To make it short: ubuntu + pulseaudio + gstreamer + icecast = my computer's sound on the internet
And it works. I use this command:
gst-launch pulsesrc device=combined.monitor ! lame ! shout2send mount=/a.mp3 port=8000 ip=localhost password=...
And it does what I need, by opening that "a.mp3" elsewhere someone can hear "every sound my computer makes"
But... For some reason this only works if something on my computer playing sound. If not, that a.mp3 is not available, and every connection to my server closes.
Playing a silent audio file forever in the background would solve the issue, but that is a very dirty workaround. Any tips?