get two videos from udp src and stream it combined using videomixer and send it using udpsink

videomixer

gst-launch-1.0 \
    videomixer name=m sink_1::xpos=10 sink_1::ypos=10 sink_2::xpos=170 sink_2::ypos=10  \
    ! x264enc \
    ! rtph264pay \
    ! udpsink host=localhost port=5000 \
    videotestsrc pattern=white \
    ! video/x-raw, format=I420, framerate=5/1, width=330, height=170 \
    ! m. \
    udpsrc port=10001 caps = "application/x-rtp, media=(string)video, clock-rate=(int)90000, encoding-name=(string)H264, payload=(int)96" \
    ! rtph264depay \
    ! decodebin \
    ! videoconvert \
    ! videoscale \
    ! video/x-raw,width=150,height=150 \
    ! queue \
    ! m. \
    udpsrc port=10003 caps = "application/x-rtp, media=(string)video, clock-rate=(int)90000, encoding-name=(string)H264, payload=(int)96" \
    ! rtph264depay \
    ! decodebin \
    ! videoconvert \
    ! videoscale \
    ! video/x-raw,width=150,height=150 \
    ! queue \
    ! m.