Ripping sound from online video through soundcard?
This feature is dependent on the soundcard, especially if mixing is done in hardware. Creative soundcards have a special mic channel called "What-U-Hear", not sure about other sound cards. If you don't have one available, you might have luck searching for a "Virtual Sound Card". There is a virtual ESD sound card which would allow you to send an audio stream to a recording server, but I believe it is long unsupported and doesn't work with recent versions of windows.