Reading audio stream to output device

Question

I was curious if there is a way to read the data that is being sent to an audio output. My end goal is to capture the audio and then send it over serial for audio processing. I'm using a Windows computer.

The thing that seems to be making this more difficult is that I'm not reading the captured microphone input, but rather the streamed speaker output.

Can anybody help me out?

Answer 1

A more or less easy way is to take advantage of Stereo Mix device, where available. This way you have an audio capture device, which makes you available device audio output mixed down. You can read from this device as if it were a real audio input device such as Line In, or a microphone, using standard and well documented APIs or audio libraries.

Other options are more sophisticated and require both hooking into system and deeper understanding of the internals: you either hook audio APIs to intercept what applications send to audio outputs, or you install a virtual audio device the applications use and you have the data available from.