Goal: Stream to Android
Goal: streaming the Gem-window of a Linux Desktop to a VR-headset running on an Android phone.
This page documents different possible approaches and hopefully will show how it's done when successful.
Unsucessful Apporaches
apps
If you are on Windows, you have some choices for apps:
using x11vnc
Use the command xwininfo to find out the ID of the window to be shared, then use x11vnc -id {id number here} to share only one window to the vnc client.
However cardboard-vnc-free is doing too much. First of all, it controls the moise pointer on the server (as a VNC client should) but I don't need that. There is an option "Viewer" in the connection settings that will diable this and lower the latency from about 3 seconds to 1 second.
cardboard-vnc-free is also adding two viewports to the shared image, to fake a 3D. That's a show stopper, because I want to use the stereo mode in GEM.
udpvideo lite/ffmpeg
Since streaming to a VR-Headset with minimum latency is pretty much what you want with a live drone video this abandoned freeware app is doing exactly that: udpvideo lite
Then run on the desktop: ffmpeg -f x11grab -video_size wxga -r 25 -i :0.0 -f mpjpeg udp://192.168.1.2:5678