Video stream lost and video lag in custom software on herelink

I am trying to build a custom ground control software to deploy on herelink controller. I am able to establish telemetry communication using udp and also am able to get the video using the restream url rtsp://localhost:8554/fpv_stream.
But I notice that the stream is lags a lot and also many a times, the stream is lost.
I am building the application using Qt and Opencv for video. May be for lag in video I can do some code optimization and solve it but what can be the possible reason for video stream loss. I also tried rtsp:// url for streaming but the same result.
However on trying some other url like rtsp://, there is still some lag but no stream loss.
The pre installed QGC has something called “Auto connection video stream” which I am not able to decipher. What is this stream and what other approach can I take

This sounds like you’re attempting to co-mingle some of the pre-built -vs- what is possible.

Do you want to build a GCS from scratch or are you trying to do some integration with QGC?

I am building a GCS from scratch. Not a fork of QGC. But in the QGC application under General > Video > Stream, the stream name is Auto connect video stream. I want to know what that stream is because the restream url provided always keeps getting lost.

GCS from scratch. Now that sounds fun. It also sounds painful and bumpy and many years in the making.

Rather than starting with video I would ask if you’ve considered how you plan on interacting with the hardware. If you’ve already solved the hardware problem, cool. If not, concentrate on that first.

Video wise… Well, I’d leverage a v1.1 and use the Ethernet port on the air unit. Under stock conditions you will be limited to a Anything other than that subnet results in needing to have a copilot device as it were.

On the other hand perhaps you’ve not gone the Ethernet route and are yet leveraging the 2 built-in HDMI ports. If so I would think github a better place to ask such questions.


@stryngs, I have resolved the data communication as well as the video part. GCS is ready and works properly when run on windows using other hardware configurations. I have ported the application to android for use on herelink. In this case also I am able to get data and send data i.e. I am able to control the air vehicle. I am also getting video feed using the above mentioned urls.

My only problem is that the video is lost every now and then. But this does not happen in the case of QGC or solex. I want to know what url they use and if not a url then what is their source for video.
Also I am not aware of the Ethernet route. If there is any link please provide here, I will go through it.

For the ethernet you need version 1.1. A thread detailing the setup is here:
Ethernet on the Herelink 1.1 - #5 by stryngs.

When you say the video is lost, which and what is your current method for seeing video while not using QGC or Solex. i.e. Where are you telling the GCS app you built to listen?