How to write virtual audio device driver for WinXP

Question

How to write simpliest audio virtual device driver in WinXP? I know that one way is to write a WDM driver but I suppose it is not an easyly task. I need to implement some audio filtering for a Flash based application. Unfortunatelly it seems that it is the only way to do it - outside a Flash, by a device driver, then a Flash app can attach to my virtual device. I was wondering if I can write a device driver using some high level API (higher that WDM), maybe UMDF as virtual usb audio device(?) or maybe only some dll which will register a virtual device. As I can see Google Talk plugin contain googleadapter.dll which provfides virtual webcams, I wonder how they wrote it.

Thanks in advance, ternyk

Answer 1

For WinXP it is enough to write Installable Driver which is a simple user-mode dll. However it will not work under Vista or higher because they have different audio model.

Answer 2

What API? First thing i'd worry about is learning how the app(s) interface with Windows and the best way to do this is to actually learn how to code an application with audio using the same interface. So, if it uses DirectSound audio, learn how to code an application which uses DirectSound.

The reason i say this is that once you know how your code works you will also know what API need to be hooked. Then it goes from there, code the loader/dll injector so that it performs what you're after.

Finally, don't forget to use Google to do as much research on your own first:

[quote]Give a man a fish, he'll eat for a day... Teach a man to fish and he'll never go hungry again...[/quote]