Live Streaming from Crawler - Low Latency, LAN Only

Hello Craig,
I am trying Theta V with Rapi 4. The Theta V will be attached on a crawler robot and I am going to control and view over LAN with no internet environment.
Because of I failed to load Theta V on /dev/video0, I am going to approach this diagram. I have setup Janus on raspi but don’t know how to install RTSP Streaming Plugin and how to use Theta V from raspi yet.
I have tried for 2 weeks and still not success yet. I can run
gst-launch-1.0 thetauvcsrc mode=0 do-timestamp=true ! h264parse ! openh264dec ! videoconvert ! autovideosink

gst-launch-1.0 thetauvcsrc mode=0 do-timestamp=true ! h264parse ! avdec_h264 ! videoconvert ! autovideosink

but failed following because of not mounted on /dev/video0.

gst-launch-1.0 thetauvcsrc mode=0 do-timestamp=true ! h264parse ! v4l2h264dec ! videoconvert ! autovideosink

Sorry for long content and please let me post my info

pi@testenv:~ $ lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 004: ID 05ca:2712 Ricoh Co., Ltd RICOH THETA V
Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
pi@testenv:~ $ v4l2-ctl --list-devices
bcm2835-codec-decode (platform:bcm2835-codec):
        /dev/video10
        /dev/video11
        /dev/video12
        /dev/video18
        /dev/video31
        /dev/media3

bcm2835-isp (platform:bcm2835-isp):
        /dev/video13
        /dev/video14
        /dev/video15
        /dev/video16
        /dev/video20
        /dev/video21
        /dev/video22
        /dev/video23
        /dev/media1
        /dev/media2

rpivid (platform:rpivid):
        /dev/video19
        /dev/media0

Dummy video device (0x0000) (platform:v4l2loopback-000):
        /dev/video0

pi@testenv:~ $ sudo modprobe uvcvideo
pi@testenv:~ $ v4l2-ctl --list-devices
bcm2835-codec-decode (platform:bcm2835-codec):
        /dev/video10
        /dev/video11
        /dev/video12
        /dev/video18
        /dev/video31
        /dev/media3

bcm2835-isp (platform:bcm2835-isp):
        /dev/video13
        /dev/video14
        /dev/video15
        /dev/video16
        /dev/video20
        /dev/video21
        /dev/video22
        /dev/video23
        /dev/media1
        /dev/media2

rpivid (platform:rpivid):
        /dev/video19
        /dev/media0

Dummy video device (0x0000) (platform:v4l2loopback-000):
        /dev/video0

RICOH THETA V: RICOH THETA V (usb-0000:01:00.0-1.1):
        /dev/media4

pi@testenv:~ $ v4l2-ctl --info
Driver Info:
        Driver name      : v4l2 loopback
        Card type        : Dummy video device (0x0000)
        Bus info         : platform:v4l2loopback-000
        Driver version   : 6.6.51
        Capabilities     : 0x85200003
                Video Capture
                Video Output
                Read/Write
                Streaming
                Extended Pix Format
                Device Capabilities
        Device Caps      : 0x05200003
                Video Capture
                Video Output
                Read/Write
                Streaming
                Extended Pix Format
pi@testenv:~ $ v4l2-ctl --list-formats-ext
ioctl: VIDIOC_ENUM_FMT
        Type: Video Capture