack_tts.synthesized_texts, ["我在"])
+        self.assertEqual(transport.played_segments[0].metadata["text"], "我在")
+        self.assertEqual(transport.played_segments[2].metadata["text"], "我在")
+
     def test_zero_post_playback_drain_flushes_without_dropping_prefilled_question(self) -> None:
         runtime, stt, _, transport, reporter = make_runtime(["第一问"])
         self.assertEqual(runtime.config.post_playback_drain_ms, 0)