move ffmpeg capture to a separate thread and use a queue

detect_objects.py

@@ -15,7 +15,7 @@ import logging
 from flask import Flask, Response, make_response, jsonify, request
 import paho.mqtt.client as mqtt
 
-from frigate.video import track_camera
+from frigate.video import track_camera, get_ffmpeg_input, get_frame_shape, CameraCapture, start_or_restart_ffmpeg
 from frigate.object_processing import TrackedObjectProcessor
 from frigate.util import EventsPerSecond
 from frigate.edgetpu import EdgeTPUProcess
@@ -83,60 +83,50 @@ class CameraWatchdog(threading.Thread):
         time.sleep(10)
         while True:
             # wait a bit before checking
-            time.sleep(30)
+            time.sleep(10)
             
             # check the plasma process
             rc = self.plasma_process.poll()
             if rc != None:
                 print(f"plasma_process exited unexpectedly with {rc}")
                 self.plasma_process = start_plasma_store()
-                time.sleep(10)
 
             # check the detection process
             if (self.tflite_process.detection_start.value > 0.0 and 
                 datetime.datetime.now().timestamp() - self.tflite_process.detection_start.value > 10):
                 print("Detection appears to be stuck. Restarting detection process")
                 self.tflite_process.start_or_restart()
-                time.sleep(30)
             elif not self.tflite_process.detect_process.is_alive():
                 print("Detection appears to have stopped. Restarting detection process")
                 self.tflite_process.start_or_restart()
-                time.sleep(30)
 
             # check the camera processes
             for name, camera_process in self.camera_processes.items():
                 process = camera_process['process']
                 if not process.is_alive():
-                    print(f"Process for {name} is not alive. Starting again...")
+                    print(f"Track process for {name} is not alive. Starting again...")
                     camera_process['fps'].value = float(self.config[name]['fps'])
                     camera_process['skipped_fps'].value = 0.0
                     camera_process['detection_fps'].value = 0.0
                     camera_process['read_start'].value = 0.0
-                    camera_process['ffmpeg_pid'].value = 0
-                    process = mp.Process(target=track_camera, args=(name, self.config[name], FFMPEG_DEFAULT_CONFIG, GLOBAL_OBJECT_CONFIG, 
-                        self.tflite_process.detection_queue, self.tracked_objects_queue, 
+                    process = mp.Process(target=track_camera, args=(name, self.config[name], GLOBAL_OBJECT_CONFIG, camera_process['frame_queue'],
+                        camera_process['frame_shape'], self.tflite_process.detection_queue, self.tracked_objects_queue, 
                         camera_process['fps'], camera_process['skipped_fps'], camera_process['detection_fps'],
-                        camera_process['read_start'], camera_process['ffmpeg_pid']))
+                        camera_process['read_start']))
                     process.daemon = True
                     camera_process['process'] = process
                     process.start()
-                    print(f"Camera_process started for {name}: {process.pid}")
-
-                if (camera_process['read_start'].value > 0.0 and 
-                    datetime.datetime.now().timestamp() - camera_process['read_start'].value > 10):
-                    print(f"Process for {name} has been reading from ffmpeg for over 10 seconds long. Killing ffmpeg...")
-                    ffmpeg_pid = camera_process['ffmpeg_pid'].value
-                    if ffmpeg_pid != 0:
-                        try:
-                            os.kill(ffmpeg_pid, signal.SIGTERM)
-                        except OSError:
-                            print(f"Unable to terminate ffmpeg with pid {ffmpeg_pid}")
-                        time.sleep(10)
-                        try:
-                            os.kill(ffmpeg_pid, signal.SIGKILL)
-                            print(f"Unable to kill ffmpeg with pid {ffmpeg_pid}")
-                        except OSError:
-                            pass
+                    print(f"Track process started for {name}: {process.pid}")
+                
+                if not camera_process['capture_thread'].is_alive():
+                    frame_shape = camera_process['frame_shape']
+                    frame_size = frame_shape[0] * frame_shape[1] * frame_shape[2]
+                    ffmpeg_process = start_or_restart_ffmpeg(camera_process['ffmpeg_cmd'], frame_size)
+                    camera_capture = CameraCapture(name, ffmpeg_process, frame_shape, camera_process['frame_queue'], 
+                        camera_process['take_frame'], camera_process['camera_fps'])
+                    camera_capture.start()
+                    camera_process['ffmpeg_process'] = ffmpeg_process
+                    camera_process['capture_thread'] = camera_capture
 
 def main():
     # connect to mqtt and setup last will
@@ -180,17 +170,54 @@ def main():
     # start the camera processes
     camera_processes = {}
     for name, config in CONFIG['cameras'].items():
+        # Merge the ffmpeg config with the global config
+        ffmpeg = config.get('ffmpeg', {})
+        ffmpeg_input = get_ffmpeg_input(ffmpeg['input'])
+        ffmpeg_global_args = ffmpeg.get('global_args', FFMPEG_DEFAULT_CONFIG['global_args'])
+        ffmpeg_hwaccel_args = ffmpeg.get('hwaccel_args', FFMPEG_DEFAULT_CONFIG['hwaccel_args'])
+        ffmpeg_input_args = ffmpeg.get('input_args', FFMPEG_DEFAULT_CONFIG['input_args'])
+        ffmpeg_output_args = ffmpeg.get('output_args', FFMPEG_DEFAULT_CONFIG['output_args'])
+        ffmpeg_cmd = (['ffmpeg'] +
+                ffmpeg_global_args +
+                ffmpeg_hwaccel_args +
+                ffmpeg_input_args +
+                ['-i', ffmpeg_input] +
+                ffmpeg_output_args +
+                ['pipe:'])
+        
+        if 'width' in config and 'height' in config:
+            frame_shape = (config['height'], config['width'], 3)
+        else:
+            frame_shape = get_frame_shape(ffmpeg_input)
+
+        frame_size = frame_shape[0] * frame_shape[1] * frame_shape[2]
+        take_frame = config.get('take_frame', 1)
+
+        ffmpeg_process = start_or_restart_ffmpeg(ffmpeg_cmd, frame_size)
+        frame_queue = mp.SimpleQueue()
+        camera_fps = EventsPerSecond()
+        camera_fps.start()
+        camera_capture = CameraCapture(name, ffmpeg_process, frame_shape, frame_queue, take_frame, camera_fps)
+        camera_capture.start()
+
         camera_processes[name] = {
+            'camera_fps': camera_fps,
+            'take_frame': take_frame,
             'fps': mp.Value('d', float(config['fps'])),
             'skipped_fps': mp.Value('d', 0.0),
             'detection_fps': mp.Value('d', 0.0),
             'read_start': mp.Value('d', 0.0),
-            'ffmpeg_pid': mp.Value('i', 0)
+            'ffmpeg_process': ffmpeg_process,
+            'ffmpeg_cmd': ffmpeg_cmd,
+            'frame_queue': frame_queue,
+            'frame_shape': frame_shape,
+            'capture_thread': camera_capture
         }
-        camera_process = mp.Process(target=track_camera, args=(name, config, FFMPEG_DEFAULT_CONFIG, GLOBAL_OBJECT_CONFIG, 
+
+        camera_process = mp.Process(target=track_camera, args=(name, config, GLOBAL_OBJECT_CONFIG, frame_queue, frame_shape,
             tflite_process.detection_queue, tracked_objects_queue, camera_processes[name]['fps'], 
             camera_processes[name]['skipped_fps'], camera_processes[name]['detection_fps'], 
-            camera_processes[name]['read_start'], camera_processes[name]['ffmpeg_pid']))
+            camera_processes[name]['read_start']))
         camera_process.daemon = True
         camera_processes[name]['process'] = camera_process
 
@@ -245,7 +272,7 @@ def main():
                 'detection_fps': round(camera_stats['detection_fps'].value, 2),
                 'read_start': camera_stats['read_start'].value,
                 'pid': camera_stats['process'].pid,
-                'ffmpeg_pid': camera_stats['ffmpeg_pid'].value
+                'ffmpeg_pid': camera_stats['ffmpeg_process'].pid
             }
         
         stats['coral'] = {
@@ -302,7 +329,7 @@ def main():
 
     app.run(host='0.0.0.0', port=WEB_PORT, debug=False)
 
-    camera_watchdog.join()
+    object_processor.join()
     
     plasma_process.terminate()
 

frigate/object_processing.py

@@ -10,7 +10,7 @@ from collections import Counter, defaultdict
 import itertools
 import pyarrow.plasma as plasma
 import matplotlib.pyplot as plt
-from frigate.util import draw_box_with_label
+from frigate.util import draw_box_with_label, PlasmaManager
 from frigate.edgetpu import load_labels
 
 PATH_TO_LABELS = '/labelmap.txt'
@@ -36,6 +36,7 @@ class TrackedObjectProcessor(threading.Thread):
             'current_frame': np.zeros((720,1280,3), np.uint8),
             'object_id': None
         })
+        self.plasma_client = PlasmaManager()
         
     def get_best(self, camera, label):
         if label in self.camera_data[camera]['best_objects']:
@@ -45,35 +46,8 @@ class TrackedObjectProcessor(threading.Thread):
     
     def get_current_frame(self, camera):
         return self.camera_data[camera]['current_frame']
-    
-    def connect_plasma_client(self):
-        while True:
-            try:
-                self.plasma_client = plasma.connect("/tmp/plasma")
-                return
-            except:
-                print(f"TrackedObjectProcessor: unable to connect plasma client")
-                time.sleep(10)
-    
-    def get_from_plasma(self, object_id):
-        while True:
-            try:
-                return self.plasma_client.get(object_id, timeout_ms=0)
-            except:
-                self.connect_plasma_client()
-                time.sleep(1)
-    
-    def delete_from_plasma(self, object_ids):
-        while True:
-            try:
-                self.plasma_client.delete(object_ids)
-                return
-            except:
-                self.connect_plasma_client()
-                time.sleep(1)
 
     def run(self):
-        self.connect_plasma_client()
         while True:
             camera, frame_time, tracked_objects = self.tracked_objects_queue.get()
 
@@ -85,10 +59,7 @@ class TrackedObjectProcessor(threading.Thread):
             ###
             # Draw tracked objects on the frame
             ###
-            object_id_hash = hashlib.sha1(str.encode(f"{camera}{frame_time}"))
-            object_id_bytes = object_id_hash.digest()
-            object_id = plasma.ObjectID(object_id_bytes)
-            current_frame = self.get_from_plasma(object_id)
+            current_frame = self.plasma_client.get(f"{camera}{frame_time}")
 
             if not current_frame is plasma.ObjectNotAvailable:
                 # draw the bounding boxes on the frame
@@ -117,10 +88,10 @@ class TrackedObjectProcessor(threading.Thread):
                 self.camera_data[camera]['current_frame'] = current_frame
 
                 # store the object id, so you can delete it at the next loop
-                previous_object_id = self.camera_data[camera]['object_id']
+                previous_object_id = f"{camera}{frame_time}"
                 if not previous_object_id is None:
-                    self.delete_from_plasma([previous_object_id])
-                self.camera_data[camera]['object_id'] = object_id
+                    self.plasma_client.delete(f"{camera}{frame_time}")
+                self.camera_data[camera]['object_id'] = f"{camera}{frame_time}"
             
             ###
             # Maintain the highest scoring recent object and frame for each label

frigate/util.py

@@ -1,4 +1,5 @@
 import datetime
+import time
 import signal
 import traceback
 import collections
@@ -6,6 +7,8 @@ import numpy as np
 import cv2
 import threading
 import matplotlib.pyplot as plt
+import hashlib
+import pyarrow.plasma as plasma
 
 def draw_box_with_label(frame, x_min, y_min, x_max, y_max, label, info, thickness=2, color=None, position='ul'):
     if color is None:
@@ -134,4 +137,47 @@ def print_stack(sig, frame):
     traceback.print_stack(frame)
 
 def listen():
-    signal.signal(signal.SIGUSR1, print_stack)
+    signal.signal(signal.SIGUSR1, print_stack)
+
+class PlasmaManager:
+    def __init__(self):
+        self.connect()
+    
+    def connect(self):
+        while True:
+            try:
+                self.plasma_client = plasma.connect("/tmp/plasma")
+                return
+            except:
+                print(f"TrackedObjectProcessor: unable to connect plasma client")
+                time.sleep(10)
+
+    def get(self, name, timeout_ms=0):
+        object_id = plasma.ObjectID(hashlib.sha1(str.encode(name)).digest())
+        while True:
+            try:
+                return self.plasma_client.get(object_id, timeout_ms=timeout_ms)
+            except:
+                self.connect()
+                time.sleep(1)
+
+    def put(self, name, obj):
+        object_id = plasma.ObjectID(hashlib.sha1(str.encode(name)).digest())
+        while True:
+            try:
+                self.plasma_client.put(obj, object_id)
+                return
+            except Exception as e:
+                print(f"Failed to put in plasma: {e}")
+                self.connect()
+                time.sleep(1)
+
+    def delete(self, name):
+        object_id = plasma.ObjectID(hashlib.sha1(str.encode(name)).digest())
+        while True:
+            try:
+                self.plasma_client.delete([object_id])
+                return
+            except:
+                self.connect()
+                time.sleep(1)

frigate/video.py

@@ -5,16 +5,15 @@ import cv2
 import queue
 import threading
 import ctypes
+import pyarrow.plasma as plasma
 import multiprocessing as mp
 import subprocess as sp
 import numpy as np
-import hashlib
-import pyarrow.plasma as plasma
 import copy
 import itertools
 import json
 from collections import defaultdict
-from frigate.util import draw_box_with_label, area, calculate_region, clipped, intersection_over_union, intersection, EventsPerSecond, listen
+from frigate.util import draw_box_with_label, area, calculate_region, clipped, intersection_over_union, intersection, EventsPerSecond, listen, PlasmaManager
 from frigate.objects import ObjectTracker
 from frigate.edgetpu import RemoteObjectDetector
 from frigate.motion import MotionDetector
@@ -97,7 +96,7 @@ def create_tensor_input(frame, region):
     # Expand dimensions since the model expects images to have shape: [1, 300, 300, 3]
     return np.expand_dims(cropped_frame, axis=0)
 
-def start_or_restart_ffmpeg(ffmpeg_cmd, frame_size, pid, ffmpeg_process=None):
+def start_or_restart_ffmpeg(ffmpeg_cmd, frame_size, ffmpeg_process=None):
     if not ffmpeg_process is None:
         print("Terminating the existing ffmpeg process...")
         ffmpeg_process.terminate()
@@ -112,30 +111,54 @@ def start_or_restart_ffmpeg(ffmpeg_cmd, frame_size, pid, ffmpeg_process=None):
 
     print("Creating ffmpeg process...")
     print(" ".join(ffmpeg_cmd))
-    process = sp.Popen(ffmpeg_cmd, stdout = sp.PIPE, bufsize=frame_size*10)
-    pid.value = process.pid
+    process = sp.Popen(ffmpeg_cmd, stdout = sp.PIPE, stdin = sp.DEVNULL, bufsize=frame_size*10, start_new_session=True)
     return process
 
-def track_camera(name, config, ffmpeg_global_config, global_objects_config, detection_queue, detected_objects_queue, fps, skipped_fps, detection_fps, read_start, ffmpeg_pid):
+class CameraCapture(threading.Thread):
+    def __init__(self, name, ffmpeg_process, frame_shape, frame_queue, take_frame, fps):
+        threading.Thread.__init__(self)
+        self.name = name
+        self.frame_shape = frame_shape
+        self.frame_size = frame_shape[0] * frame_shape[1] * frame_shape[2]
+        self.frame_queue = frame_queue
+        self.take_frame = take_frame
+        self.fps = fps
+        self.plasma_client = PlasmaManager()
+        self.ffmpeg_process = ffmpeg_process
+
+    def run(self):
+        frame_num = 0
+        while True:
+            if self.ffmpeg_process.poll() != None:
+                print(f"{self.name}: ffmpeg process is not running. exiting capture thread...")
+                break
+
+            frame_bytes = self.ffmpeg_process.stdout.read(self.frame_size)
+            frame_time = datetime.datetime.now().timestamp()
+
+            if len(frame_bytes) == 0:
+                print(f"{self.name}: ffmpeg didnt return a frame. something is wrong.")
+                continue
+
+            frame_num += 1
+            if (frame_num % self.take_frame) != 0:
+                continue
+
+            # put the frame in the plasma store
+            self.plasma_client.put(f"{self.name}{frame_time}",
+                    np
+                        .frombuffer(frame_bytes, np.uint8)
+                        .reshape(self.frame_shape)
+                )
+            # add to the queue
+            self.frame_queue.put(frame_time)
+
+            self.fps.update()
+
+def track_camera(name, config, global_objects_config, frame_queue, frame_shape, detection_queue, detected_objects_queue, fps, skipped_fps, detection_fps, read_start):
     print(f"Starting process for {name}: {os.getpid()}")
     listen()
 
-    # Merge the ffmpeg config with the global config
-    ffmpeg = config.get('ffmpeg', {})
-    ffmpeg_input = get_ffmpeg_input(ffmpeg['input'])
-    ffmpeg_restart_delay = ffmpeg.get('restart_delay', 0)
-    ffmpeg_global_args = ffmpeg.get('global_args', ffmpeg_global_config['global_args'])
-    ffmpeg_hwaccel_args = ffmpeg.get('hwaccel_args', ffmpeg_global_config['hwaccel_args'])
-    ffmpeg_input_args = ffmpeg.get('input_args', ffmpeg_global_config['input_args'])
-    ffmpeg_output_args = ffmpeg.get('output_args', ffmpeg_global_config['output_args'])
-    ffmpeg_cmd = (['ffmpeg'] +
-            ffmpeg_global_args +
-            ffmpeg_hwaccel_args +
-            ffmpeg_input_args +
-            ['-i', ffmpeg_input] +
-            ffmpeg_output_args +
-            ['pipe:'])
-
     # Merge the tracked object config with the global config
     camera_objects_config = config.get('objects', {})    
     # combine tracked objects lists
@@ -149,14 +172,6 @@ def track_camera(name, config, ffmpeg_global_config, global_objects_config, dete
         object_filters[obj] = {**global_object_filters.get(obj, {}), **camera_object_filters.get(obj, {})}
 
     expected_fps = config['fps']
-    take_frame = config.get('take_frame', 1)
-
-    if 'width' in config and 'height' in config:
-        frame_shape = (config['height'], config['width'], 3)
-    else:
-        frame_shape = get_frame_shape(ffmpeg_input)
-
-    frame_size = frame_shape[0] * frame_shape[1] * frame_shape[2]
 
     frame = np.zeros(frame_shape, np.uint8)
 
@@ -174,10 +189,8 @@ def track_camera(name, config, ffmpeg_global_config, global_objects_config, dete
     object_detector = RemoteObjectDetector(name, '/labelmap.txt', detection_queue)
 
     object_tracker = ObjectTracker(10)
-    
-    ffmpeg_process = start_or_restart_ffmpeg(ffmpeg_cmd, frame_size, ffmpeg_pid)
-    
-    plasma_client = plasma.connect("/tmp/plasma")
+
+    plasma_client = PlasmaManager()
     frame_num = 0
     avg_wait = 0.0
     fps_tracker = EventsPerSecond()
@@ -186,39 +199,23 @@ def track_camera(name, config, ffmpeg_global_config, global_objects_config, dete
     skipped_fps_tracker.start()
     object_detector.fps.start()
     while True:
-        rc = ffmpeg_process.poll()
-        if rc != None:
-            print(f"{name}: ffmpeg_process exited unexpectedly with {rc}")
-            print(f"Letting {name} rest for {ffmpeg_restart_delay} seconds before restarting...")
-            time.sleep(ffmpeg_restart_delay)
-            ffmpeg_process = start_or_restart_ffmpeg(ffmpeg_cmd, frame_size, ffmpeg_pid, ffmpeg_process)
-            time.sleep(10)
-
         read_start.value = datetime.datetime.now().timestamp()
-        frame_bytes = ffmpeg_process.stdout.read(frame_size)
+        frame_time = frame_queue.get()
         duration = datetime.datetime.now().timestamp()-read_start.value
         read_start.value = 0.0
         avg_wait = (avg_wait*99+duration)/100
 
-        if len(frame_bytes) == 0:
-            print(f"{name}: ffmpeg_process didnt return any bytes")
-            continue
-
-        # limit frame rate
-        frame_num += 1
-        if (frame_num % take_frame) != 0:
-            continue
-
         fps_tracker.update()
         fps.value = fps_tracker.eps()
         detection_fps.value = object_detector.fps.eps()
-
-        frame_time = datetime.datetime.now().timestamp()
         
-        # Store frame in numpy array
-        frame[:] = (np
-                    .frombuffer(frame_bytes, np.uint8)
-                    .reshape(frame_shape))
+        # Get frame from plasma store
+        frame = plasma_client.get(f"{name}{frame_time}")
+
+        if frame is plasma.ObjectNotAvailable:
+            skipped_fps_tracker.update()
+            skipped_fps.value = skipped_fps_tracker.eps()
+            continue
         
         # look for motion
         motion_boxes = motion_detector.detect(frame)
@@ -227,6 +224,7 @@ def track_camera(name, config, ffmpeg_global_config, global_objects_config, dete
         if frame_num > 100 and fps.value < expected_fps-1 and duration < 0.5*avg_wait:
             skipped_fps_tracker.update()
             skipped_fps.value = skipped_fps_tracker.eps()
+            plasma_client.delete(f"{name}{frame_time}")
             continue
         
         skipped_fps.value = skipped_fps_tracker.eps()
@@ -330,7 +328,7 @@ def track_camera(name, config, ffmpeg_global_config, global_objects_config, dete
 
                 for index in idxs:
                     obj = group[index[0]]
-                    if clipped(obj, frame_shape): #obj['clipped']:
+                    if clipped(obj, frame_shape):
                         box = obj[2]
                         # calculate a new region that will hopefully get the entire object
                         region = calculate_region(frame_shape, 
@@ -370,9 +368,6 @@ def track_camera(name, config, ffmpeg_global_config, global_objects_config, dete
         # now that we have refined our detections, we need to track objects
         object_tracker.match_and_update(frame_time, detections)
 
-        # put the frame in the plasma store
-        object_id = hashlib.sha1(str.encode(f"{name}{frame_time}")).digest()
-        plasma_client.put(frame, plasma.ObjectID(object_id))
         # add to the queue
         detected_objects_queue.put((name, frame_time, object_tracker.tracked_objects))