108 lines
3.0 KiB
Python
108 lines
3.0 KiB
Python
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"""mjpeg.py
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This module implements a simple MJPEG server which handles HTTP
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requests from remote clients.
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"""
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import time
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import queue
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import threading
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import socket
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from http.server import BaseHTTPRequestHandler, HTTPServer
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from socketserver import ThreadingMixIn
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import numpy as np
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import cv2
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# globals
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_MJPEG_QUEUE = queue.Queue(maxsize=2)
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_SLEEP_INTERVAL = 0.1 # update JPG roughly every 0.1 second
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class MjpegHandler(BaseHTTPRequestHandler):
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"""A simple MJPEG handler which publishes images."""
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def _handle_mjpeg(self):
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global _MJPEG_QUEUE
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img = _MJPEG_QUEUE.get()
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self.send_response(200)
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self.send_header(
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'Content-type',
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'multipart/x-mixed-replace; boundary=--jpgboundary'
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)
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self.end_headers()
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while True:
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if not _MJPEG_QUEUE.empty():
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img = _MJPEG_QUEUE.get()
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ret, jpg = cv2.imencode('.jpg', img)
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assert jpg is not None
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self.wfile.write("--jpgboundary".encode("utf-8"))
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self.send_header('Content-type', 'image/jpeg')
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self.send_header('Content-length', str(jpg.size))
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self.end_headers()
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self.wfile.write(jpg.tostring())
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time.sleep(_SLEEP_INTERVAL)
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def _handle_error(self):
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self.send_response(404)
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self.send_header('Content-type', 'text/html')
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self.end_headers()
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self.wfile.write('<html><head></head><body>')
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self.wfile.write('<h1>{0!s} not found</h1>'.format(self.path))
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self.wfile.write('</body></html>')
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def do_GET(self):
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if self.path == '/mjpg' or self.path == '/':
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self._handle_mjpeg()
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else:
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#print('ERROR: ', self.path)
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self._handle_error()
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def handle(self):
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try:
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super().handle()
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except socket.error:
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# ignore BrokenPipeError, which is caused by the client
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# terminating the HTTP connection
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pass
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class ThreadedHTTPServer(ThreadingMixIn, HTTPServer):
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"""Handle HTTP requests in a separate thread."""
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# not used...
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def run_server(server):
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server.serve_forever() # this exits when server.shutdown() is called
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server.socket.shutdown(socket.SHUT_RDWR)
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server.socket.close()
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class MjpegServer(object):
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def __init__(self, init_img=None, ip='', port=8080):
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# initialize the queue with a dummy image
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global _MJPEG_QUEUE
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init_img = init_img if init_img else \
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np.ones((480, 640, 3), np.uint8) * 255 # all white
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_MJPEG_QUEUE.put(init_img)
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# create the HTTP server and run it from the child thread
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self.server = HTTPServer((ip, port), MjpegHandler)
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self.run_thread = threading.Thread(
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target=run_server, args=(self.server,))
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self.run_thread.start()
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def send_img(self, img):
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global _MJPEG_QUEUE
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try:
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_MJPEG_QUEUE.put(img, block=False)
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except queue.Full:
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pass
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def shutdown(self):
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self.server.shutdown()
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del self.server
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