blakeblackshear.frigate/frigate/video.py
2019-04-14 11:28:50 -05:00

311 lines
12 KiB
Python

import os
import time
import datetime
import cv2
import threading
import ctypes
import multiprocessing as mp
import numpy as np
from object_detection.utils import visualization_utils as vis_util
from . util import tonumpyarray
from . object_detection import FramePrepper
from . objects import ObjectCleaner, BestPersonFrame
from . mqtt import MqttObjectPublisher
# fetch the frames as fast a possible and store current frame in a shared memory array
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'])
def compute_sizes(frame_shape, known_sizes, mask):
# create a 3 dimensional numpy array to store estimated sizes
estimated_sizes = np.zeros((frame_shape[0], frame_shape[1], 2), np.uint32)
sorted_positions = sorted(known_sizes, key=lambda s: s['y'])
last_position = {'y': 0, 'min': 0, 'max': 0}
next_position = sorted_positions.pop(0)
# if the next position has the same y coordinate, skip
while next_position['y'] == last_position['y']:
next_position = sorted_positions.pop(0)
y_change = next_position['y']-last_position['y']
min_size_change = next_position['min']-last_position['min']
max_size_change = next_position['max']-last_position['max']
min_step_size = min_size_change/y_change
max_step_size = max_size_change/y_change
min_current_size = 0
max_current_size = 0
for y_position in range(frame_shape[0]):
# fill the row with the estimated size
estimated_sizes[y_position,:] = [min_current_size, max_current_size]
# if you have reached the next size
if y_position == next_position['y']:
last_position = next_position
# if there are still positions left
if len(sorted_positions) > 0:
next_position = sorted_positions.pop(0)
# if the next position has the same y coordinate, skip
while next_position['y'] == last_position['y']:
next_position = sorted_positions.pop(0)
y_change = next_position['y']-last_position['y']
min_size_change = next_position['min']-last_position['min']
max_size_change = next_position['max']-last_position['max']
min_step_size = min_size_change/y_change
max_step_size = max_size_change/y_change
else:
min_step_size = 0
max_step_size = 0
min_current_size += min_step_size
max_current_size += max_step_size
# apply mask by filling 0s for all locations a person could not be standing
if mask is not None:
pass
return estimated_sizes
class Camera:
def __init__(self, name, config, prepped_frame_queue, mqtt_client, mqtt_prefix, debug=False):
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)
self.debug = debug
# 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()
# pre-compute estimated person size for every pixel in the image
if 'known_sizes' in self.config:
self.calculated_person_sizes = compute_sizes((self.frame_shape[0], self.frame_shape[1]),
self.config['known_sizes'], None)
else:
self.calculated_person_sizes = None
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 self.debug:
# print out the detected objects, scores and locations
print(self.name, obj['name'], obj['score'], obj['xmin'], obj['ymin'], obj['xmax'], obj['ymax'])
if self.calculated_person_sizes is not None and obj['name'] == 'person':
standing_location = (int(obj['ymax']), int((obj['xmax']-obj['xmin'])/2))
person_size_range = self.calculated_person_sizes[standing_location[0]][standing_location[1]]
# if the person isnt on the ground, continue
if(person_size_range[0] == 0 and person_size_range[1] == 0):
continue
person_size = (obj['xmax']-obj['xmin'])*(obj['ymax']-obj['ymin'])
# if the person is not within 20% of the estimated size for that location, continue
if person_size < person_size_range[0] or person_size > person_size_range[1]:
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
def get_current_frame_with_objects(self):
# make a copy of the current detected objects
detected_objects = self.detected_objects.copy()
# lock and make a copy of the current frame
with self.frame_lock:
frame = self.shared_frame_np.copy()
# convert to RGB for drawing
frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
# draw the bounding boxes on the screen
for obj in detected_objects:
vis_util.draw_bounding_box_on_image_array(frame,
obj['ymin'],
obj['xmin'],
obj['ymax'],
obj['xmax'],
color='red',
thickness=2,
display_str_list=["{}: {}%".format(obj['name'],int(obj['score']*100))],
use_normalized_coordinates=False)
for region in self.regions:
color = (255,255,255)
cv2.rectangle(frame, (region['x_offset'], region['y_offset']),
(region['x_offset']+region['size'], region['y_offset']+region['size']),
color, 2)
# convert back to BGR
frame = cv2.cvtColor(frame, cv2.COLOR_RGB2BGR)
return frame