allow detection to be disabled

Allows detection to be enabled or disabled via mqtt

fix minor mistake

fix minor bug

change how thread is started

fix some more small problems

added changes for watchdog

didnt disable watchdog and it would restart process, fixed that

change method how watchdog disabled

reinitialize watchdog when enable sent

README.md

@@ -93,6 +93,9 @@ automation:
                 caption: A person was detected.
 ```
 
+## Disabling Detection
+You can disable or enable detection via mqtt by publishing to `topic_prefix/detection` then you want to send a payload of either 'enable' or 'disable'.
+
 ## Tips
 - Lower the framerate of the video feed on the camera to reduce the CPU usage for capturing the feed
 
@@ -109,7 +112,7 @@ automation:
 - [ ] See if motion detection is even worth running
 - [ ] Scan for people across entire image rather than specfic regions
 - [ ] Dynamically resize detection area and follow people
-- [ ] Add ability to turn detection on and off via MQTT
+- [x] Add ability to turn detection on and off via MQTT
 - [ ] Output movie clips of people for notifications, etc.
 - [ ] Integrate with homeassistant push camera
 - [ ] Merge bounding boxes that span multiple regions

detect_objects.py

@@ -9,6 +9,8 @@ import paho.mqtt.client as mqtt
 from frigate.video import Camera
 from frigate.object_detection import PreppedQueueProcessor
 
+from frigate.mqtt import MqttObjectConsumer
+
 with open('/config/config.yml') as f:
     CONFIG = yaml.safe_load(f)
 
@@ -60,13 +62,25 @@ def main():
                 print ("Unable to connect to MQTT: Connection refused. Error code: " + str(rc))
         # publish a message to signal that the service is running
         client.publish(MQTT_TOPIC_PREFIX+'/available', 'online', retain=True)
+        
+    # start a thread to listen for responses over mqtt
+    listen_queue = queue.Queue(10) # since we are listening for messages shouldn't need a very large queue
+    def on_message(client, obj, msg):
+        if msg.topic.startswith(MQTT_TOPIC_PREFIX):
+            payload = str(msg.payload.decode("utf-8"))
+            listen_queue.put({
+                'topic': msg.topic,
+                'payload': payload
+            })
     client = mqtt.Client(client_id=MQTT_CLIENT_ID)
     client.on_connect = on_connect
+    client.on_message = on_message
     client.will_set(MQTT_TOPIC_PREFIX+'/available', payload='offline', qos=1, retain=True)
     if not MQTT_USER is None:
         client.username_pw_set(MQTT_USER, password=MQTT_PASS)
     client.connect(MQTT_HOST, MQTT_PORT, 60)
     client.loop_start()
+    client.subscribe("frigate/detection")
     
     # Queue for prepped frames, max size set to (number of cameras * 5)
     max_queue_size = len(CONFIG['cameras'].items())*5
@@ -76,6 +90,9 @@ def main():
     for name, config in CONFIG['cameras'].items():
         cameras[name] = Camera(name, FFMPEG_DEFAULT_CONFIG, config, prepped_frame_queue, client, MQTT_TOPIC_PREFIX)
 
+    mqtt_listener = MqttObjectConsumer(client, MQTT_TOPIC_PREFIX, listen_queue, cameras.values())
+    mqtt_listener.start()
+    
     prepped_queue_processor = PreppedQueueProcessor(
         cameras,
         prepped_frame_queue

frigate/mqtt.py

@@ -1,6 +1,7 @@
 import json
 import cv2
 import threading
+import subprocess as sp
 
 class MqttObjectPublisher(threading.Thread):
     def __init__(self, client, topic_prefix, objects_parsed, detected_objects, best_person_frame):
@@ -38,4 +39,28 @@ class MqttObjectPublisher(threading.Thread):
                     ret, jpg = cv2.imencode('.jpg', self.best_person_frame.best_frame)
                     if ret:
                         jpg_bytes = jpg.tobytes()
-                        self.client.publish(self.topic_prefix+'/snapshot', jpg_bytes, retain=True)
+                        self.client.publish(self.topic_prefix+'/snapshot', jpg_bytes, retain=True)
+                        
+class MqttObjectConsumer(threading.Thread):
+    def __init__(self, client, topic_prefix, listen_queue, cameras):
+        threading.Thread.__init__(self)
+        self.client = client
+        self.topic_prefix = topic_prefix
+        self.listen_queue = listen_queue
+        self.cameras = cameras
+        
+    def run(self):
+        while True:
+            # Now we want to see if there are more messages and then process them
+            item = self.listen_queue.get()
+            topic = item['topic']
+            payload = item['payload']
+            if topic == ("%s/detection" % self.topic_prefix):
+                if payload == 'enable':
+                    for camera in self.cameras:
+                        camera.start_or_restart_capture()
+                elif payload == 'disable':
+                    for camera in self.cameras:
+                        camera.disable_capture()
+                        camera.watchdog.disable = True
+                        camera.watchdog = None

frigate/video.py

@@ -7,6 +7,7 @@ import ctypes
 import multiprocessing as mp
 import subprocess as sp
 import numpy as np
+import queue
 from . util import tonumpyarray, draw_box_with_label
 from . object_detection import FramePrepper
 from . objects import ObjectCleaner, BestPersonFrame
@@ -63,10 +64,11 @@ class CameraWatchdog(threading.Thread):
     def __init__(self, camera):
         threading.Thread.__init__(self)
         self.camera = camera
+        self.disable = False
 
     def run(self):
 
-        while True:
+        while not self.disable:
             # wait a bit before checking
             time.sleep(10)
 
@@ -194,9 +196,10 @@ class Camera:
             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.ffmpeg_process is None:
+    def disable_capture(self):
+        if self.ffmpeg_process is None:
+            print("Attempted to disable capture but was already disabled")
+        else:
             print("Terminating the existing ffmpeg process...")
             self.ffmpeg_process.terminate()
             try:
@@ -211,6 +214,10 @@ class Camera:
             self.capture_thread.join()
             self.ffmpeg_process = None
             self.capture_thread = None
+
+    def start_or_restart_capture(self):
+        if not self.ffmpeg_process is None:
+            self.disable_capture()
             
         # create the process to capture frames from the input stream and store in a shared array
         print("Creating a new ffmpeg process...")
@@ -220,7 +227,10 @@ class Camera:
         self.capture_thread = CameraCapture(self)
         print("Starting a new capture thread...")
         self.capture_thread.start()
-    
+        
+        if self.watchdog == None:
+            self.watchdog = CameraWatchdog(self)
+            
     def start_ffmpeg(self):
         ffmpeg_cmd = (['ffmpeg'] +
             self.ffmpeg_global_args +