app.py

import asyncio
import base64
import os
import time
from io import BytesIO

import gradio as gr
import numpy as np
import websockets
from dotenv import load_dotenv
from fastrtc import (
    AsyncAudioVideoStreamHandler,
    Stream,
    WebRTC,
    get_cloudflare_turn_credentials_async,
    wait_for_item,
)
from google import genai
from gradio.utils import get_space
from PIL import Image

load_dotenv()


def encode_audio(data: np.ndarray) -> dict:
    """Encode Audio data to send to the server"""
    return {
        "mime_type": "audio/pcm",
        "data": base64.b64encode(data.tobytes()).decode("UTF-8"),
    }


def encode_image(data: np.ndarray) -> dict:
    with BytesIO() as output_bytes:
        pil_image = Image.fromarray(data)
        pil_image.save(output_bytes, "JPEG")
        bytes_data = output_bytes.getvalue()
    base64_str = str(base64.b64encode(bytes_data), "utf-8")
    return {"mime_type": "image/jpeg", "data": base64_str}


class GeminiHandler(AsyncAudioVideoStreamHandler):
    def __init__(
        self,
    ) -> None:
        super().__init__(
            "mono",
            output_sample_rate=24000,
            input_sample_rate=16000,
        )
        self.audio_queue = asyncio.Queue()
        self.video_queue = asyncio.Queue()
        self.session = None
        self.last_frame_time = 0
        self.quit = asyncio.Event()

    def copy(self) -> "GeminiHandler":
        return GeminiHandler()

    async def start_up(self):
        await self.wait_for_args()
        api_key = self.latest_args[3]
        client = genai.Client(
            api_key=api_key, http_options={"api_version": "v1alpha"}
        )
        config = {"response_modalities": ["AUDIO"], "system_instruction": "You are an art history teacher that will describe the artwork passed in as an image to the user. Describe the history and significance of the artwork."}
        async with client.aio.live.connect(
            model="gemini-2.0-flash-exp",
            config=config,  # type: ignore
        ) as session:
            self.session = session
            while not self.quit.is_set():
                turn = self.session.receive()
                try:
                    async for response in turn:
                        if data := response.data:
                            audio = np.frombuffer(data, dtype=np.int16).reshape(1, -1)
                        self.audio_queue.put_nowait(audio)
                except websockets.exceptions.ConnectionClosedOK:
                    print("connection closed")
                    break

    async def video_receive(self, frame: np.ndarray):
        self.video_queue.put_nowait(frame)

        if self.session:
            # send image every 1 second
            print(time.time() - self.last_frame_time)
            if time.time() - self.last_frame_time > 1:
                self.last_frame_time = time.time()
                await self.session.send(input=encode_image(frame))
                if self.latest_args[2] is not None:
                    await self.session.send(input=encode_image(self.latest_args[2]))

    async def video_emit(self):
        frame = await wait_for_item(self.video_queue, 0.01)
        if frame is not None:
            return frame
        else:
            return np.zeros((100, 100, 3), dtype=np.uint8)

    async def receive(self, frame: tuple[int, np.ndarray]) -> None:
        _, array = frame
        array = array.squeeze()
        audio_message = encode_audio(array)
        if self.session:
            await self.session.send(input=audio_message)

    async def emit(self):
        array = await wait_for_item(self.audio_queue, 0.01)
        if array is not None:
            return (self.output_sample_rate, array)
        return array

    async def shutdown(self) -> None:
        if self.session:
            self.quit.set()
            await self.session.close()
            self.quit.clear()


stream = Stream(
    handler=GeminiHandler(),
    modality="audio-video",
    mode="send-receive",
    rtc_configuration=get_cloudflare_turn_credentials_async if get_space() else None,
    time_limit=180 if get_space() else None,
    additional_inputs=[
        gr.Markdown(
            "## 🎨 Art History Teacher\n\n"
            "Provide an image of the artwork and Gemini will describe it to you."
            "To get a Gemini API key, please visit the [Gemini API Key](https://console.cloud.google.com/apis/api/generativelanguage.googleapis.com/credentials) page."
        ),
        gr.Image(label="Image", type="numpy", sources=["upload", "clipboard"]),
        gr.Textbox(label="Gemini API Key"),
    ],
    ui_args={
        "icon": "https://www.gstatic.com/lamda/images/gemini_favicon_f069958c85030456e93de685481c559f160ea06b.png",
        "pulse_color": "rgb(255, 255, 255)",
        "icon_button_color": "rgb(255, 255, 255)",
        "title": "Gemini Audio Video Chat",
    },
)

if __name__ == "__main__":
    stream.ui.launch()