Try Raspberry Pi Zero W as GS with Release 23.01 image - fpv_video failed

[lida2003]

@svpcom

Hi, I got an idea about using Raspberry Pi Zero W as GS (using it's GPU I hope), so my configuration is as follows:

Raspberry Pi 3B+ (AirUnit) ==> Raspberry Pi Zero W(GS)

All seems fine, except no video output on HDMI screen.

Method 1

pi@raspberrypi:~ $ sudo systemctl start wifibroadcast@gs
pi@raspberrypi:~ $ sudo systemctl start fpv-video

.... ....
pi@raspberrypi:~ $ sudo systemctl status wifibroadcast@gs
● [email protected] - WFB profile gs
     Loaded: loaded (/lib/systemd/system/[email protected]; disabled; vendor preset: enabled)
     Active: active (running) since Tue 2023-03-14 01:37:57 GMT; 14min ago
   Main PID: 768 (wfb-server)
      Tasks: 6 (limit: 724)
        CPU: 3min 19.882s
     CGroup: /system.slice/system-wifibroadcast.slice/[email protected]
             ├─768 /usr/bin/python3 /usr/bin/wfb-server gs wfb-rf1
             ├─781 /usr/bin/wfb_rx -p 16 -u 14600 -K /etc/gs.key -i 7669206 wfb-rf1
             ├─782 /usr/bin/wfb_tx -p 144 -u 14601 -K /etc/gs.key -B 20 -G long -S 1 -L 1 -M 1 -k 1 -n 2 -T 0 -i 7669206 wfb-rf1
             ├─783 /usr/bin/wfb_rx -p 0 -c 127.0.0.1 -u 5600 -K /etc/gs.key -i 7669206 wfb-rf1
             ├─790 /usr/bin/wfb_rx -p 160 -u 14800 -K /etc/gs.key -i 7669206 wfb-rf1
             └─791 /usr/bin/wfb_tx -p 32 -u 14801 -K /etc/gs.key -B 20 -G long -S 1 -L 1 -M 1 -k 1 -n 2 -T 0 -i 7669206 wfb-rf1

Mar 14 01:38:18 raspberrypi wfb-server[768]: [server.init_tunnel #info] Tunnel RX: /usr/bin/wfb_rx -p 160 -u 14800 -K /etc/gs.key -i 7669206 wfb-rf1
Mar 14 01:38:18 raspberrypi wfb-server[768]: [server.init_tunnel #info] Tunnel TX: /usr/bin/wfb_tx -p 32 -u 14801 -K /etc/gs.key -B 20 -G long -S 1 -L 1 -M 1 -k 1 -n 2>
Mar 14 01:38:18 raspberrypi wfb-server[768]: [tcp.Port.startListening #info] AntennaFactory starting on 8003
Mar 14 01:38:18 raspberrypi wfb-server[768]: [server.RXProtocol.connectionMade #info] Started tunnel rx
Mar 14 01:38:18 raspberrypi wfb-server[768]: [server.TXProtocol.connectionMade #info] Started tunnel tx
Mar 14 01:38:18 raspberrypi wfb-server[768]: [server.DbgProtocol.lineReceived #info] telem tx: Listen on 14601 for wfb-rf1
Mar 14 01:38:18 raspberrypi wfb-server[768]: [server.DbgProtocol.lineReceived #info] tunnel tx: Listen on 14801 for wfb-rf1
Mar 14 01:38:56 raspberrypi wfb-server[768]: [server.AntennaProtocol.lineReceived #info] New session detected [tunnel rx]: FEC=VDM_RS K=1, N=2, epoch=0
Mar 14 01:39:23 raspberrypi wfb-server[768]: [server.AntennaProtocol.lineReceived #info] New session detected [video rx]: FEC=VDM_RS K=8, N=12, epoch=0
Mar 14 01:42:06 raspberrypi wfb-server[768]: [server.DbgProtocol.lineReceived #info] video rx: 256 packets lost

pi@raspberrypi:~ $ sudo systemctl status fpv-video
● fpv-video.service - FPV video
     Loaded: loaded (/etc/systemd/system/fpv-video.service; disabled; vendor preset: enabled)
     Active: activating (auto-restart) since Tue 2023-03-14 01:41:10 GMT; 1s ago
    Process: 1026 ExecStart=/bin/sh -c gst-launch-1.0 rtspsrc latency=0 location=rtsp://127.0.0.1:8554/wfb ! rtph264depay ! 'video/x-h264,s>
   Main PID: 1026 (code=exited, status=0/SUCCESS)
        CPU: 997ms

Mar 14 01:41:12 raspberrypi systemd[1]: fpv-video.service: Scheduled restart job, restart counter is at 16.
Mar 14 01:41:12 raspberrypi systemd[1]: Stopped FPV video.

Method 2

pi@raspberrypi:~ $ gst-launch-1.0 udpsrc port=5600 caps='application/x-rtp, media=(string)video, clock-rate=(int)90000, encoding-name=(string)H264' \
               ! rtph264depay ! avdec_h264 ! clockoverlay valignment=bottom ! autovideosink fps-update-interval=1000 sync=false
WARNING: erroneous pipeline: no element "avdec_h264"

---

[lida2003]

It seems OK now :)

Mate desktop + 720P @ 60FPS , excellent software, @svpcom !

[svpcom]

For example you can see video on RPI hdmi output and in QGC on the laptop simulteneously

[lida2003]

For example you can see video on RPI hdmi output and in QGC on the laptop simulteneously

OK, I got it. How about the latency when using RTP --> RTSP --> FPV_video, instead of RTP --> FPV_video?

[lida2003]

sudo systemctl start rtsp

Thanks, I got the code test-video.diff.zip, which is much more clear of the steaming path.

[svpcom]

RTSP is just signalling protocol. All data are transferred via RTP as before, but now RTP streams are dynamically configured by RTSP server. So latency via RTSP is the same as via RTP

[svpcom]

Yes, I leave patched gst rstp server sources for reference.