CambTTSService: initialize client during StartFrame

Author: aconchillo

changelog/3511.fixed.md

@@ -0,0 +1 @@
+- Fixed a `CambTTSService` issue where client was being initialized in the constructor which wouldn't allow for proper Pipeline error handling.

src/pipecat/services/camb/tts.py

@@ -199,9 +199,10 @@ def __init__(
         """
         super().__init__(sample_rate=sample_rate, **kwargs)
 
-        params = params or CambTTSService.InputParams()
+        self._api_key = api_key
+        self._timeout = timeout
 
-        self._client = AsyncCambAI(api_key=api_key, timeout=timeout)
+        params = params or CambTTSService.InputParams()
 
         # Warn if sample rate doesn't match model's supported rate
         if sample_rate and sample_rate != MODEL_SAMPLE_RATES.get(model):
@@ -222,6 +223,8 @@ def __init__(
         self.set_voice(str(voice_id))
         self._voice_id = voice_id
 
+        self._client = None
+
     def can_generate_metrics(self) -> bool:
         """Check if this service can generate processing metrics.
 
@@ -249,6 +252,8 @@ async def start(self, frame: StartFrame):
         """
         await super().start(frame)
 
+        self._client = AsyncCambAI(api_key=self._api_key, timeout=self._timeout)
+
         # Use model-specific sample rate if not explicitly specified
         if not self._init_sample_rate:
             self._sample_rate = MODEL_SAMPLE_RATES.get(self.model_name, 22050)
@@ -289,6 +294,8 @@ async def run_tts(self, text: str) -> AsyncGenerator[Frame, None]:
             await self.start_tts_usage_metrics(text)
             yield TTSStartedFrame()
 
+            assert self._client is not None, "Camb.ai TTS service not initialized"
+
             # Buffer for aligning chunks to 2-byte boundaries (16-bit PCM)
             audio_buffer = b""