When I play mjpeg stream from camera fps is 8.34, no dropped frames and stays at that value no matter what I do. If I launch ten such streams in parallel fps decreases bit to 7-8, so this looks unrelated to performance.
Edit: I found out by setting camera fps to 5 that result has fps 1.66 and initial fps was 25. Both actual fps are 1/3 of original so it looks that it displays only each third frame.
Following pipeline shows what properties I tried, as well as trying to add queues, situation is same when I remove those.
START='souphttpsrc is-live=true keep-alive=true do_timestamp=true location="http://'$IP2'/axis-cgi/mjpg/video.cgi?resolution='$RX'x'$RY'&compression=30&fps='$FPS'" ! queue ! multipartdemux ! queue !'
gst-launch-1.0 $START vpudec ! queue ! fpsdisplaysink video-sink="glimagesink sync=false latency=500"