blakeblackshear.frigate/frigate/video.py
2019-07-30 19:11:22 -05:00

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
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',
'-hide_banner', '-loglevel', 'panic',
'-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