skip frames in the capture thread instead

config/config.example.yml

@@ -110,13 +110,6 @@ cameras:
     ################
     take_frame: 1
 
-    ################
-    # The expected framerate for the camera. Frigate will try and ensure it maintains this framerate
-    # by dropping frames as necessary. Setting this lower than the actual framerate will allow frigate
-    # to process every frame at the expense of realtime processing.
-    ################
-    fps: 5
-
     ################
     # Configuration for the snapshots in the debug view and mqtt
     ################

detect_objects.py

@@ -105,14 +105,13 @@ class CameraWatchdog(threading.Thread):
                 process = camera_process['process']
                 if not process.is_alive():
                     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['process_fps'].value = 0.0
                     camera_process['detection_fps'].value = 0.0
                     camera_process['read_start'].value = 0.0
                     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['process_fps'], camera_process['detection_fps'],
+                        camera_process['read_start'], camera_process['detection_frame']))
                     process.daemon = True
                     camera_process['process'] = process
                     process.start()
@@ -123,7 +122,7 @@ class CameraWatchdog(threading.Thread):
                     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_process['take_frame'], camera_process['camera_fps'], camera_process['detection_frame'])
                     camera_capture.start()
                     camera_process['ffmpeg_process'] = ffmpeg_process
                     camera_process['capture_thread'] = camera_capture
@@ -193,20 +192,21 @@ def main():
         frame_size = frame_shape[0] * frame_shape[1] * frame_shape[2]
         take_frame = config.get('take_frame', 1)
 
+        detection_frame = mp.Value('d', 0.0)
+
         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 = CameraCapture(name, ffmpeg_process, frame_shape, frame_queue, take_frame, camera_fps, detection_frame)
         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),
+            'process_fps': mp.Value('d', 0.0),
             'detection_fps': mp.Value('d', 0.0),
-            'detection_frame': mp.Value('d', 0.0),
+            'detection_frame': detection_frame,
             'read_start': mp.Value('d', 0.0),
             'ffmpeg_process': ffmpeg_process,
             'ffmpeg_cmd': ffmpeg_cmd,
@@ -216,8 +216,8 @@ def main():
         }
 
         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'], 
+            tflite_process.detection_queue, tracked_objects_queue, camera_processes[name]['process_fps'], 
+            camera_processes[name]['detection_fps'], 
             camera_processes[name]['read_start'], camera_processes[name]['detection_frame']))
         camera_process.daemon = True
         camera_processes[name]['process'] = camera_process
@@ -267,15 +267,17 @@ def main():
 
         for name, camera_stats in camera_processes.items():
             total_detection_fps += camera_stats['detection_fps'].value
+            capture_thread = camera_stats['capture_thread']
             stats[name] = {
-                'fps': round(camera_stats['fps'].value, 2),
-                'skipped_fps': round(camera_stats['skipped_fps'].value, 2),
+                'camera_fps': round(capture_thread.fps.eps(), 2),
+                'process_fps': round(camera_stats['process_fps'].value, 2),
+                'skipped_fps': round(capture_thread.skipped_fps.eps(), 2),
                 '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_process'].pid,
                 'frame_info': {
-                    'read': camera_stats['capture_thread'].current_frame,
+                    'read': capture_thread.current_frame,
                     'detect': camera_stats['detection_frame'].value,
                     'process': object_processor.camera_data[name]['current_frame_time']
                 }

frigate/video.py

@@ -115,7 +115,7 @@ def start_or_restart_ffmpeg(ffmpeg_cmd, frame_size, ffmpeg_process=None):
     return process
 
 class CameraCapture(threading.Thread):
-    def __init__(self, name, ffmpeg_process, frame_shape, frame_queue, take_frame, fps):
+    def __init__(self, name, ffmpeg_process, frame_shape, frame_queue, take_frame, fps, detection_frame):
         threading.Thread.__init__(self)
         self.name = name
         self.frame_shape = frame_shape
@@ -123,12 +123,16 @@ class CameraCapture(threading.Thread):
         self.frame_queue = frame_queue
         self.take_frame = take_frame
         self.fps = fps
+        self.skipped_fps = EventsPerSecond()
         self.plasma_client = PlasmaManager()
         self.ffmpeg_process = ffmpeg_process
         self.current_frame = 0
+        self.last_frame = 0
+        self.detection_frame = detection_frame
 
     def run(self):
         frame_num = 0
+        self.skipped_fps.start()
         while True:
             if self.ffmpeg_process.poll() != None:
                 print(f"{self.name}: ffmpeg process is not running. exiting capture thread...")
@@ -141,8 +145,16 @@ class CameraCapture(threading.Thread):
                 print(f"{self.name}: ffmpeg didnt return a frame. something is wrong.")
                 continue
 
+            self.fps.update()
+
             frame_num += 1
             if (frame_num % self.take_frame) != 0:
+                self.skipped_fps.update()
+                continue
+
+            # if the detection process is more than 1 second behind, skip this frame
+            if self.detection_frame.value > 0.0 and (self.last_frame - self.detection_frame.value) > 1:
+                self.skipped_fps.update()
                 continue
 
             # put the frame in the plasma store
@@ -153,13 +165,14 @@ class CameraCapture(threading.Thread):
                 )
             # add to the queue
             self.frame_queue.put(self.current_frame)
+            self.last_frame = self.current_frame
 
-            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, detection_frame):
+def track_camera(name, config, global_objects_config, frame_queue, frame_shape, detection_queue, detected_objects_queue, fps, detection_fps, read_start, detection_frame):
     print(f"Starting process for {name}: {os.getpid()}")
     listen()
 
+    detection_frame.value = 0.0
+
     # Merge the tracked object config with the global config
     camera_objects_config = config.get('objects', {})    
     # combine tracked objects lists
@@ -172,8 +185,6 @@ def track_camera(name, config, global_objects_config, frame_queue, frame_shape,
     for obj in objects_with_config:
         object_filters[obj] = {**global_object_filters.get(obj, {}), **camera_object_filters.get(obj, {})}
 
-    expected_fps = config['fps']
-
     frame = np.zeros(frame_shape, np.uint8)
 
     # load in the mask for object detection
@@ -192,12 +203,9 @@ def track_camera(name, config, global_objects_config, frame_queue, frame_shape,
     object_tracker = ObjectTracker(10)
 
     plasma_client = PlasmaManager()
-    frame_num = 0
     avg_wait = 0.0
     fps_tracker = EventsPerSecond()
-    skipped_fps_tracker = EventsPerSecond()
     fps_tracker.start()
-    skipped_fps_tracker.start()
     object_detector.fps.start()
     while True:
         read_start.value = datetime.datetime.now().timestamp()
@@ -206,31 +214,20 @@ def track_camera(name, config, global_objects_config, frame_queue, frame_shape,
         read_start.value = 0.0
         avg_wait = (avg_wait*99+duration)/100
         detection_frame.value = frame_time
-
-        fps_tracker.update()
-        fps.value = fps_tracker.eps()
-        detection_fps.value = object_detector.fps.eps()
         
         # 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
+
+        fps_tracker.update()
+        fps.value = fps_tracker.eps()
+        detection_fps.value = object_detector.fps.eps()
         
         # look for motion
         motion_boxes = motion_detector.detect(frame)
 
-        # skip object detection if we are below the min_fps and wait time is less than half the average
-        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()
-
         tracked_objects = object_tracker.tracked_objects.values()
 
         # merge areas of motion that intersect with a known tracked object into a single area to look at