Currently testing the following stream to local Janus:

gst-launch-1.0 rpicamsrc preview=false ! video/x-raw,width=1024,height=768 ! x264enc speed-preset=ultrafast
tune=zerolatency byte-stream=true bitrate=5000 threads=1 ! h264parse config-interval=1 ! rtph264pay ! 
udpsink host=127.0.0.1 port=8004

This one is nice

gst-launch-1.0 rpicamsrc preview=false vflip=true ! x264enc tune=zerolatency speed-preset=ultrafast
qp-min=18  pass=5 quantizer=21 ! video/x-h264,width=640,height=480,framerate=30/1 ! rtph264pay ! udpsink
host=127.0.0.1 port=8004 sync=false

And with synced audio:

gst-launch-1.0 pulsesrc ! queue ! opusenc ! rtpopuspay ! udpsink host=127.0.0.1 port=8003 rpicamsrc
preview=false vflip=true ! x264enc tune=zerolatency speed-preset=ultrafast qp-min=18 pass=5 quantizer=21 !
video/x-h264,width=640,height=480,framerate=30/1 ! rtph264pay ! udpsink host=127.0.0.1 port=8004 sync=false

Using JANUS Gateway's streaming plugin configured as such:

[h264-sample]
type = rtp
id = 10
description = H.264 live stream coming from gstreamer
audio = yes
video = yes
videoport = 8004
audioport = 8003
audiopt = 111
audiortpmap = opus/48000/2
videopt = 126
videortpmap = H264/90000
videofmtp = profile-level-id=42e01f\;packetization-mode=1

Sources

• https://groups.google.com/forum/#!topic/meetecho-janus/k2_oz0Kptdw
• https://groups.google.com/forum/#!topic/meetecho-janus/KyEuS9I9B50
• https://www.rs-online.com/designspark/building-a-raspberry-pi-2-webrtc-camera
• https://raspberrypi.stackexchange.com/questions/26675/modern-way-to-stream-h-264-from-the-raspberry-cam