Improved corrupt frame handling

camdetect.py

@@ -376,12 +376,14 @@ async def download(resp, queue):
                 blob = buf + data[:marker+2]
 
                 # Parse DCT coefficients
+                try:
                     dct = loads(blob)
-
+                except RuntimeError:
+                    counter_frames.labels("corrupted").inc()
+                else:
                     now = datetime.utcnow()
                     gauge_last_frame.labels("download").set(now.timestamp())
                     try:
-                    # Convert Y component to 16 bit for easier handling
                         queue.put_nowait((
                             now,
                             blob,
@@ -395,7 +397,7 @@ async def download(resp, queue):
                 counter_receive_frames.inc()
 
         # seek begin
-        marker = data.find(b"\xff\xd8")
+        marker = data.rfind(b"\xff\xd8")
         if marker >= 0:
             buf = data[marker:]
         else: