Fix previews failing when disabled (#16962)

* Fix previews failing when offline

* Simplify frame cache handling

frigate/output/output.py

@@ -41,22 +41,30 @@ def check_disabled_camera_update(
     has_enabled_camera = False
 
     for camera, last_update in write_times.items():
+        offline_time = now - last_update
+
         if config.cameras[camera].enabled:
             has_enabled_camera = True
+        else:
+            # flag camera as offline when it is disabled
+            previews[camera].flag_offline(now)
 
-        if now - last_update > 1:
+        if offline_time > 1:
-            # last camera update was more than one second ago
+            # last camera update was more than 1 second ago
-            # need to send empty data to updaters because current
+            # need to send empty data to birdseye because current
             # frame is now out of date
-            frame = get_blank_yuv_frame(
+            if birdseye and offline_time < 10:
-                config.cameras[camera].detect.width,
+                # we only need to send blank frames to birdseye at the beginning of a camera being offline
-                config.cameras[camera].detect.height,
+                birdseye.write_data(
-            )
+                    camera,
-
+                    [],
-            if birdseye:
+                    [],
-                birdseye.write_data(camera, [], [], now, frame)
+                    now,
-
+                    get_blank_yuv_frame(
-            previews[camera].write_data([], [], now, frame)
+                        config.cameras[camera].detect.width,
+                        config.cameras[camera].detect.height,
+                    ),
+                )
 
     if not has_enabled_camera and birdseye:
         birdseye.all_cameras_disabled()
@@ -170,6 +178,12 @@ def output_frames(
         else:
             failed_frame_requests[camera] = 0
 
+        # send frames for low fps recording
+        preview_recorders[camera].write_data(
+            current_tracked_objects, motion_boxes, frame_time, frame
+        )
+        preview_write_times[camera] = frame_time
+
         # send camera frame to ffmpeg process if websockets are connected
         if any(
             ws.environ["PATH_INFO"].endswith(camera) for ws in websocket_server.manager
@@ -193,11 +207,6 @@ def output_frames(
                 frame,
             )
 
-        # send frames for low fps recording
-        preview_recorders[camera].write_data(
-            current_tracked_objects, motion_boxes, frame_time, frame
-        )
-        preview_write_times[camera] = frame_time
         frame_manager.close(frame_name)
 
     move_preview_frames("clips")

frigate/output/preview.py

@@ -23,7 +23,7 @@ from frigate.ffmpeg_presets import (
 )
 from frigate.models import Previews
 from frigate.object_processing import TrackedObject
-from frigate.util.image import copy_yuv_to_position, get_yuv_crop
+from frigate.util.image import copy_yuv_to_position, get_blank_yuv_frame, get_yuv_crop
 
 logger = logging.getLogger(__name__)
 
@@ -153,6 +153,7 @@ class PreviewRecorder:
         self.config = config
         self.start_time = 0
         self.last_output_time = 0
+        self.offline = False
         self.output_frames = []
 
         if config.detect.width > config.detect.height:
@@ -241,6 +242,17 @@ class PreviewRecorder:
             self.last_output_time = ts
             self.output_frames.append(ts)
 
+    def reset_frame_cache(self, frame_time: float) -> None:
+        self.segment_end = (
+            (datetime.datetime.now() + datetime.timedelta(hours=1))
+            .astimezone(datetime.timezone.utc)
+            .replace(minute=0, second=0, microsecond=0)
+            .timestamp()
+        )
+        self.start_time = frame_time
+        self.last_output_time = frame_time
+        self.output_frames: list[float] = []
+
     def should_write_frame(
         self,
         current_tracked_objects: list[dict[str, any]],
@@ -307,7 +319,9 @@ class PreviewRecorder:
         motion_boxes: list[list[int]],
         frame_time: float,
         frame: np.ndarray,
-    ) -> bool:
+    ) -> None:
+        self.offline = False
+
         # check for updated record config
         _, updated_record_config = self.config_subscriber.check_for_update()
 
@@ -319,7 +333,7 @@ class PreviewRecorder:
             self.start_time = frame_time
             self.output_frames.append(frame_time)
             self.write_frame_to_cache(frame_time, frame)
-            return False
+            return
 
         # check if PREVIEW clip should be generated and cached frames reset
         if frame_time >= self.segment_end:
@@ -340,32 +354,35 @@ class PreviewRecorder:
                     f"Not saving preview for {self.config.name} because there are no saved frames."
                 )
 
-            # reset frame cache
+            self.reset_frame_cache(frame_time)
-            self.segment_end = (
-                (datetime.datetime.now() + datetime.timedelta(hours=1))
-                .astimezone(datetime.timezone.utc)
-                .replace(minute=0, second=0, microsecond=0)
-                .timestamp()
-            )
-            self.start_time = frame_time
-            self.last_output_time = frame_time
-            self.output_frames: list[float] = []
 
             # include first frame to ensure consistent duration
             if self.config.record.enabled:
                 self.output_frames.append(frame_time)
                 self.write_frame_to_cache(frame_time, frame)
 
-            return True
+            return
         elif self.should_write_frame(current_tracked_objects, motion_boxes, frame_time):
             self.output_frames.append(frame_time)
             self.write_frame_to_cache(frame_time, frame)
-            return False
+            return
 
     def flag_offline(self, frame_time: float) -> None:
+        if not self.offline:
+            self.write_frame_to_cache(
+                frame_time,
+                get_blank_yuv_frame(
+                    self.config.detect.width, self.config.detect.height
+                ),
+            )
+            self.offline = True
+
         # check if PREVIEW clip should be generated and cached frames reset
         if frame_time >= self.segment_end:
             if len(self.output_frames) == 0:
+                # camera has been offline for entire hour
+                # we have no preview to create
+                self.reset_frame_cache(frame_time)
                 return
 
             old_frame_path = get_cache_image_name(
@@ -382,16 +399,7 @@ class PreviewRecorder:
                 self.requestor,
             ).start()
 
-            # reset frame cache
+            self.reset_frame_cache(frame_time)
-            self.segment_end = (
-                (datetime.datetime.now() + datetime.timedelta(hours=1))
-                .astimezone(datetime.timezone.utc)
-                .replace(minute=0, second=0, microsecond=0)
-                .timestamp()
-            )
-            self.start_time = frame_time
-            self.last_output_time = frame_time
-            self.output_frames = []
 
     def stop(self) -> None:
         self.requestor.stop()