blakeblackshear.frigate/frigate/objects.py

import time
import datetime
import threading
import cv2
from . util import draw_box_with_label

class ObjectCleaner(threading.Thread):
    def __init__(self, objects_parsed, detected_objects):
        threading.Thread.__init__(self)
        self._objects_parsed = objects_parsed
        self._detected_objects = detected_objects

    def run(self):
        while True:

            # wait a bit before checking for expired frames
            time.sleep(0.2)

            # expire the objects that are more than 1 second old
            now = datetime.datetime.now().timestamp()
            # look for the first object found within the last second
            # (newest objects are appended to the end)
            detected_objects = self._detected_objects.copy()

            num_to_delete = 0
            for obj in detected_objects:
                if now-obj['frame_time']<2:
                    break
                num_to_delete += 1
            if num_to_delete > 0:
                del self._detected_objects[:num_to_delete]

                # notify that parsed objects were changed
                with self._objects_parsed:
                    self._objects_parsed.notify_all()


# Maintains the frame and person with the highest score from the most recent
# motion event
class BestPersonFrame(threading.Thread):
    def __init__(self, objects_parsed, recent_frames, detected_objects):
        threading.Thread.__init__(self)
        self.objects_parsed = objects_parsed
        self.recent_frames = recent_frames
        self.detected_objects = detected_objects
        self.best_person = None
        self.best_frame = None

    def run(self):
        while True:

            # wait until objects have been parsed
            with self.objects_parsed:
                self.objects_parsed.wait()

            # make a copy of detected objects
            detected_objects = self.detected_objects.copy()
            detected_people = [obj for obj in detected_objects if obj['name'] == 'person']

            # get the highest scoring person
            new_best_person = max(detected_people, key=lambda x:x['score'], default=self.best_person)

            # if there isnt a person, continue
            if new_best_person is None:
                continue

            # if there is no current best_person
            if self.best_person is None:
                self.best_person = new_best_person
            # if there is already a best_person
            else:
                now = datetime.datetime.now().timestamp()
                # if the new best person is a higher score than the current best person 
                # or the current person is more than 1 minute old, use the new best person
                if new_best_person['score'] > self.best_person['score'] or (now - self.best_person['frame_time']) > 60:
                    self.best_person = new_best_person
            
            # make a copy of the recent frames
            recent_frames = self.recent_frames.copy()
            
            if not self.best_person is None and self.best_person['frame_time'] in recent_frames:
                best_frame = recent_frames[self.best_person['frame_time']]

                label = "{}: {}% {}".format(self.best_person['name'],int(self.best_person['score']*100),int(self.best_person['area']))
                draw_box_with_label(best_frame, self.best_person['xmin'], self.best_person['ymin'], 
                    self.best_person['xmax'], self.best_person['ymax'], label)
                
                # print a timestamp
                time_to_show = datetime.datetime.fromtimestamp(self.best_person['frame_time']).strftime("%m/%d/%Y %H:%M:%S")
                cv2.putText(best_frame, time_to_show, (10, 30), cv2.FONT_HERSHEY_SIMPLEX, fontScale=.8, color=(255, 255, 255), thickness=2)
                
                self.best_frame = cv2.cvtColor(best_frame, cv2.COLOR_RGB2BGR)