processors: add AsyncGeneratorProcessor

CHANGELOG.md

@@ -9,6 +9,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Added `AsyncGeneratorProcessor`. This processor can be used together with a
+  `FrameSerializer` as an async generator. It provides a `generator()` function
+  that returns an `AsyncGenerator` and that yields serialized frames.
+
 - Added `EndTaskFrame` and `CancelTaskFrame`. These are new frames that are
   meant to be pushed upstream to tell the pipeline task to stop nicely or
   immediately respectively.

src/pipecat/processors/async_generator.py

@@ -0,0 +1,42 @@
+#
+# Copyright (c) 2024, Daily
+#
+# SPDX-License-Identifier: BSD 2-Clause License
+#
+
+import asyncio
+
+from typing import Any, AsyncGenerator
+
+from pipecat.frames.frames import (
+    CancelFrame,
+    EndFrame,
+    Frame,
+)
+from pipecat.processors.frame_processor import FrameProcessor, FrameDirection
+from pipecat.serializers.base_serializer import FrameSerializer
+
+
+class AsyncGeneratorProcessor(FrameProcessor):
+    def __init__(self, *, serializer: FrameSerializer, **kwargs):
+        super().__init__(**kwargs)
+        self._serializer = serializer
+        self._data_queue = asyncio.Queue()
+
+    async def process_frame(self, frame: Frame, direction: FrameDirection):
+        await super().process_frame(frame, direction)
+
+        if isinstance(frame, (CancelFrame, EndFrame)):
+            await self._data_queue.put(None)
+        else:
+            data = self._serializer.serialize(frame)
+            if data:
+                await self._data_queue.put(data)
+
+    async def generator(self) -> AsyncGenerator[Any, None]:
+        running = True
+        while running:
+            data = await self._data_queue.get()
+            running = data is not None
+            if data:
+                yield data