I hope this is the right group for my question.
Actually, I'm not sure exactly how to phrase the question, so here's
I'm trying to do:
It boils down to doing Active Noise Reduction "the hacker way" --- I
to get some off-the-shelf tiny microphones that I would glue to the
external part of my headphones, feed it through the Microphone input
of the sound device, and then manipulate that to add it to the ouput
the sound card.
Now, two things:
1) I want to do that *regardless* of what or who is controlling the
to the audio device (that is, regardless of whether I'm playing a
playing Ogg or MP3s, or viewing some audio-enabled web page or
enabled sites, Youtube, etc.)
2) I need to manipulate the microphone signal --- add a small delay
possibly some digital filtering; that part I'm 100% comfortable
do have some background in DSP, and I can handle all the required
programming in the C/C++ realm)... But I don't know how to
get the data in real-time and mix it with the output at a low-
level that it won't matter who's playing what sounds, the
signal would get added to the output.
Any ideas or pointers?