How to capture PCM data from Wave Out

Question

How would it be possible to capture the audio programmatically? I am implementing an application that streams in real time the desktop on the network. The video part is finished. I need to implement the audio part. I need a way to get PCM data from the sound card to feed to my encoder (implemented using Windows Media Format).

I think the answer is related to the openMixer(), waveInOpen() functions in Win32 API, but I am not sure exactly what should I do.

How to open the necessary channel and how to read PCM data from it?

Thanks in advance.

Answer 1

The new Windows Vista Core Audio APIs have support for this explicitly (called Loopback Recording), so if you can live with a Vista only application this is the way to go.

See the Loopback Recording article on MSDN for instructions on how to do this.