Update gradio-voice to use fastrtc (#2093)

Author: freddyaboulton

gemini/multimodal-live-api/gradio-voice/app.py

@@ -1,7 +1,8 @@
 import asyncio
 import pathlib
-from typing import AsyncGenerator, Literal
+from typing import AsyncGenerator, Literal, cast
 
+from fastrtc import AsyncStreamHandler, WebRTC, async_aggregate_bytes_to_16bit
 from google import genai
 from google.genai.types import (
     Content,
@@ -12,7 +13,6 @@
     VoiceConfig,
 )
 import gradio as gr
-from gradio_webrtc import AsyncStreamHandler, WebRTC, async_aggregate_bytes_to_16bit
 import numpy as np
 
 current_dir = pathlib.Path(__file__).parent
@@ -41,7 +41,7 @@ def __init__(
     def copy(self) -> "GeminiHandler":
         """Required implementation of the copy method for AsyncStreamHandler"""
         return GeminiHandler(
-            expected_layout=self.expected_layout,
+            expected_layout=cast(Literal["mono"], self.expected_layout),
             output_sample_rate=self.output_sample_rate,
             output_frame_size=self.output_frame_size,
         )
@@ -71,7 +71,13 @@ async def connect(
                     )
                 )
             ),
-            system_instruction=Content(parts=[Part.from_text(text=system_instruction)]),
+            system_instruction=Content(
+                parts=[
+                    Part.from_text(
+                        text=system_instruction or "You are a helpful assistant."
+                    )
+                ]
+            ),
         )
         async with client.aio.live.connect(
             model="gemini-2.0-flash-live-preview-04-09", config=config
@@ -153,7 +159,7 @@ def shutdown(self) -> None:
             mode="send-receive",
             # See for changes needed to deploy behind a firewall
             # https://fastrtc.org/deployment/
-            rtc_configuration=None,
+            rtc_configuration={},
         )
 
         webrtc.stream(

gemini/multimodal-live-api/gradio-voice/requirements.txt

@@ -1,4 +1,4 @@
 gradio>=5.12.0,<6.0
-gradio_webrtc
+fastrtc
 librosa
 google-genai==1.10.0