serializers: allow str | bytes | None

src/pipecat/serializers/twilio.py

@@ -0,0 +1,42 @@
+import base64
+import json
+
+from pipecat.frames.frames import AudioRawFrame, Frame
+from pipecat.serializers.base_serializer import FrameSerializer
+from pipecat.utils.audio import ulaw_8000_to_pcm_16000, pcm_16000_to_ulaw_8000
+
+
+class TwilioFrameSerializer(FrameSerializer):
+    SERIALIZABLE_TYPES = {
+        AudioRawFrame: "audio",
+    }
+
+    def __init__(self):
+        self.sid = None
+
+
+    def serialize(self, frame: AudioRawFrame) -> dict:
+        data = frame.audio
+
+        serialized_data = pcm_16000_to_ulaw_8000(data)
+        payload = base64.b64encode(serialized_data).decode('utf-8')
+        answer_dict = {"event": "media",
+                       "streamSid": self.sid,
+                       "media": {"payload": payload}}
+
+        return answer_dict
+
+    def deserialize(self, message: bytes) -> AudioRawFrame | None:
+        data = json.loads(message)
+        if not self.sid:
+            self.sid = data['streamSid'] if data.get("streamSid") else None
+
+        if data['event'] != 'media':
+            return None
+        else:
+            payload_base64 = data['media']['payload']
+            payload = base64.b64decode(payload_base64)
+
+            deserialized_data = ulaw_8000_to_pcm_16000(payload)
+            audio_frame = AudioRawFrame(audio=deserialized_data, num_channels=1, sample_rate=16000)
+            return audio_frame