Unexpected frame drops using valve

Application Development
1

Hi, I have the following pipeline

v4l2src device=/dev/video3 !
videoconvert !
videoscale !
video/x-raw,width=640,height=480,format=BGRx !
valve !
tee name=tee0 !
  queue leaky=downstream max-size-buffers=1 max-size-bytes=0 max-size-time=0 !
  custom_element ! 
  fakesink
tee0. !
  queue !
  videoconvert !
  vpuenc_h264 !
  h264parse !
  mp4mux !
  filesink location=path/to/video.mp4

I want to record videos with the input frame-rate. The custom element is “too slow”, so I added the leaky queue. Without the valve element, a video is recorded as expected capturing all frames.

If I use the drop property of the valve element to (de)activate the pipeline dynamically, suddenly the videos show frame drops.