Realtime: fix interrupt logic (#1370)

I incorrectly created a playback tracker if none was specified. As a
result, interruption logic failed bc there was no audio tracking.

Author: rm-openai

examples/realtime/app/server.py

@@ -138,7 +138,6 @@ async def websocket_endpoint(websocket: WebSocket, session_id: str):
 
             if message["type"] == "audio":
                 # Convert int16 array to bytes
-                print("Received audio data")
                 int16_data = message["data"]
                 audio_bytes = struct.pack(f"{len(int16_data)}h", *int16_data)
                 await manager.send_audio(session_id, audio_bytes)

src/agents/realtime/openai_realtime.py

@@ -150,7 +150,7 @@ async def connect(self, options: RealtimeModelConfig) -> None:
 
         model_settings: RealtimeSessionModelSettings = options.get("initial_model_settings", {})
 
-        self._playback_tracker = options.get("playback_tracker", RealtimePlaybackTracker())
+        self._playback_tracker = options.get("playback_tracker", None)
 
         self.model = model_settings.get("model_name", self.model)
         api_key = await get_api_key(options.get("api_key"))
@@ -226,7 +226,7 @@ async def _listen_for_messages(self):
 
         except websockets.exceptions.ConnectionClosedOK:
             # Normal connection closure - no exception event needed
-            logger.info("WebSocket connection closed normally")
+            logger.debug("WebSocket connection closed normally")
         except websockets.exceptions.ConnectionClosed as e:
             await self._emit_event(
                 RealtimeModelExceptionEvent(
@@ -329,7 +329,7 @@ async def _send_interrupt(self, event: RealtimeModelSendInterrupt) -> None:
         current_item_content_index = playback_state.get("current_item_content_index")
         elapsed_ms = playback_state.get("elapsed_ms")
         if current_item_id is None or elapsed_ms is None:
-            logger.info(
+            logger.debug(
                 "Skipping interrupt. "
                 f"Item id: {current_item_id}, "
                 f"elapsed ms: {elapsed_ms}, "
@@ -351,6 +351,13 @@ async def _send_interrupt(self, event: RealtimeModelSendInterrupt) -> None:
                 int(elapsed_ms),
             )
             await self._send_raw_message(converted)
+        else:
+            logger.debug(
+                "Didn't interrupt bc elapsed ms is < 0. "
+                f"Item id: {current_item_id}, "
+                f"elapsed ms: {elapsed_ms}, "
+                f"content index: {current_item_content_index}"
+            )
 
         automatic_response_cancellation_enabled = (
             self._created_session