introduce input/output audio and image frames

We now distinguish between input and output audio and image frames. We introduce
`InputAudioRawFrame`, `OutputAudioRawFrame`, `InputImageRawFrame` and
`OutputImageRawFrame` (and other subclasses of those). The input frames usually
come from an input transport and are meant to be processed inside the pipeline
to generate new frames. However, the input frames will not be sent through an
output transport. The output frames can also be processed by any frame processor
in the pipeline and they are allowed to be sent by the output transport.

examples/websocket-server/bot.py

@@ -4,7 +4,6 @@
 # SPDX-License-Identifier: BSD 2-Clause License
 #
 
-import aiohttp
 import asyncio
 import os
 import sys
@@ -33,60 +32,59 @@ logger.add(sys.stderr, level="DEBUG")
 
 
 async def main():
-    async with aiohttp.ClientSession() as session:
-        transport = WebsocketServerTransport(
-            params=WebsocketServerParams(
-                audio_out_enabled=True,
-                add_wav_header=True,
-                vad_enabled=True,
-                vad_analyzer=SileroVADAnalyzer(),
-                vad_audio_passthrough=True
-            )
+    transport = WebsocketServerTransport(
+        params=WebsocketServerParams(
+            audio_out_enabled=True,
+            add_wav_header=True,
+            vad_enabled=True,
+            vad_analyzer=SileroVADAnalyzer(),
+            vad_audio_passthrough=True
         )
+    )
 
-        llm = OpenAILLMService(
-            api_key=os.getenv("OPENAI_API_KEY"),
-            model="gpt-4o")
+    llm = OpenAILLMService(
+        api_key=os.getenv("OPENAI_API_KEY"),
+        model="gpt-4o")
 
-        stt = DeepgramSTTService(api_key=os.getenv("DEEPGRAM_API_KEY"))
+    stt = DeepgramSTTService(api_key=os.getenv("DEEPGRAM_API_KEY"))
 
-        tts = CartesiaTTSService(
-            api_key=os.getenv("CARTESIA_API_KEY"),
-            voice_id="79a125e8-cd45-4c13-8a67-188112f4dd22",  # British Lady
-        )
+    tts = CartesiaTTSService(
+        api_key=os.getenv("CARTESIA_API_KEY"),
+        voice_id="79a125e8-cd45-4c13-8a67-188112f4dd22",  # British Lady
+    )
 
-        messages = [
-            {
-                "role": "system",
-                "content": "You are a helpful LLM in a WebRTC call. Your goal is to demonstrate your capabilities in a succinct way. Your output will be converted to audio so don't include special characters in your answers. Respond to what the user said in a creative and helpful way.",
-            },
-        ]
+    messages = [
+        {
+            "role": "system",
+            "content": "You are a helpful LLM in a WebRTC call. Your goal is to demonstrate your capabilities in a succinct way. Your output will be converted to audio so don't include special characters in your answers. Respond to what the user said in a creative and helpful way.",
+        },
+    ]
 
-        tma_in = LLMUserResponseAggregator(messages)
-        tma_out = LLMAssistantResponseAggregator(messages)
+    tma_in = LLMUserResponseAggregator(messages)
+    tma_out = LLMAssistantResponseAggregator(messages)
 
-        pipeline = Pipeline([
-            transport.input(),   # Websocket input from client
-            stt,                 # Speech-To-Text
-            tma_in,              # User responses
-            llm,                 # LLM
-            tts,                 # Text-To-Speech
-            transport.output(),  # Websocket output to client
-            tma_out              # LLM responses
-        ])
+    pipeline = Pipeline([
+        transport.input(),   # Websocket input from client
+        stt,                 # Speech-To-Text
+        tma_in,              # User responses
+        llm,                 # LLM
+        tts,                 # Text-To-Speech
+        transport.output(),  # Websocket output to client
+        tma_out              # LLM responses
+    ])
 
-        task = PipelineTask(pipeline)
+    task = PipelineTask(pipeline)
 
-        @transport.event_handler("on_client_connected")
-        async def on_client_connected(transport, client):
-            # Kick off the conversation.
-            messages.append(
-                {"role": "system", "content": "Please introduce yourself to the user."})
-            await task.queue_frames([LLMMessagesFrame(messages)])
+    @transport.event_handler("on_client_connected")
+    async def on_client_connected(transport, client):
+        # Kick off the conversation.
+        messages.append(
+            {"role": "system", "content": "Please introduce yourself to the user."})
+        await task.queue_frames([LLMMessagesFrame(messages)])
 
-        runner = PipelineRunner()
+    runner = PipelineRunner()
 
-        await runner.run(task)
+    await runner.run(task)
 
 if __name__ == "__main__":
     asyncio.run(main())