BaseTransportOutput: allow pushing frames upstream

CHANGELOG.md

@@ -91,6 +91,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Fixed a `BaseOutputTransport` issue that was causing upstream frames to no be
+  pushed upstream.
+
 - Fixed multiple issue where user transcriptions where not being handled
   properly. It was possible for short utterances to not trigger VAD which would
   cause user transcriptions to be ignored. It was also possible for one or more

src/pipecat/transports/base_output.py

@@ -170,6 +170,8 @@ class BaseOutputTransport(FrameProcessor):
         # TODO(aleix): Images and audio should support presentation timestamps.
         elif frame.pts:
             await self._sink_clock_queue.put((frame.pts, frame.id, frame))
+        elif direction == FrameDirection.UPSTREAM:
+            await self.push_frame(frame, direction)
         else:
             await self._sink_queue.put(frame)