tail last 100 lines of ffmpeg logs and dump when failure detected

frigate/log.py

@@ -7,6 +7,7 @@ import queue
 import multiprocessing as mp
 from logging import handlers
 from setproctitle import setproctitle
+from collections import deque
 
 
 def listener_configurer():
@@ -54,6 +55,7 @@ class LogPipe(threading.Thread):
         self.daemon = False
         self.logger = logging.getLogger(log_name)
         self.level = level
+        self.deque = deque(maxlen=100)
         self.fdRead, self.fdWrite = os.pipe()
         self.pipeReader = os.fdopen(self.fdRead)
         self.start()
@@ -67,9 +69,13 @@ class LogPipe(threading.Thread):
         """Run the thread, logging everything.
         """
         for line in iter(self.pipeReader.readline, ''):
-            self.logger.log(self.level, line.strip('\n'))
+            self.deque.append(line.strip('\n'))
 
         self.pipeReader.close()
+    
+    def dump(self):
+        while len(self.deque) > 0:
+            self.logger.log(self.level, self.deque.popleft())
 
     def close(self):
         """Close the write end of the pipe.

frigate/video.py

@@ -181,6 +181,7 @@ class CameraWatchdog(threading.Thread):
             now = datetime.datetime.now().timestamp()
 
             if not self.capture_thread.is_alive():
+                self.logpipe.dump()
                 self.start_ffmpeg_detect()
             elif now - self.capture_thread.current_frame.value > 20:
                 self.logger.info(f"No frames received from {self.camera_name} in 20 seconds. Exiting ffmpeg...")
@@ -197,6 +198,7 @@ class CameraWatchdog(threading.Thread):
                 poll = p['process'].poll()
                 if poll == None:
                     continue
+                p['logpipe'].dump()
                 p['process'] = start_or_restart_ffmpeg(p['cmd'], self.logger, p['logpipe'], ffmpeg_process=p['process'])
             
             # wait a bit before checking again