Additional LLM and TTS metrics (#343)

* added llm and tts usage metrics

* Metrics debug logging

* cleanup

examples/foundational/06-listen-and-respond.py

@@ -9,14 +9,15 @@ import aiohttp
 import os
 import sys
 
-from pipecat.frames.frames import LLMMessagesFrame
+from pipecat.frames.frames import Frame, LLMMessagesFrame, MetricsFrame
 from pipecat.pipeline.pipeline import Pipeline
 from pipecat.pipeline.runner import PipelineRunner
-from pipecat.pipeline.task import PipelineTask
+from pipecat.pipeline.task import PipelineParams, PipelineTask
 from pipecat.processors.aggregators.llm_response import (
     LLMAssistantResponseAggregator,
     LLMUserResponseAggregator,
 )
+from pipecat.processors.frame_processor import FrameDirection, FrameProcessor
 from pipecat.processors.logger import FrameLogger
 from pipecat.services.elevenlabs import ElevenLabsTTSService
 from pipecat.services.openai import OpenAILLMService
@@ -34,6 +35,14 @@ logger.remove(0)
 logger.add(sys.stderr, level="DEBUG")
 
 
+class MetricsLogger(FrameProcessor):
+    async def process_frame(self, frame: Frame, direction: FrameDirection):
+        if isinstance(frame, MetricsFrame):
+            print(
+                f"!!! MetricsFrame: {frame}, ttfb: {frame.ttfb}, processing: {frame.processing}, tokens: {frame.tokens}, characters: {frame.characters}")
+        await self.push_frame(frame, direction)
+
+
 async def main():
     async with aiohttp.ClientSession() as session:
         (room_url, token) = await configure(session)
@@ -58,11 +67,10 @@ async def main():
 
         llm = OpenAILLMService(
             api_key=os.getenv("OPENAI_API_KEY"),
-            model="gpt-4o")
+            model="gpt-4o"
+        )
 
-        fl = FrameLogger("!!! after LLM", "red")
-        fltts = FrameLogger("@@@ out of tts", "green")
-        flend = FrameLogger("### out of the end", "magenta")
+        ml = MetricsLogger()
 
         messages = [
             {
@@ -77,15 +85,18 @@ async def main():
             transport.input(),
             tma_in,
             llm,
-            fl,
             tts,
-            fltts,
+            ml,
             transport.output(),
             tma_out,
-            flend
         ])
 
         task = PipelineTask(pipeline)
+        task = PipelineTask(pipeline, PipelineParams(
+            allow_interruptions=True,
+            enable_metrics=True,
+            report_only_initial_ttfb=False,
+        ))
 
         @transport.event_handler("on_first_participant_joined")
         async def on_first_participant_joined(transport, participant):