Is there anyway to read the audio outputted by a program/the soundcard? Sort of like, reading the audio output of itunes, or firefox. I've searched around and I can't find any way to do this as it requires interfacing with the soundcard.
Any help is appreciated!
Once you send music to a sound card, it will be beyond java to connect to the sound card, as that will be low-level programming, so you will need to do some kernel level programming, which won't be trivial to do.
But, even if you go low-level, I doubt you will be able to tap after the sound card, and before the speaker.
You may be able to intercept before the sound card, but that depends on your OS and your sound card type.