I am going to apologize in advance for being extremely vague, but my knowledge in this area is somewhat limited so I don't know the neccessary "keywords" to make my point/question clear. Sorry.
What I want to do is to find a way to obtain access to raw audio data as it is being output, say, when some external application is playing back music, when data is passed from the microphone to the output device and so on. I want to have access to that data in real time (well, almost real time, anyway), so that I can analyze/visualize it, etc.
I know, that it is certainly possible, as I've done it a long time ago in Java (I think I was using Processing and Minim libraries). This was done in windows by enabling a sort of "loopback" input device on the sound card (I think my vendor called it "Wave Out Mix" or something). How would one approach the same problem under a Linux-based OS?
I intend to use python for the analyzing/visualization part, however I can work in C if it is neccessary to get to the raw data.
Thanks in advance for any information.