Is it possible with ffmpeg grab a window that is minimized or that not has the focus (there is another window over but ffmpeg records only the window which is below)?
With a command like
ffmpeg -f x11grab -r 30 -i :0.0+x,y -f flv rtmp://url?
AFAIK it's not possible to capture a specific window with ffmpeg, the x11grab entry in the manual only refers to screens https://www.ffmpeg.org/ffmpeg-devices.html#x11grab and it suggests that the region you specify is static (if you move the window ffmpeg does not follow it):
However GStreamer offers some more flexibility in this case:
gst-launch-1.0 ximagesrc xid=0x04000007 ! videoconvert ! autovideosink
This works with out-of focus windows and you can even move them but it does NOT work with minimized windows.
As you may know, you can get the window id with
You can see the options supported by GStreamer elements using the
gst-inspect-1.0 program, e.g.: