safer

reproject/webrtc_server.py

@@ -93,6 +93,7 @@ class WebRTCServer:
         self.pcs = set()
         self.fps = fps
         self.frameContainer = [None]
+        self.frame_lock = threading.Lock()
         self.hub = MonitoringHub()
         self.sio = None
 
@@ -161,7 +162,7 @@ class WebRTCServer:
         await pc.setRemoteDescription(
             RTCSessionDescription(offer["sdp"], offer.get("type", "offer"))
         )
-        pc.addTrack(VideoFrameTrack(self.fps, self.frameContainer))
+        pc.addTrack(VideoFrameTrack(self.fps, self.frameContainer, self.frame_lock))
 
         dc = pc.createDataChannel("monitoring")
 
@@ -179,10 +180,12 @@ class WebRTCServer:
         asyncio.run_coroutine_threadsafe(self._websocket_start(), self.background_loop)
 
     def provide_frame(self, frame):
-        self.frameContainer[0] = frame
+        with self.frame_lock:
+            self.frameContainer[0] = frame.copy()
 
     def send_data(self, data):
-        self.hub.send_data(data)
+        if self.background_loop.is_running():
+            self.background_loop.call_soon_threadsafe(self.hub.send_data, data)
 
     def alert(self, timestamp, summary, level):
         payload = {
@@ -207,10 +210,11 @@ class WebRTCServer:
 
 
 class VideoFrameTrack(VideoStreamTrack):
-    def __init__(self, fps, fc):
+    def __init__(self, fps, fc, lock):
         super().__init__()
         self.fps = fps
         self.frameContainer = fc
+        self.frame_lock = lock
 
     async def next_timestamp(self):
         """
@@ -230,11 +234,13 @@ class VideoFrameTrack(VideoStreamTrack):
 
     async def recv(self):
         pts, time_base = await self.next_timestamp()
-        frame = self.frameContainer[0]
+        with self.frame_lock:
+            frame = self.frameContainer[0]
+            if frame is not None:
+                frame = frame.copy()
         if frame is None:
             frame = np.zeros((480, 640, 3), dtype=np.uint8)
         else:
-            frame = self.frameContainer[0]
             frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
         video_frame = av.VideoFrame.from_ndarray(frame, format="rgb24")
         video_frame.pts = pts
@@ -255,4 +261,4 @@ def route_channel(channel):
                 print(f"Latency: {now - pre}ms")
 
         case _:
-            print(f"Unknown Channel {channel.label}")
+            print(f"Unknown Channel {channel.label}")