Add DTMF input event support to Daily transport

Handle Daily's on_dtmf_event callback, convert it to an
InputDTMFFrame pushed into the input transport. Also add __str__
methods to InputDTMFFrame and OutputDTMFFrame for better logging.

src/pipecat/frames/frames.py

@@ -1001,7 +1001,8 @@ class OutputDTMFFrame(DTMFFrame, DataFrame):
     specify where the DTMF keypress should be sent.
     """
 
-    pass
+    def __str__(self):
+        return f"{self.name}(tone: {self.button})"
 
 
 #
@@ -1658,7 +1659,8 @@ class AssistantImageRawFrame(OutputImageRawFrame):
 class InputDTMFFrame(DTMFFrame, SystemFrame):
     """DTMF keypress input frame from transport."""
 
-    pass
+    def __str__(self):
+        return f"{self.name}(tone: {self.button.value})"
 
 
 @dataclass

src/pipecat/transports/daily/transport.py

@@ -22,6 +22,7 @@ import aiohttp
 from loguru import logger
 from pydantic import BaseModel
 
+from pipecat.audio.dtmf.types import KeypadEntry
 from pipecat.audio.vad.vad_analyzer import VADAnalyzer, VADParams
 from pipecat.frames.frames import (
     BotConnectedFrame,
@@ -31,6 +32,7 @@ from pipecat.frames.frames import (
     EndFrame,
     Frame,
     InputAudioRawFrame,
+    InputDTMFFrame,
     InputTransportMessageFrame,
     InterimTranscriptionFrame,
     OutputAudioRawFrame,
@@ -394,6 +396,7 @@ class DailyCallbacks(BaseModel):
         on_dialout_stopped: Called when dial-out is stopped.
         on_dialout_error: Called when dial-out encounters an error.
         on_dialout_warning: Called when dial-out has a warning.
+        on_dtmf_event: Called when a DTMF tone happens.
         on_participant_joined: Called when a participant joins.
         on_participant_left: Called when a participant leaves.
         on_participant_updated: Called when participant info is updated.
@@ -424,6 +427,7 @@ class DailyCallbacks(BaseModel):
     on_dialout_stopped: Callable[[Any], Awaitable[None]]
     on_dialout_error: Callable[[Any], Awaitable[None]]
     on_dialout_warning: Callable[[Any], Awaitable[None]]
+    on_dtmf_event: Callable[[Any], Awaitable[None]]
     on_participant_joined: Callable[[Mapping[str, Any]], Awaitable[None]]
     on_participant_left: Callable[[Mapping[str, Any], str], Awaitable[None]]
     on_participant_updated: Callable[[Mapping[str, Any]], Awaitable[None]]
@@ -1560,6 +1564,14 @@ class DailyTransportClient(EventHandler):
         """
         self._call_event_callback(self._callbacks.on_dialout_warning, data)
 
+    def on_dtmf_event(self, data: Any):
+        """Handle incoming DTMF events.
+
+        Args:
+            data: DTMF data.
+        """
+        self._call_event_callback(self._callbacks.on_dtmf_event, data)
+
     def on_participant_joined(self, participant):
         """Handle participant joined events.
 
@@ -2313,6 +2325,7 @@ class DailyTransport(BaseTransport):
             on_dialout_stopped=self._on_dialout_stopped,
             on_dialout_error=self._on_dialout_error,
             on_dialout_warning=self._on_dialout_warning,
+            on_dtmf_event=self._on_dtmf_event,
             on_participant_joined=self._on_participant_joined,
             on_participant_left=self._on_participant_left,
             on_participant_updated=self._on_participant_updated,
@@ -2354,6 +2367,7 @@ class DailyTransport(BaseTransport):
         self._register_event_handler("on_dialout_stopped")
         self._register_event_handler("on_dialout_error")
         self._register_event_handler("on_dialout_warning")
+        self._register_event_handler("on_dtmf_event")
         self._register_event_handler("on_first_participant_joined")
         self._register_event_handler("on_participant_joined")
         self._register_event_handler("on_participant_left")
@@ -2864,6 +2878,15 @@ class DailyTransport(BaseTransport):
         logger.warning(f"{self} dial-out warning: {data}")
         await self._call_event_handler("on_dialout_warning", data)
 
+    async def _on_dtmf_event(self, data):
+        """Handle incoming DTMF events."""
+        logger.debug(f"{self} DTMF event: {data}")
+        await self._call_event_handler("on_dtmf_event", data)
+
+        if self._input:
+            frame = InputDTMFFrame(button=KeypadEntry(data["tone"]))
+            await self._input.push_frame(frame)
+
     async def _on_participant_joined(self, participant):
         """Handle participant joined events."""
         id = participant["id"]