Try Raspberry Pi Zero W as AirUnit + Raspberry Pi 3B+ as GS -- GS CPU 100%, GPS not used.

[lida2003]

I tried Raspberry Pi Zero W (AirUnit) ==> Raspberry Pi 3B+ (GS) with 1280 x 720 @ 30FPS. (with Release 23.01 image)

It seems that Raspberry Pi 3B+ (GS) didn't use GPU for H264 decoding, any thing wrong with gst-launch commands on gs?

gs command:

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 sync=false

[svpcom]

This pipeline is for drone (camera capture), not for GS

[svpcom]

For gs see /etc/systemd/system/fpv-video.service

[lida2003]

Sorry, I fixed type error.

[lida2003]

I hope that the h264 hardware decoder can do the decoding work instead of relying on the CPU.

[svpcom]

For RPI3 /etc/systemd/system/fpv-video.service use hw h264 decoder.
For x86 sw decoder is used

[lida2003]

OK.

I got an question here. my steps as follows:

1. sudo systemctl start wifibroadcast@gs
2. sudo systemctl start wifibroadcast@drone
3. sudo systemctl start fpv-video
4. drone gst-launch-1.0 720P@45FPS // OK, I got stable video
5. drone gst-launch-1.0 720P@30FPS // OK, I got stable video
6. drone gst-launch-1.0 720P@45FPS // OK, I got stable video
7. drone gst-launch-1.0 800x600@60FPS // video is gone, just desktop
8. drone gst-launch-1.0 720P@30FPS // still no video, desktop only
9. sudo systemctl stop fpv-video
10. sudo systemctl start fpv-video // video is back

It seems that I have to stop/start fpv-video when resolution changes.

[svpcom]

as I remember (may be wrong) some pi cameras supports only 49fps @720p

[lida2003]

If I didn't change the resolution, then it's OK.
e.g.
720p@30
720P@45
720p@60

if i change from 720P@45 to 800x600@30FPS, the video will stop. (Then I need to stop/start fpv video)