can't decrypt error

[QiXuanWang]

I was able to start the process but somehow RX reported error as: ... 379062 PKT 0:0:0:0:0:0 380063 PKT 0:0:0:0:0:0 381064 PKT 0:0:0:0:0:0 382065 PKT 0:0:0:0:0:0 unable to decrypt packet #0xd801 unable to decrypt packet #0xd802 unable to decrypt packet #0xd803 unable to decrypt packet #0xd804 unable to decrypt packet #0xd805 unable to decrypt packet #0xd806 383065 PKT 6:6:0:0:0:0 384067 PKT 0:0:0:0:0:0 385068 PKT 0:0:0:0:0:0 386069 PKT 0:0:0:0:0:0 387070 PKT 0:0:0:0:0:0 unable to decrypt packet #0x1c30a unable to decrypt packet #0x1c30b unable to decrypt packet #0x1c400 unable to decrypt packet #0x1c401 unable to decrypt packet #0x1c402 unable to decrypt packet #0x1c403 unable to decrypt packet #0x1c404 388070 PKT 7:7:0:0:0:0 389071 PKT 0:0:0:0:0:0 390073 PKT 0:0:0:0:0:0 391074 PKT 0:0:0:0:0:0 392075 PKT 0:0:0:0:0:0 393076 PKT 0:0:0:0:0:0 394077 PKT 0:0:0:0:0:0 395078 PKT 0:0:0:0:0:0 396079 PKT 0:0:0:0:0:0 ... I'm using the both keys generated on TX (copied gs.key from TX to RX) So how can I debug for next step?

[svpcom]

Check that gs.key and drone.key was generated in the same run of wfb_keygen program. Small amount of decrypt error after startup can be normal because encrypted session key is announced with 1s period and while RX doesn't get an encrypted session key it unable to decrypt packet stream. See https://github.com/svpcom/wifibroadcast/wiki/Encryption

[QiXuanWang]

Thanks. I,m no expert on this. Now I'm trying to use VLC to view the RTP/UDP stream? I tried on both TX and RX with rtp://@:5600 but failed. I'm not running advanced setup for telemetry yet. I followed the PX4+WifiBroadcast instructions.

[svpcom]

PX4 + WFB instruction is quite old. I've filled a pull request https://github.com/PX4/Devguide/pull/723 , but it not still applied. Use gstreamer or QGroundControl instead of vlc. VLC is unable to show raw RTP stream without dirty hacks.

[QiXuanWang]

Thanks. Just to update what I had now by following instructions of PX4 version. It worked, with extremely slow video. Actually, it's static indeed. I don;t know if it's RPI3 setting problem or WFB software problem. But it won't work compared with EZWifibroadcast. The gst-launch did open up a video window but the content never changed...

I'll try to follow the advanced setup guide you posted (https://github.com/svpcom/wifibroadcast/wiki/Setup-HOWTO) and see if I can get better results.

There are several points I don't really understand about that guide after reading it over and over again :) But one particular thing is, mavlink_router should only be used on TX right? With this guide, Can I still use "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" to decode on RX?

[svpcom]

Yes, mavlink_router is needed only if you want to transmit teletemtry on the drone. If you want to use video only you don't need to configure it

[svpcom]

yes. You could use gstremer on the ground to decode video

[QiXuanWang]

It seems my problem is that RX can't receive data. Either it can't decrypt or it fails to receive at all. Have tried both 5G and 2G but no difference. There must be some steps that I missed. I'll try the trouble-shooting solution. A few more questions:

1. For telemetry, can I use port=5600 and 14550 for both TX and RX, for wifibroadcast.cfg?
2. When I run ./script/tx_standalone,sh wlan1, will wifibroadcast.cfg work? From what I can tell, it won't but just to confirm.
3. for TX, "raspivid --nopreview --awb auto -ih -t 0 -w 640 -h 480 -fps 30 -b 4000000 -g 30 -pf high -o - | gst-launch-1.0 fdsrc ! h264parse ! rtph264pay ! udpsink host=127.0.0.1 port=5600" Is the "4000000" correct or should I use "4000"?

[QiXuanWang]

This is some sample RX infor:

override block 0x701f with 0 fragments override block 0x7020 with 0 fragments override block 0x7021 with 0 fragments override block 0x7022 with 0 fragments override block 0x7023 with 0 fragments override block 0x7024 with 0 fragments override block 0x7025 with 0 fragments override block 0x7026 with 0 fragments override block 0x7027 with 0 fragments override block 0x7028 with 5 fragments 3600 packets lost 87223632 ANT 1 11:-22:-20:-20 87223632 ANT 0 11:-16:-14:-14 87223632 PKT 11:0:11:8:3600:0 87224633 PKT 0:0:0:0:0:0 87225634 PKT 0:0:0:0:0:0 87226635 PKT 0:0:0:0:0:0

Does it indicate failing to receive or failing to decrypt??

[svpcom]

1. Yes
2. No, wifibroadcast.cfg is only for python daemon. wfb_tx and wfb_rx utilities use only command-line parameters.
3. My config for Pi camera: gst-launch-1.0 rpicamsrc annotation-mode=0xc bitrate=4000000 keyframe-interval=49 inline-headers=true sensor-mode=5 drc=0 preview=false fullscreen=false iso=0 awb-mode=sunlight metering-mode=matrix ! video/x-h264,profile=high,width=1280,height=720,framerate=49/1,stream-format=byte-stream ! h264parse ! rtph264pay config-interval=1 pt=96 ! udpsink host=127.0.0.1 port=5600

Check you RPI CPU usage. It may be not enough cpu power for camera + wfb

[svpcom]

87223632 ANT 1 11:-22:-20:-20
87223632 ANT 0 11:-16:-14:-14
87223632 PKT 11:0:11:8:3600:0

this mean than antenna 0 got 11 packets with average RSSI -14dB PKT fileds: count_p_all, count_p_dec_err, count_p_dec_ok, count_p_fec_recovered, count_p_lost, count_p_bad total 11, 0 bad, 11 decrypt success, 8 recovered via FEC (because some packets was lost)

[QiXuanWang]

The decrypt issue should be related to wificard power issue. Close until I have further findings.