AP_Camera: add Python examples for GStreamer UDP and RTSP video streams

[srmainwaring]

Python examples demonstrating how to manipulate UDP and RTSP video streams using GStreamer.

The UDP to RTSP converter addresses the problem of consuming a simulated video stream from Gazebo in more than one application using standard installations of GStreamer and opencv (no need for a custom build and install of opencv).

Related:

• AP_Camera: Add Camera Tracking functionality (WIP) #27773
• AP_camera: Camera tracking example scripts (WIP) #27903
• https://github.com/ArduPilot/ardupilot_gazebo?tab=readme-ov-file#3-streaming-camera-video

[rmackay9]

Another possible place to put this would be in the Tools/camera_gimbals directory where I've put some download scripts https://github.com/ArduPilot/ardupilot/tree/master/Tools/cameras_gimbals

[srmainwaring]

@rmackay9 - the idea was to keep the scripts in AP_Camera/examples to complement the GSoC camera tracking examples in #27903.

The other thought was to move them into a MAVProxy module/example. I've started looking through the mavproxy_SIYI module, as it has many features that would be nice to have in a general camera / gimbal screen, but also is heavily customised to the SIYI and I'm not sure if the general purpose features can be factored out easily.

Regarding the opencv / gstreamer integration: I've found that a custom build of opencv-python is possible on macOS using brew if the formula for opencv is edited and the package is installed using a --build-from-source flag. I guess the questions is whether requiring a custom build of opencv on Ubuntu and macOS is something we want users to do? This is also the case for the mavproxy_SIYI module as the video streaming support in MPImage also requires opencv with GStreamer support, so perhaps it's already assumed?

[rmackay9]

Hi @srmainwaring,

I've also looked at the MAVProxy Siyi module and I think we will need to create a separate, more general purpose camera gimbal control screen. Hopefully we can re-use some things that the Siyi module has added to (like the MPImage class).