Merge pull request #1889 from pipecat-ai/mb/add-dtmf-aggregator

Add DTMFAggregator

CHANGELOG.md

@@ -24,6 +24,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added `OutputDTMFUrgentFrame` to send a DTMF keypress quickly. The previous
   `OutputDTMFFrame` queues the keypress with the rest of data frames.
 
+- Added `DTMFAggregator`, which aggregates keypad presses into
+  `TranscriptionFrame`s. Aggregation occurs after a timeout, termination key
+  press, or user interruption. You can specify the prefix of the
+  `TranscriptionFrame`.
+
 - Added new functions `DailyTransport.start_transcription()` and
   `DailyTransport.stop_transcription()` to be able to start and stop Daily
   transcription dynamically (maybe with different settings).

src/pipecat/processors/aggregators/dtmf_aggregator.py

@@ -0,0 +1,143 @@
+#
+# Copyright (c) 2024–2025, Daily
+#
+# SPDX-License-Identifier: BSD 2-Clause License
+#
+
+import asyncio
+from typing import Optional
+
+from pipecat.frames.frames import (
+    BotInterruptionFrame,
+    CancelFrame,
+    EndFrame,
+    Frame,
+    InputDTMFFrame,
+    KeypadEntry,
+    StartFrame,
+    TranscriptionFrame,
+)
+from pipecat.processors.frame_processor import FrameDirection, FrameProcessor
+from pipecat.utils.time import time_now_iso8601
+
+
+class DTMFAggregator(FrameProcessor):
+    """Aggregates DTMF frames into meaningful sequences for LLM processing.
+
+    The aggregator accumulates digits from InputDTMFFrame instances and flushes
+    when:
+    - Timeout occurs (configurable idle period)
+    - Termination digit is received (default: '#')
+    - EndFrame or CancelFrame is received
+
+    Emits TranscriptionFrame for compatibility with existing LLM context aggregators.
+
+    Args:
+        timeout: Idle timeout in seconds before flushing
+        termination_digit: Digit that triggers immediate flush
+        prefix: Prefix added to DTMF sequence in transcription
+    """
+
+    def __init__(
+        self,
+        timeout: float = 2.0,
+        termination_digit: KeypadEntry = KeypadEntry.POUND,
+        prefix: str = "DTMF: ",
+        **kwargs,
+    ):
+        super().__init__(**kwargs)
+        self._aggregation = ""
+        self._idle_timeout = timeout
+        self._termination_digit = termination_digit
+        self._prefix = prefix
+
+        self._digit_event = asyncio.Event()
+        self._aggregation_task: Optional[asyncio.Task] = None
+
+    async def process_frame(self, frame: Frame, direction: FrameDirection) -> None:
+        await super().process_frame(frame, direction)
+
+        if isinstance(frame, StartFrame):
+            self._create_aggregation_task()
+            await self.push_frame(frame, direction)
+        elif isinstance(frame, (EndFrame, CancelFrame)):
+            if self._aggregation:
+                await self._flush_aggregation()
+            await self._stop_aggregation_task()
+            await self.push_frame(frame, direction)
+        elif isinstance(frame, InputDTMFFrame):
+            # Push the DTMF frame downstream first
+            await self.push_frame(frame, direction)
+            # Then handle it in order for the TranscriptionFrame to be emitted
+            # after the InputDTMFFrame
+            await self._handle_dtmf_frame(frame)
+        else:
+            await self.push_frame(frame, direction)
+
+    async def _handle_dtmf_frame(self, frame: InputDTMFFrame):
+        """Handle DTMF input frame."""
+        is_first_digit = not self._aggregation
+
+        digit_value = frame.button.value
+        self._aggregation += digit_value
+
+        # For first digit, schedule interruption in separate task
+        if is_first_digit:
+            asyncio.create_task(self._send_interruption_task())
+
+        # Check for immediate flush conditions
+        if frame.button == self._termination_digit:
+            await self._flush_aggregation()
+        else:
+            # Signal digit received for timeout handling
+            self._digit_event.set()
+
+    async def _send_interruption_task(self):
+        """Send interruption frame safely in a separate task."""
+        try:
+            # Send the interruption frame
+            await self.push_frame(BotInterruptionFrame(), FrameDirection.UPSTREAM)
+        except Exception as e:
+            # Log error but don't propagate
+            print(f"Error sending interruption: {e}")
+
+    def _create_aggregation_task(self) -> None:
+        """Creates the aggregation task if it hasn't been created yet."""
+        if not self._aggregation_task:
+            self._aggregation_task = self.create_task(self._aggregation_task_handler())
+
+    async def _stop_aggregation_task(self) -> None:
+        """Stops the aggregation task."""
+        if self._aggregation_task:
+            await self.cancel_task(self._aggregation_task)
+            self._aggregation_task = None
+
+    async def _aggregation_task_handler(self):
+        """Background task that handles timeout-based flushing."""
+        while True:
+            try:
+                await asyncio.wait_for(self._digit_event.wait(), timeout=self._idle_timeout)
+                self._digit_event.clear()
+            except asyncio.TimeoutError:
+                if self._aggregation:
+                    await self._flush_aggregation()
+
+    async def _flush_aggregation(self):
+        """Flush the current aggregation as a TranscriptionFrame."""
+        if not self._aggregation:
+            return
+
+        sequence = self._aggregation
+        transcription_text = f"{self._prefix}{sequence}"
+
+        transcription_frame = TranscriptionFrame(
+            text=transcription_text, user_id="", timestamp=time_now_iso8601()
+        )
+        await self.push_frame(transcription_frame)
+
+        self._aggregation = ""
+
+    async def cleanup(self) -> None:
+        """Clean up resources."""
+        await super().cleanup()
+        await self._stop_aggregation_task()

tests/test_dtmf_aggregator.py

@@ -0,0 +1,229 @@
+#
+# Copyright (c) 2024-2025 Daily
+#
+# SPDX-License-Identifier: BSD 2-Clause License
+#
+
+import unittest
+
+from pipecat.frames.frames import (
+    EndFrame,
+    InputDTMFFrame,
+    KeypadEntry,
+    TranscriptionFrame,
+)
+from pipecat.processors.aggregators.dtmf_aggregator import DTMFAggregator
+from pipecat.tests.utils import SleepFrame, run_test
+
+
+class TestDTMFAggregator(unittest.IsolatedAsyncioTestCase):
+    async def test_basic_aggregation_with_pound(self):
+        """Test basic DTMF aggregation ending with pound key."""
+        aggregator = DTMFAggregator()
+        frames_to_send = [
+            InputDTMFFrame(button=KeypadEntry.ONE),
+            InputDTMFFrame(button=KeypadEntry.TWO),
+            InputDTMFFrame(button=KeypadEntry.THREE),
+            InputDTMFFrame(button=KeypadEntry.POUND),
+        ]
+        expected_down_frames = [
+            InputDTMFFrame,
+            InputDTMFFrame,
+            InputDTMFFrame,
+            InputDTMFFrame,
+            TranscriptionFrame,
+        ]
+
+        received_down_frames, _ = await run_test(
+            aggregator,
+            frames_to_send=frames_to_send,
+            expected_down_frames=expected_down_frames,
+        )
+
+        # Find and verify the TranscriptionFrame
+        transcription_frames = [
+            f for f in received_down_frames if isinstance(f, TranscriptionFrame)
+        ]
+        self.assertEqual(len(transcription_frames), 1)
+        self.assertEqual(transcription_frames[0].text, "DTMF: 123#")
+
+    async def test_timeout_aggregation(self):
+        """Test DTMF aggregation with timeout flush."""
+        aggregator = DTMFAggregator(timeout=0.1)
+        frames_to_send = [
+            InputDTMFFrame(button=KeypadEntry.ONE),
+            InputDTMFFrame(button=KeypadEntry.TWO),
+            SleepFrame(sleep=0.2),  # This should trigger timeout
+            InputDTMFFrame(button=KeypadEntry.THREE),
+            SleepFrame(sleep=0.2),  # This should trigger another timeout
+        ]
+        expected_down_frames = [
+            InputDTMFFrame,
+            InputDTMFFrame,
+            TranscriptionFrame,  # First aggregation "12"
+            InputDTMFFrame,
+            TranscriptionFrame,  # Second aggregation "3"
+        ]
+
+        received_down_frames, _ = await run_test(
+            aggregator,
+            frames_to_send=frames_to_send,
+            expected_down_frames=expected_down_frames,
+        )
+
+        # Find the TranscriptionFrames
+        transcription_frames = [
+            f for f in received_down_frames if isinstance(f, TranscriptionFrame)
+        ]
+        self.assertEqual(len(transcription_frames), 2)
+        self.assertEqual(transcription_frames[0].text, "DTMF: 12")
+        self.assertEqual(transcription_frames[1].text, "DTMF: 3")
+
+    async def test_multiple_aggregations(self):
+        """Test multiple DTMF sequences with pound termination."""
+        aggregator = DTMFAggregator(timeout=0.2)
+        frames_to_send = [
+            InputDTMFFrame(button=KeypadEntry.ONE),
+            InputDTMFFrame(button=KeypadEntry.TWO),
+            InputDTMFFrame(button=KeypadEntry.POUND),  # First sequence
+            SleepFrame(sleep=0.1),
+            InputDTMFFrame(button=KeypadEntry.FOUR),
+            InputDTMFFrame(button=KeypadEntry.FIVE),
+            SleepFrame(sleep=0.3),  # Second sequence via timeout
+        ]
+        expected_down_frames = [
+            InputDTMFFrame,
+            InputDTMFFrame,
+            InputDTMFFrame,
+            TranscriptionFrame,  # "12#"
+            InputDTMFFrame,
+            InputDTMFFrame,
+            TranscriptionFrame,  # "45"
+        ]
+
+        received_down_frames, _ = await run_test(
+            aggregator,
+            frames_to_send=frames_to_send,
+            expected_down_frames=expected_down_frames,
+        )
+
+        transcription_frames = [
+            f for f in received_down_frames if isinstance(f, TranscriptionFrame)
+        ]
+        self.assertEqual(len(transcription_frames), 2)
+        self.assertEqual(transcription_frames[0].text, "DTMF: 12#")
+        self.assertEqual(transcription_frames[1].text, "DTMF: 45")
+
+    async def test_end_frame_flush(self):
+        """Test that EndFrame flushes pending aggregation."""
+        aggregator = DTMFAggregator(timeout=1.0)
+        frames_to_send = [
+            InputDTMFFrame(button=KeypadEntry.ONE),
+            InputDTMFFrame(button=KeypadEntry.TWO),
+            SleepFrame(sleep=0.1),  # Allow time for aggregation
+            EndFrame(),
+        ]
+        expected_down_frames = [
+            InputDTMFFrame,
+            InputDTMFFrame,
+            TranscriptionFrame,  # Should flush before EndFrame
+            EndFrame,
+        ]
+
+        received_down_frames, _ = await run_test(
+            aggregator,
+            frames_to_send=frames_to_send,
+            expected_down_frames=expected_down_frames,
+            send_end_frame=False,  # We're sending one in the test to test EndFrame logic
+        )
+
+        transcription_frames = [
+            f for f in received_down_frames if isinstance(f, TranscriptionFrame)
+        ]
+        self.assertEqual(len(transcription_frames), 1)
+        self.assertEqual(transcription_frames[0].text, "DTMF: 12")
+
+    async def test_custom_prefix(self):
+        """Test custom prefix configuration."""
+        aggregator = DTMFAggregator(prefix="Menu: ")
+        frames_to_send = [
+            InputDTMFFrame(button=KeypadEntry.ONE),
+            InputDTMFFrame(button=KeypadEntry.POUND),
+        ]
+        expected_down_frames = [
+            InputDTMFFrame,
+            InputDTMFFrame,
+            TranscriptionFrame,
+        ]
+
+        received_down_frames, _ = await run_test(
+            aggregator,
+            frames_to_send=frames_to_send,
+            expected_down_frames=expected_down_frames,
+        )
+
+        transcription_frames = [
+            f for f in received_down_frames if isinstance(f, TranscriptionFrame)
+        ]
+        self.assertEqual(len(transcription_frames), 1)
+        self.assertEqual(transcription_frames[0].text, "Menu: 1#")
+
+    async def test_custom_termination_digit(self):
+        """Test custom termination digit configuration."""
+        aggregator = DTMFAggregator(termination_digit=KeypadEntry.STAR)
+        frames_to_send = [
+            InputDTMFFrame(button=KeypadEntry.ONE),
+            InputDTMFFrame(button=KeypadEntry.TWO),
+            InputDTMFFrame(button=KeypadEntry.STAR),  # Custom terminator
+        ]
+        expected_down_frames = [
+            InputDTMFFrame,
+            InputDTMFFrame,
+            InputDTMFFrame,
+            TranscriptionFrame,
+        ]
+
+        received_down_frames, _ = await run_test(
+            aggregator,
+            frames_to_send=frames_to_send,
+            expected_down_frames=expected_down_frames,
+        )
+
+        transcription_frames = [
+            f for f in received_down_frames if isinstance(f, TranscriptionFrame)
+        ]
+        self.assertEqual(len(transcription_frames), 1)
+        self.assertEqual(transcription_frames[0].text, "DTMF: 12*")
+
+    async def test_all_keypad_entries(self):
+        """Test all possible keypad entries."""
+        aggregator = DTMFAggregator()
+        frames_to_send = [
+            InputDTMFFrame(button=KeypadEntry.ZERO),
+            InputDTMFFrame(button=KeypadEntry.ONE),
+            InputDTMFFrame(button=KeypadEntry.TWO),
+            InputDTMFFrame(button=KeypadEntry.THREE),
+            InputDTMFFrame(button=KeypadEntry.FOUR),
+            InputDTMFFrame(button=KeypadEntry.FIVE),
+            InputDTMFFrame(button=KeypadEntry.SIX),
+            InputDTMFFrame(button=KeypadEntry.SEVEN),
+            InputDTMFFrame(button=KeypadEntry.EIGHT),
+            InputDTMFFrame(button=KeypadEntry.NINE),
+            InputDTMFFrame(button=KeypadEntry.STAR),
+            InputDTMFFrame(button=KeypadEntry.POUND),
+        ]
+
+        # All the InputDTMFFrames plus one TranscriptionFrame
+        expected_down_frames = [InputDTMFFrame] * 12 + [TranscriptionFrame]
+
+        received_down_frames, _ = await run_test(
+            aggregator,
+            frames_to_send=frames_to_send,
+            expected_down_frames=expected_down_frames,
+        )
+
+        transcription_frames = [
+            f for f in received_down_frames if isinstance(f, TranscriptionFrame)
+        ]
+        self.assertEqual(len(transcription_frames), 1)
+        self.assertEqual(transcription_frames[0].text, "DTMF: 0123456789*#")