Oh, ok I surrender, I added an Autodetect choice for the soundcard in the gui, and I fixed the detection of the sample rate which was linked to the sound driver instead of the soundcard... !
You won't have a test binary for now because after the forum, it seems the ftp is broken for now, I can't send raine.7z ! (deleted the file to avoid any mistake).
It's still a rare case in my opinion, but it's quite interesting to see how it can be done without having something too big. Since I had to fix the sample rate detection too it's a little longer than what I anticipated but it's still ok, and maybe someone else would use that !
Notice that the behavior is the same as before : if you don't choose "Autodetect" explicitely and you have no config file, then it will detect the soundcard only once, there's no reason to detect it all the time except on a crazy laptop changing its output device all the time !
Difference from before : now if you change the soundcard in sound options and the sound card driver has a preferred sample rate, you'll see this sample rate selected in the options in real time. Not all drivers have a preferred sample rate, if there is none the frequency is not changed.
By the way the error on the server is because of a full disk !