Merge pull request #4430 from pipecat-ai/filipi/flux_audio

Implementing dynamic watchdog timeout for Deepgram Flux STT

changelog/4430.added.md

@@ -0,0 +1 @@
+- Added `watchdog_min_timeout` parameter to `DeepgramFluxSTT` and `DeepgramFluxSageMakerSTT` (default `0.5` seconds) to control the minimum silence duration before the watchdog sends a silence packet to prevent dangling turns. The actual threshold is `max(chunk_duration * 2, watchdog_min_timeout)`, so it also adapts automatically to the audio chunk size in use.

changelog/4430.changed.md

@@ -0,0 +1 @@
+- `DeepgramFluxSTT` watchdog silence threshold is now dynamic: `max(chunk_duration * 2, watchdog_min_timeout)` instead of a fixed 500 ms. This prevents false silence injections when large audio chunks are sent at lower frequency.

src/pipecat/services/deepgram/flux/base.py

@@ -162,6 +162,7 @@ class DeepgramFluxSTTBase(STTService):
         mip_opt_out: bool | None = None,
         tag: list | None = None,
         should_interrupt: bool = True,
+        watchdog_min_timeout: float = 0.5,
         settings: Settings,
         **kwargs,
     ):
@@ -173,6 +174,9 @@ class DeepgramFluxSTTBase(STTService):
             tag: Tags to label requests for identification during usage reporting.
             should_interrupt: Whether to interrupt the bot when Flux detects that
                 the user is speaking.
+            watchdog_min_timeout: minimum idle timeout before sending silence to
+                prevent dangling turns. The actual threshold is
+                ``max(chunk_duration * 2, watchdog_min_timeout)``. Defaults to 0.5.
             settings: Fully resolved settings instance (built by concrete subclass).
             **kwargs: Additional arguments passed to the parent STTService (e.g.
                 ``sample_rate``, ``reconnect_on_error``).
@@ -183,6 +187,7 @@ class DeepgramFluxSTTBase(STTService):
         self._mip_opt_out = mip_opt_out
         self._tag = tag or []
         self._should_interrupt = should_interrupt
+        self._watchdog_min_timeout = watchdog_min_timeout
 
         # Connection readiness: Flux sends a "Connected" message when ready
         self._connection_established_event = asyncio.Event()
@@ -191,6 +196,7 @@ class DeepgramFluxSTTBase(STTService):
         self._last_stt_time: float | None = None
         self._watchdog_task: asyncio.Task | None = None
         self._user_is_speaking = False
+        self._last_audio_chunk_duration: float = 0.0
 
         # Flux event handlers
         self._register_event_handler("on_start_of_turn")
@@ -291,9 +297,17 @@ class DeepgramFluxSTTBase(STTService):
         """
         while self._transport_is_active():
             now = time.monotonic()
-            # More than 500 ms without sending new audio to Flux
+            # Send silence if we go more than 500 ms or twice the chunk size
-            if self._user_is_speaking and self._last_stt_time and now - self._last_stt_time > 0.5:
+            # without sending new audio to Flux.
-                logger.warning("Sending silence to Flux to prevent dangling task")
+            threshold = max(self._last_audio_chunk_duration * 2, self._watchdog_min_timeout)
+            if (
+                self._user_is_speaking
+                and self._last_stt_time
+                and now - self._last_stt_time > threshold
+            ):
+                logger.warning(
+                    f"No audio received for {threshold * 1000:.0f} ms. Sending silence to Flux to prevent a dangling task"
+                )
                 try:
                     await self._send_silence()
                 except Exception as e:

src/pipecat/services/deepgram/flux/sagemaker/stt.py

@@ -89,6 +89,7 @@ class DeepgramFluxSageMakerSTTService(DeepgramFluxSTTBase):
         mip_opt_out: bool | None = None,
         tag: list | None = None,
         should_interrupt: bool = True,
+        watchdog_min_timeout: float = 0.5,
         settings: Settings | None = None,
         **kwargs,
     ):
@@ -105,6 +106,8 @@ class DeepgramFluxSageMakerSTTService(DeepgramFluxSTTBase):
             tag: Tags to label requests for identification during usage reporting.
             should_interrupt: Whether to interrupt the bot when Flux detects that
                 the user is speaking. Defaults to True.
+            watchdog_min_timeout: Minimum silence duration in seconds before the watchdog
+                sends silence to prevent dangling turns. Defaults to 0.5.
             settings: Runtime-updatable settings.
             **kwargs: Additional arguments passed to the parent STTService.
         """
@@ -129,6 +132,7 @@ class DeepgramFluxSageMakerSTTService(DeepgramFluxSTTBase):
             mip_opt_out=mip_opt_out,
             tag=tag,
             should_interrupt=should_interrupt,
+            watchdog_min_timeout=watchdog_min_timeout,
             settings=default_settings,
             sample_rate=sample_rate,
             **kwargs,
@@ -245,6 +249,7 @@ class DeepgramFluxSageMakerSTTService(DeepgramFluxSTTBase):
         if self._client and self._client.is_active:
             try:
                 self._last_stt_time = time.monotonic()
+                self._last_audio_chunk_duration = len(audio) / (self.sample_rate * 2)
                 await self._client.send_audio_chunk(audio)
             except Exception as e:
                 yield ErrorFrame(error=f"Unknown error occurred: {e}")

src/pipecat/services/deepgram/flux/stt.py

@@ -115,6 +115,7 @@ class DeepgramFluxSTTService(DeepgramFluxSTTBase, WebsocketService):
         tag: list | None = None,
         params: InputParams | None = None,
         should_interrupt: bool = True,
+        watchdog_min_timeout: float = 0.5,
         settings: Settings | None = None,
         **kwargs,
     ):
@@ -140,6 +141,8 @@ class DeepgramFluxSTTService(DeepgramFluxSTTBase, WebsocketService):
                     Use ``settings=DeepgramFluxSTTService.Settings(...)`` instead.
 
             should_interrupt: Determine whether the bot should be interrupted when Flux detects that the user is speaking.
+            watchdog_min_timeout: Minimum silence duration in seconds before the watchdog
+                sends silence to prevent dangling turns. Defaults to 0.5.
             settings: Runtime-updatable settings. When provided alongside deprecated
                 parameters, ``settings`` values take precedence.
             **kwargs: Additional arguments passed to the parent classes.
@@ -224,6 +227,7 @@ class DeepgramFluxSTTService(DeepgramFluxSTTBase, WebsocketService):
             mip_opt_out=mip_opt_out,
             tag=tag,
             should_interrupt=should_interrupt,
+            watchdog_min_timeout=watchdog_min_timeout,
             settings=default_settings,
             sample_rate=sample_rate,
             **kwargs,
@@ -390,6 +394,7 @@ class DeepgramFluxSTTService(DeepgramFluxSTTBase, WebsocketService):
 
         try:
             self._last_stt_time = time.monotonic()
+            self._last_audio_chunk_duration = len(audio) / (self.sample_rate * 2)
             await self.send_with_retry(audio, self._report_error)
         except Exception as e:
             yield ErrorFrame(error=f"Unknown error occurred: {e}")