Video stream from JPEG - Create an HTTP video stream from a file that periodically gets overwritten by another process

videostream.py

#!/usr/bin/env python3
import io
import os
from sys import argv
from time import sleep

from flask import Flask, Response, render_template
from PIL import Image

app = Flask(__name__)


def gen():
    im_path = argv[1]

    while True:
        sleep(1)

        if not os.path.isfile(im_path):
            continue

        bytestream = io.BytesIO()
        Image.open(im_path).save(bytestream, "JPEG")
        frame = bytestream.getvalue()
        yield (
            b"--frame\r\n"
            + b"Content-Type: image/jpeg\r\n\r\n"
            + frame
            + b"\r\n\r\n"
        )


@app.route("/video_feed")
def video_feed():
    return Response(
        gen(), mimetype="multipart/x-mixed-replace; boundary=frame"
    )


if __name__ == "__main__":
    app.run(host="0.0.0.0", debug=True)