Getting raw audio data

[BOMEz]

I'm trying to read raw audio input say from a guitar or keyboard from my line in port on my sound card, to read the data and analyze what notes are being played.

How do I even begin to do this?

Some people have mentioned using DirectSound, which I'm currently investigating (installing right now) but I just wanted to see if anyone else has recommendations ?

NOTE: Though I posted this is C#...I'm open to any language really...its just that I expect the Dirext X (which has DirectSound...I think) and I'm also open to using any OS.

[vekipeki]

Most of soundcards also support ASIO interface, which is used for low-latency reading/writing. If your driver doesn't support it, there is a free universal driver here: http://www.asio4all.com/ which should work.

If you want to access it using .Net, check this article: http://www.codeproject.com/KB/audio-video/Asio_Net.aspx. ASIO is used by most digital recording apps (Cubase), and it's the preferable way of working with sound if you want precise results.

After you get the raw input data, you will have to do some FFT processing to get the harmonics.