save clips for tracked objects

Dockerfile

@@ -24,6 +24,7 @@ RUN apt -qq update && apt -qq install --no-install-recommends -y \
         numpy \
         imutils \
         scipy \
+        psutil \
     && python3.7 -m pip install -U \
         Flask \
         paho-mqtt \
@@ -49,6 +50,8 @@ RUN wget -q https://dl.google.com/coral/canned_models/coco_labels.txt -O /labelm
 RUN wget -q https://github.com/google-coral/edgetpu/raw/master/test_data/ssd_mobilenet_v2_coco_quant_postprocess.tflite -O /cpu_model.tflite 
 
 
+RUN mkdir /cache && mkdir /clips
+
 WORKDIR /opt/frigate/
 ADD frigate frigate/
 COPY detect_objects.py .

config/config.example.yml

@@ -110,6 +110,15 @@ cameras:
     ################
     take_frame: 1
 
+    ################
+    # This will save a clip for each tracked object by frigate along with a json file that contains
+    # data related to the tracked object. This works by telling ffmpeg to write video segments to /cache
+    # from the video stream without re-encoding. Clips are them created by using ffmpeg to merge segments
+    # without re-encoding. The segements saved are unaltered from what frigate receives to avoid re-encoding.
+    # They do not contain bounding boxes. 30 seconds of video is added to the start of the clip.
+    ################
+    save_clips: False
+
     ################
     # Configuration for the snapshots in the debug view and mqtt
     ################

detect_objects.py

@@ -17,6 +17,7 @@ import paho.mqtt.client as mqtt
 
 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.events import EventProcessor
 from frigate.util import EventsPerSecond
 from frigate.edgetpu import EdgeTPUProcess
 
@@ -176,6 +177,9 @@ def main():
 
     # Queue for cameras to push tracked objects to
     tracked_objects_queue = mp.SimpleQueue()
+
+    # Queue for clip processing
+    event_queue = mp.Queue()
     
     # Start the shared tflite process
     tflite_process = EdgeTPUProcess()
@@ -190,6 +194,25 @@ def main():
         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'])
+        if config.get('save_clips', False):
+            ffmpeg_output_args = [
+                "-f",
+                "segment",
+                "-segment_time",
+                "10",
+                "-segment_format",
+                "mp4",
+                "-reset_timestamps",
+                "1",
+                "-strftime",
+                "1",
+                "-c",
+                "copy",
+                "-an",
+                "-map",
+                "0",
+                f"/cache/{name}-%Y%m%d%H%M%S.mp4"
+            ] + ffmpeg_output_args
         ffmpeg_cmd = (['ffmpeg'] +
                 ffmpeg_global_args +
                 ffmpeg_hwaccel_args +
@@ -239,8 +262,11 @@ def main():
     for name, camera_process in camera_processes.items():
         camera_process['process'].start()
         print(f"Camera_process started for {name}: {camera_process['process'].pid}")
-    
-    object_processor = TrackedObjectProcessor(CONFIG['cameras'], client, MQTT_TOPIC_PREFIX, tracked_objects_queue)
+
+    event_processor = EventProcessor(CONFIG['cameras'], camera_processes, '/cache', '/clips', event_queue)
+    event_processor.start()
+
+    object_processor = TrackedObjectProcessor(CONFIG['cameras'], client, MQTT_TOPIC_PREFIX, tracked_objects_queue, event_queue)
     object_processor.start()
     
     camera_watchdog = CameraWatchdog(camera_processes, CONFIG['cameras'], tflite_process, tracked_objects_queue, plasma_process)

frigate/events.py

@@ -0,0 +1,152 @@
+import os
+import time
+import psutil
+import threading
+from collections import defaultdict
+import json
+import datetime
+import subprocess as sp
+import queue
+
+class EventProcessor(threading.Thread):
+    def __init__(self, config, camera_processes, cache_dir, clip_dir, event_queue):
+        threading.Thread.__init__(self)
+        self.config = config
+        self.camera_processes = camera_processes
+        self.cache_dir = cache_dir
+        self.clip_dir = clip_dir
+        self.cached_clips = {}
+        self.event_queue = event_queue
+        self.events_in_process = {}
+    
+    def refresh_cache(self):
+        cached_files = os.listdir(self.cache_dir)
+
+        files_in_use = []
+        for process_data in self.camera_processes.values():
+            try:
+                ffmpeg_process = psutil.Process(pid=process_data['ffmpeg_process'].pid)
+                flist = ffmpeg_process.open_files()
+                if flist:
+                    for nt in flist:
+                        if nt.path.startswith(self.cache_dir):
+                            files_in_use.append(nt.path.split('/')[-1])
+            except:
+                continue
+
+        for f in cached_files:
+            if f in files_in_use or f in self.cached_clips:
+                continue
+
+            camera = f.split('-')[0]
+            start_time = datetime.datetime.strptime(f.split('-')[1].split('.')[0], '%Y%m%d%H%M%S')
+        
+            ffprobe_cmd = " ".join([
+                'ffprobe',
+                '-v',
+                'error',
+                '-show_entries',
+                'format=duration',
+                '-of',
+                'default=noprint_wrappers=1:nokey=1',
+                f"{os.path.join(self.cache_dir,f)}"
+            ])
+            p = sp.Popen(ffprobe_cmd, stdout=sp.PIPE, shell=True)
+            (output, err) = p.communicate()
+            p_status = p.wait()
+            if p_status == 0:
+                duration = float(output.decode('utf-8').strip())
+            else:
+                print(f"bad file: {f}")
+                os.remove(os.path.join(self.cache_dir,f))
+                continue
+
+            self.cached_clips[f] = {
+                'path': f,
+                'camera': camera,
+                'start_time': start_time.timestamp(),
+                'duration': duration
+            }
+
+        if len(self.events_in_process) > 0:
+            earliest_event = min(self.events_in_process.values(), key=lambda x:x['start_time'])['start_time']
+        else:
+            earliest_event = datetime.datetime.now().timestamp()
+        
+        for f, data in list(self.cached_clips.items()):
+            if earliest_event-90 > data['start_time']+data['duration']:
+                del self.cached_clips[f]
+                os.remove(os.path.join(self.cache_dir,f))
+
+    def create_clip(self, camera, event_data):
+        # get all clips from the camera with the event sorted
+        sorted_clips = sorted([c for c in self.cached_clips.values() if c['camera'] == camera], key = lambda i: i['start_time'])
+
+        while sorted_clips[-1]['start_time'] + sorted_clips[-1]['duration'] < event_data['end_time']:
+            time.sleep(5)
+            self.refresh_cache()
+            # get all clips from the camera with the event sorted
+            sorted_clips = sorted([c for c in self.cached_clips.values() if c['camera'] == camera], key = lambda i: i['start_time'])
+        
+        playlist_start = event_data['start_time']-30
+        playlist_end = event_data['end_time']+5
+        playlist_lines = []
+        for clip in sorted_clips:
+            # clip ends before playlist start time, skip
+            if clip['start_time']+clip['duration'] < playlist_start:
+                continue
+            # clip starts after playlist ends, finish
+            if clip['start_time'] > playlist_end:
+                break
+            playlist_lines.append(f"file '{os.path.join(self.cache_dir,clip['path'])}'")
+            # if this is the starting clip, add an inpoint
+            if clip['start_time'] < playlist_start:
+                playlist_lines.append(f"inpoint {int(playlist_start-clip['start_time'])}")
+            # if this is the ending clip, add an outpoint
+            if clip['start_time']+clip['duration'] > playlist_end:
+                playlist_lines.append(f"outpoint {int(playlist_end-clip['start_time'])}")
+
+        clip_name = f"{camera}-{event_data['id']}"
+        ffmpeg_cmd = [
+            'ffmpeg',
+            '-y',
+            '-protocol_whitelist',
+            'pipe,file',
+            '-f',
+            'concat',
+            '-safe',
+            '0',
+            '-i',
+            '-',
+            '-c',
+            'copy',
+            f"{os.path.join(self.clip_dir, clip_name)}.mp4"
+        ]
+
+        p = sp.run(ffmpeg_cmd, input="\n".join(playlist_lines), encoding='ascii', capture_output=True)
+        if p.returncode != 0:
+            print(p.stderr)
+            return
+        
+        with open(f"{os.path.join(self.clip_dir, clip_name)}.json", 'w') as outfile:
+            json.dump(event_data, outfile)
+
+    def run(self):
+        while True:
+            try:
+                event_type, camera, event_data = self.event_queue.get(timeout=10)
+            except queue.Empty:
+                self.refresh_cache()
+                continue
+
+            self.refresh_cache()
+
+            if event_type == 'start':
+                self.events_in_process[event_data['id']] = event_data
+
+            if event_type == 'end':
+                if self.config[camera].get('save_clips', False) and len(self.cached_clips) > 0:
+                    self.create_clip(camera, event_data)
+                del self.events_in_process[event_data['id']]
+
+                

frigate/object_processing.py

@@ -23,12 +23,13 @@ for key, val in LABELS.items():
     COLOR_MAP[val] = tuple(int(round(255 * c)) for c in cmap(key)[:3])
 
 class TrackedObjectProcessor(threading.Thread):
-    def __init__(self, config, client, topic_prefix, tracked_objects_queue):
+    def __init__(self, config, client, topic_prefix, tracked_objects_queue, event_queue):
         threading.Thread.__init__(self)
         self.config = config
         self.client = client
         self.topic_prefix = topic_prefix
         self.tracked_objects_queue = tracked_objects_queue
+        self.event_queue = event_queue
         self.camera_data = defaultdict(lambda: {
             'best_objects': {},
             'object_status': defaultdict(lambda: defaultdict(lambda: 'OFF')),
@@ -50,12 +51,35 @@ class TrackedObjectProcessor(threading.Thread):
 
     def run(self):
         while True:
-            camera, frame_time, tracked_objects = self.tracked_objects_queue.get()
+            camera, frame_time, current_tracked_objects = self.tracked_objects_queue.get()
 
             config = self.config[camera]
             best_objects = self.camera_data[camera]['best_objects']
             current_object_status = self.camera_data[camera]['object_status']
-            self.camera_data[camera]['tracked_objects'] = tracked_objects
+            tracked_objects = self.camera_data[camera]['tracked_objects']
+
+            current_ids = current_tracked_objects.keys()
+            previous_ids = tracked_objects.keys()
+            removed_ids = list(set(previous_ids).difference(current_ids))
+            new_ids = list(set(current_ids).difference(previous_ids))
+            updated_ids = list(set(current_ids).intersection(previous_ids))
+
+            for id in new_ids:
+                tracked_objects[id] = current_tracked_objects[id]
+                # publish events to mqtt
+                self.client.publish(f"{self.topic_prefix}/{camera}/events/start", json.dumps(tracked_objects[id]), retain=False)
+                self.event_queue.put(('start', camera, tracked_objects[id]))
+            
+            for id in updated_ids:
+                tracked_objects[id] = current_tracked_objects[id]
+            
+            for id in removed_ids:
+                # publish events to mqtt
+                tracked_objects[id]['end_time'] = frame_time
+                self.client.publish(f"{self.topic_prefix}/{camera}/events/end", json.dumps(tracked_objects[id]), retain=False)
+                self.event_queue.put(('end', camera, tracked_objects[id]))
+                del tracked_objects[id]
+
             self.camera_data[camera]['current_frame_time'] = frame_time
 
             ###

frigate/objects.py

@@ -19,6 +19,7 @@ class ObjectTracker():
     def register(self, index, obj):
         id = f"{obj['frame_time']}-{index}"
         obj['id'] = id
+        obj['start_time'] = obj['frame_time']
         obj['top_score'] = obj['score']
         self.add_history(obj)
         self.tracked_objects[id] = obj
@@ -45,6 +46,9 @@ class ObjectTracker():
         }
         if 'history' in obj:
             obj['history'].append(entry)
+            # only maintain the last 20 in history
+            if len(obj['history']) > 20:
+                obj['history'] = obj['history'][-20:]
         else:
             obj['history'] = [entry]