Not creating InputAudioRawFrame in case we don't have bytes. Fixed for Pilvo, Exotel and Telnyx.

src/pipecat/serializers/exotel.py

@@ -144,6 +144,9 @@ class ExotelFrameSerializer(FrameSerializer):
                 self._exotel_sample_rate,
                 self._sample_rate,
             )
+            if deserialized_data is None or len(deserialized_data) == 0:
+                # Ignoring in case we don't have audio
+                return None
 
             # Input: Exotel takes PCM data, so just resample to match sample_rate
             audio_frame = InputAudioRawFrame(

src/pipecat/serializers/plivo.py

@@ -227,6 +227,10 @@ class PlivoFrameSerializer(FrameSerializer):
             deserialized_data = await ulaw_to_pcm(
                 payload, self._plivo_sample_rate, self._sample_rate, self._input_resampler
             )
+            if deserialized_data is None or len(deserialized_data) == 0:
+                # Ignoring in case we don't have audio
+                return None
+
             audio_frame = InputAudioRawFrame(
                 audio=deserialized_data, num_channels=1, sample_rate=self._sample_rate
             )

src/pipecat/serializers/telnyx.py

@@ -262,6 +262,10 @@ class TelnyxFrameSerializer(FrameSerializer):
             else:
                 raise ValueError(f"Unsupported encoding: {self._params.outbound_encoding}")
 
+            if deserialized_data is None or len(deserialized_data) == 0:
+                # Ignoring in case we don't have audio
+                return None
+
             audio_frame = InputAudioRawFrame(
                 audio=deserialized_data, num_channels=1, sample_rate=self._sample_rate
             )