Hi,
Please add nvvidconv plugin and try again:
gst-launch-1.0 v4l2src device=/dev/video0 io-mode=2 num-buffers=4 ! image/jpeg, width=640, height=480, format=MJPG ! nvjpegdec ! video/x-raw ! nvvidconv ! 'video/x-raw(memory:NVMM),format=I420' ! nvegltransform ! nveglglessink
And can try nvv4l2decoder:
gst-launch-1.0 v4l2src device=/dev/video0 io-mode=2 num-buffers=4 ! image/jpeg, width=640, height=480, format=MJPG ! jpegparse ! nvv4l2decoder mjpeg=1 ! nvegltransform ! nveglglessink