import os import time import datetime import cv2 import threading import ctypes import multiprocessing as mp from . util import tonumpyarray from . object_detection import FramePrepper from . objects import ObjectCleaner, ObjectParser, BestPersonFrame from . mqtt import MqttObjectPublisher # fetch the frames as fast a possible, only decoding the frames when the # detection_process has consumed the current frame def fetch_frames(shared_arr, shared_frame_time, frame_lock, frame_ready, frame_shape, rtsp_url): # convert shared memory array into numpy and shape into image array arr = tonumpyarray(shared_arr).reshape(frame_shape) # start the video capture video = cv2.VideoCapture() video.open(rtsp_url) # keep the buffer small so we minimize old data video.set(cv2.CAP_PROP_BUFFERSIZE,1) bad_frame_counter = 0 while True: # check if the video stream is still open, and reopen if needed if not video.isOpened(): success = video.open(rtsp_url) if not success: time.sleep(1) continue # grab the frame, but dont decode it yet ret = video.grab() # snapshot the time the frame was grabbed frame_time = datetime.datetime.now() if ret: # go ahead and decode the current frame ret, frame = video.retrieve() if ret: # Lock access and update frame with frame_lock: arr[:] = frame shared_frame_time.value = frame_time.timestamp() # Notify with the condition that a new frame is ready with frame_ready: frame_ready.notify_all() bad_frame_counter = 0 else: print("Unable to decode frame") bad_frame_counter += 1 else: print("Unable to grab a frame") bad_frame_counter += 1 if bad_frame_counter > 100: video.release() video.release() # Stores 2 seconds worth of frames when motion is detected so they can be used for other threads class FrameTracker(threading.Thread): def __init__(self, shared_frame, frame_time, frame_ready, frame_lock, recent_frames): threading.Thread.__init__(self) self.shared_frame = shared_frame self.frame_time = frame_time self.frame_ready = frame_ready self.frame_lock = frame_lock self.recent_frames = recent_frames def run(self): frame_time = 0.0 while True: now = datetime.datetime.now().timestamp() # wait for a frame with self.frame_ready: # if there isnt a frame ready for processing or it is old, wait for a signal if self.frame_time.value == frame_time or (now - self.frame_time.value) > 0.5: self.frame_ready.wait() # lock and make a copy of the frame with self.frame_lock: frame = self.shared_frame.copy() frame_time = self.frame_time.value # add the frame to recent frames self.recent_frames[frame_time] = frame # delete any old frames stored_frame_times = list(self.recent_frames.keys()) for k in stored_frame_times: if (now - k) > 2: del self.recent_frames[k] def get_frame_shape(rtsp_url): # capture a single frame and check the frame shape so the correct array # size can be allocated in memory video = cv2.VideoCapture(rtsp_url) ret, frame = video.read() frame_shape = frame.shape video.release() return frame_shape def get_rtsp_url(rtsp_config): if (rtsp_config['password'].startswith('$')): rtsp_config['password'] = os.getenv(rtsp_config['password'][1:]) return 'rtsp://{}:{}@{}:{}{}'.format(rtsp_config['user'], rtsp_config['password'], rtsp_config['host'], rtsp_config['port'], rtsp_config['path']) class Camera: def __init__(self, name, config, prepped_frame_queue, mqtt_client, mqtt_prefix): self.name = name self.config = config self.detected_objects = [] self.recent_frames = {} self.rtsp_url = get_rtsp_url(self.config['rtsp']) self.regions = self.config['regions'] self.frame_shape = get_frame_shape(self.rtsp_url) self.mqtt_client = mqtt_client self.mqtt_topic_prefix = '{}/{}'.format(mqtt_prefix, self.name) # compute the flattened array length from the shape of the frame flat_array_length = self.frame_shape[0] * self.frame_shape[1] * self.frame_shape[2] # create shared array for storing the full frame image data self.shared_frame_array = mp.Array(ctypes.c_uint8, flat_array_length) # create shared value for storing the frame_time self.shared_frame_time = mp.Value('d', 0.0) # Lock to control access to the frame self.frame_lock = mp.Lock() # Condition for notifying that a new frame is ready self.frame_ready = mp.Condition() # Condition for notifying that objects were parsed self.objects_parsed = mp.Condition() # shape current frame so it can be treated as a numpy image self.shared_frame_np = tonumpyarray(self.shared_frame_array).reshape(self.frame_shape) # create the process to capture frames from the RTSP stream and store in a shared array self.capture_process = mp.Process(target=fetch_frames, args=(self.shared_frame_array, self.shared_frame_time, self.frame_lock, self.frame_ready, self.frame_shape, self.rtsp_url)) self.capture_process.daemon = True # for each region, create a separate thread to resize the region and prep for detection self.detection_prep_threads = [] for region in self.config['regions']: self.detection_prep_threads.append(FramePrepper( self.name, self.shared_frame_np, self.shared_frame_time, self.frame_ready, self.frame_lock, region['size'], region['x_offset'], region['y_offset'], prepped_frame_queue )) # start a thread to store recent motion frames for processing self.frame_tracker = FrameTracker(self.shared_frame_np, self.shared_frame_time, self.frame_ready, self.frame_lock, self.recent_frames) self.frame_tracker.start() # start a thread to store the highest scoring recent person frame self.best_person_frame = BestPersonFrame(self.objects_parsed, self.recent_frames, self.detected_objects) self.best_person_frame.start() # start a thread to expire objects from the detected objects list self.object_cleaner = ObjectCleaner(self.objects_parsed, self.detected_objects) self.object_cleaner.start() # start a thread to publish object scores (currently only person) mqtt_publisher = MqttObjectPublisher(self.mqtt_client, self.mqtt_topic_prefix, self.objects_parsed, self.detected_objects) mqtt_publisher.start() def start(self): self.capture_process.start() # start the object detection prep threads for detection_prep_thread in self.detection_prep_threads: detection_prep_thread.start() def join(self): self.capture_process.join() def get_capture_pid(self): return self.capture_process.pid def add_objects(self, objects): if len(objects) == 0: return for obj in objects: if obj['name'] == 'person': person_area = (obj['xmax']-obj['xmin'])*(obj['ymax']-obj['ymin']) # find the matching region region = None for r in self.regions: if ( obj['xmin'] >= r['x_offset'] and obj['ymin'] >= r['y_offset'] and obj['xmax'] <= r['x_offset']+r['size'] and obj['ymax'] <= r['y_offset']+r['size'] ): region = r break # if the min person area is larger than the # detected person, don't add it to detected objects if region and region['min_person_area'] > person_area: continue self.detected_objects.append(obj) with self.objects_parsed: self.objects_parsed.notify_all() def get_best_person(self): return self.best_person_frame.best_frame