import time import av import cv2 import numpy as np import requests from zoneinfo import ZoneInfo from datetime import datetime from threading import Lock, Thread, Event class FrameCapturer: def __init__(self, hls_url, cctv_id, interval=5, buffer_duration=15, buffer_size=600, time_zone="Asia/Seoul", endpoint="http://localhost:12345/cctv/infer"): ''' :param hls_url: hls address :param cctv_id: cctv_id number(whatever it is, this exists to distinguish from where. Further disscusion is needed with frontend developers.) :param interval: interval of sampling in seconds :param buffer_duration: video buffer, 15 seconds is default for ITS HLS video streaming :param time_zone: default Asia/Seoul :param endpoint: API endpoint ''' self.hls_url = hls_url self.interval = interval self.buffer_duration = buffer_duration self.buffer_size = buffer_size self.frame_buffer = [] self.current_frame = [] self.frame_buffer_lock = Lock() # for no memory sharing between receive_stream_packet and process_frames self.captured_frame_count = 0 self.last_capture_time = 0 self.start_time = time.time() self.stop_event = Event() self.input_stream = av.open(self.hls_url) self.video_stream = next(s for s in self.input_stream.streams if s.type == 'video') self.fps = self.video_stream.guessed_rate.numerator self.capture_interval = 1 / self.fps self.cctvid = cctv_id self.time_zone = ZoneInfo(time_zone) self.endpoint = endpoint def __call__(self, *args, **kwargs): return self.current_frame # ```receive_stream_packet``` and ```process_frames``` work asynchronously (called with Thread) # so that it always run as intended (for every '''interval''' sec, send a photo) # regardless of how you buffer frames as long as there are enough buffer. # They are triggered by ```start``` and halts by ```stop``` def receive_stream_packet(self): for packet in self.input_stream.demux(self.video_stream): for frame in packet.decode(): with self.frame_buffer_lock: self.frame_buffer.append(frame) time.sleep(self.capture_interval) def process_frames(self): while not self.stop_event.is_set(): current_time = time.time() if current_time - self.start_time >= self.buffer_duration: if self.last_capture_time == 0 or current_time - self.last_capture_time >= self.interval: with self.frame_buffer_lock: if self.frame_buffer: if len(self.frame_buffer) > self.buffer_size: self.frame_buffer = self.frame_buffer[-self.buffer_size:] buffered_frame = self.frame_buffer[-1] # print(len(self.frame_buffer)) self.current_frame = buffered_frame.to_image() self.current_frame = cv2.cvtColor(np.array(self.current_frame), cv2.COLOR_RGB2BGR) frame_name = f"captured_frame_{self.captured_frame_count}.jpg" img_binary = cv2.imencode('.png', self.current_frame) img_binary = img_binary[1].tobytes() self.send_image_to_server(img_binary, self.endpoint) # cv2.imwrite(f'hls_streaming/captured_frame_/{datetime.now()}_{frame_name}', img) self.last_capture_time = current_time print(f"Captured {frame_name} at time: {current_time - self.start_time:.2f}s") self.captured_frame_count +=1 time.sleep(0.1) def send_image_to_server(self, image, endpoint, image_type="png"): time_sent = datetime.now(self.time_zone).strftime("yyyy-MM-dd'T'HH:mm:ss'Z'") header = { 'Content-Type': f'image/{image_type}', 'x-time-sent': time_sent, 'x-cctv-info': str(self.cctvid), 'x-cctv-latitude' : '', 'x-cctv-longitude' : '', } try: file = { 'image': (f'frame_{self.cctvid}.{image_type}', image, f'image/{image_type}') } requests.post(endpoint, headers=header, files=file) except: print("Can not connect to the analyzer server. Check the endpoint address or connection.\n" f"Can not connect to : {self.endpoint}") def start(self): self.receive_stream_packet = Thread(target=self.receive_stream_packet) self.process_thread = Thread(target=self.process_frames) self.receive_stream_packet.start() self.process_thread.start() def stop(self): self.stop_event.set() self.receive_stream_packet.join() self.process_thread.join() self.input_stream.close() # Example usage if __name__ == "__main__": capturer = FrameCapturer( 'http://cctvsec.ktict.co.kr/71187/bWDrL7fpStZDeDZgCybpJH8gagWJOynbaA/l91ExpmUPKzc3bCsHJtIblDkzG3Tff2tHy5NNkb6NtYTbie/jNQ0F+PnejViTbKHkpMWNGpc=', 101, 10 ) t1 = time.time() try: capturer.start() time.sleep(600000) finally: capturer.stop() del capturer t2 = time.time() with open("result.txt", "w") as file: file.write(f'{t2-t1} seconds before terminating') exit()