frigate/frigate/video.py

289 lines
11 KiB
Python

import os
import time
import datetime
import cv2
import threading
import ctypes
import multiprocessing as mp
import subprocess as sp
import numpy as np
import ffmpeg
from . util import tonumpyarray, draw_box_with_label
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)
frame_size = frame_shape[0] * frame_shape[1] * frame_shape[2]
ffmpeg_cmd = ['ffmpeg',
'-avoid_negative_ts', 'make_zero',
'-fflags', '+genpts',
'-rtsp_transport', 'tcp',
'-stimeout', '5000000',
'-use_wallclock_as_timestamps', '1',
'-i', rtsp_url,
'-f', 'rawvideo',
'-pix_fmt', 'rgb24',
'pipe:']
pipe = sp.Popen(ffmpeg_cmd, stdout = sp.PIPE, bufsize=frame_size)
while True:
raw_image = pipe.stdout.read(frame_size)
frame = (
np
.frombuffer(raw_image, np.uint8)
.reshape(frame_shape)
)
with frame_lock:
shared_frame_time.value = datetime.datetime.now().timestamp()
arr[:] = frame
# Notify with the condition that a new frame is ready
with frame_ready:
frame_ready.notify_all()
pipe.stdout.flush()
# 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 CameraWatchdog(threading.Thread):
def __init__(self, camera):
threading.Thread.__init__(self)
self.camera = camera
def run(self):
while True:
# wait a bit before checking
time.sleep(60)
if (datetime.datetime.now().timestamp() - self.camera.shared_frame_time.value) > 2:
print("last frame is more than 2 seconds old, restarting camera capture...")
self.camera.start_or_restart_capture()
time.sleep(5)
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)
self.capture_process = None
# 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']:
# set a default threshold of 0.5 if not defined
if not 'threshold' in region:
region['threshold'] = 0.5
if not isinstance(region['threshold'], float):
print('Threshold is not a float. Setting to 0.5 default.')
region['threshold'] = 0.5
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'], region['threshold'],
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()
# create a watchdog thread for capture process
self.watchdog = CameraWatchdog(self)
# load in the mask for person detection
if 'mask' in self.config:
self.mask = cv2.imread("/config/{}".format(self.config['mask']), cv2.IMREAD_GRAYSCALE)
else:
self.mask = np.zeros((self.frame_shape[0], self.frame_shape[1], 1), np.uint8)
self.mask[:] = 255
def start_or_restart_capture(self):
if not self.capture_process is None:
print("Terminating the existing capture process...")
self.capture_process.terminate()
del self.capture_process
self.capture_process = None
# create the process to capture frames from the RTSP stream and store in a shared array
print("Creating a new capture process...")
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
print("Starting a new capture process...")
self.capture_process.start()
def start(self):
self.start_or_restart_capture()
# start the object detection prep threads
for detection_prep_thread in self.detection_prep_threads:
detection_prep_thread.start()
self.watchdog.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
# compute the coordinates of the person and make sure
# the location isnt outide the bounds of the image (can happen from rounding)
y_location = min(int(obj['ymax']), len(self.mask)-1)
x_location = min(int((obj['xmax']-obj['xmin'])/2.0), len(self.mask[0])-1)
# if the person is in a masked location, continue
if self.mask[y_location][x_location] == [0]:
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()
# draw the bounding boxes on the screen
for obj in detected_objects:
label = "{}: {}%".format(obj['name'],int(obj['score']*100))
draw_box_with_label(frame, obj['xmin'], obj['ymin'], obj['xmax'], obj['ymax'], label)
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 to BGR
frame = cv2.cvtColor(frame, cv2.COLOR_RGB2BGR)
return frame