update CHANGELOG and fix formatting

CHANGELOG.md

@@ -9,6 +9,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Added `TelnyxFrameSerializer` to support Telnyx calls. A full running example
+  has also been added to `examples/telnyx-chatbot`.
+
 - Allow pushing silence audio frames before `TTSStoppedFrame`. This might be
   useful for testing purposes, for example, passing bot audio to an STT service
   which usually needs additional audio data to detect the utterance stopped.

examples/telnyx-chatbot/bot.py

@@ -16,18 +16,15 @@ from pipecat.pipeline.pipeline import Pipeline
 from pipecat.pipeline.runner import PipelineRunner
 from pipecat.pipeline.task import PipelineParams, PipelineTask
 from pipecat.processors.aggregators.openai_llm_context import OpenAILLMContext
-
 from pipecat.serializers.telnyx import TelnyxFrameSerializer
-
-from pipecat.services.elevenlabs import ElevenLabsTTSService, Language
 from pipecat.services.deepgram import DeepgramSTTService
+from pipecat.services.elevenlabs import ElevenLabsTTSService, Language
 from pipecat.services.openai import OpenAILLMService
 from pipecat.transports.network.fastapi_websocket import (
     FastAPIWebsocketParams,
     FastAPIWebsocketTransport,
 )
 
-
 load_dotenv(override=True)
 
 logger.remove(0)

examples/telnyx-chatbot/server.py

@@ -1,3 +1,9 @@
+#
+# Copyright (c) 2025, Daily
+#
+# SPDX-License-Identifier: BSD 2-Clause License
+#
+
 import json
 
 import uvicorn
@@ -16,11 +22,13 @@ app.add_middleware(
     allow_headers=["*"],
 )
 
+
 @app.post("/")
 async def start_call():
     print("POST TeXML")
     return HTMLResponse(content=open("templates/streams.xml").read(), media_type="application/xml")
 
+
 @app.websocket("/ws")
 async def websocket_endpoint(websocket: WebSocket):
     await websocket.accept()
@@ -33,5 +41,6 @@ async def websocket_endpoint(websocket: WebSocket):
     print("WebSocket connection accepted")
     await run_bot(websocket, stream_id, outbound_encoding, "PCMU")
 
+
 if __name__ == "__main__":
     uvicorn.run(app, host="0.0.0.0", port=8765)

examples/twilio-chatbot/server.py

@@ -1,3 +1,9 @@
+#
+# Copyright (c) 2025, Daily
+#
+# SPDX-License-Identifier: BSD 2-Clause License
+#
+
 import json
 
 import uvicorn

src/pipecat/audio/utils.py

@@ -81,7 +81,7 @@ def ulaw_to_pcm(ulaw_bytes: bytes, in_sample_rate: int, out_sample_rate: int):
 
     # Resample
     out_pcm_bytes = resample_audio(in_pcm_bytes, in_sample_rate, out_sample_rate)
-    
+
     return out_pcm_bytes
 
 
@@ -95,13 +95,13 @@ def pcm_to_ulaw(pcm_bytes: bytes, in_sample_rate: int, out_sample_rate: int):
     return ulaw_bytes
 
 
-def alaw_to_pcm(alaw_bytes: bytes, in_sample_rate: int, out_sample_rate: int) -> bytes:     
+def alaw_to_pcm(alaw_bytes: bytes, in_sample_rate: int, out_sample_rate: int) -> bytes:
     # Convert a-law to PCM
     in_pcm_bytes = audioop.alaw2lin(alaw_bytes, 2)
 
     # Resample
     out_pcm_bytes = resample_audio(in_pcm_bytes, in_sample_rate, out_sample_rate)
-    
+
     return out_pcm_bytes
 
 

src/pipecat/serializers/telnyx.py

@@ -9,7 +9,7 @@ import json
 
 from pydantic import BaseModel
 
-from pipecat.audio.utils import pcm_to_ulaw, ulaw_to_pcm, pcm_to_alaw, alaw_to_pcm
+from pipecat.audio.utils import alaw_to_pcm, pcm_to_alaw, pcm_to_ulaw, ulaw_to_pcm
 from pipecat.frames.frames import (
     AudioRawFrame,
     Frame,
@@ -28,10 +28,16 @@ class TelnyxFrameSerializer(FrameSerializer):
         inbound_encoding: str = "PCMU"
         outbound_encoding: str = "PCMU"
 
-    def __init__(self, stream_id: str, outbound_encoding: str, inbound_encoding: str, params: InputParams = InputParams()):
+    def __init__(
+        self,
+        stream_id: str,
+        outbound_encoding: str,
+        inbound_encoding: str,
+        params: InputParams = InputParams(),
+    ):
         self._stream_id = stream_id
         params.outbound_encoding = outbound_encoding
-        params.inbound_encoding = inbound_encoding  
+        params.inbound_encoding = inbound_encoding
         self._params = params
 
     @property
@@ -41,18 +47,18 @@ class TelnyxFrameSerializer(FrameSerializer):
     def serialize(self, frame: Frame) -> str | bytes | None:
         if isinstance(frame, AudioRawFrame):
             data = frame.audio
-            
+
             if self._params.inbound_encoding == "PCMU":
                 serialized_data = pcm_to_ulaw(
                     data, frame.sample_rate, self._params.telnyx_sample_rate
-                    )
+                )
             elif self._params.inbound_encoding == "PCMA":
                 serialized_data = pcm_to_alaw(
                     data, frame.sample_rate, self._params.telnyx_sample_rate
-                    )
+                )
             else:
-                raise ValueError(f"Unsupported encoding: {self._params.encoding}")
-            
+                raise ValueError(f"Unsupported encoding: {self._params.inbound_encoding}")
+
             payload = base64.b64encode(serialized_data).decode("utf-8")
             answer = {
                 "event": "media",
@@ -67,7 +73,7 @@ class TelnyxFrameSerializer(FrameSerializer):
 
     def deserialize(self, data: str | bytes) -> Frame | None:
         message = json.loads(data)
-        
+
         if message["event"] == "media":
             payload_base64 = message["media"]["payload"]
             payload = base64.b64decode(payload_base64)
@@ -81,7 +87,7 @@ class TelnyxFrameSerializer(FrameSerializer):
                     payload, self._params.telnyx_sample_rate, self._params.sample_rate
                 )
             else:
-                raise ValueError(f"Unsupported encoding: {self._params.encoding}")
+                raise ValueError(f"Unsupported encoding: {self._params.outbound_encoding}")
 
             audio_frame = InputAudioRawFrame(
                 audio=deserialized_data, num_channels=1, sample_rate=self._params.sample_rate