I want to write a driver to detect(intercept) audio data to sound card. 
Basically, I do not want  to process the audio data after to detect.
If the driver detects audio data, it will information other hardware device 
to show helpful information. What is the best approach to do this?

1.  Writing a audio filter driver? --------------Intercept IOCTL from KS
2. Writing a virtual audio driver? ------------- It seems to be not 
necessary for my case.

I  did some researches over the internet and someone said that

    1. Audio filter driver cannot intercept all audio data from all system 
interfaces. Is that true?
    2. Audio filter driver cannot be installed on Vista or latter platform. 
Is that true?

If audio driver is not  suitable for me, what is other alternativeness?

 

>    2. Audio filter driver cannot be installed on Vista or latter =
platform.=20
> Is that true?

I think it is called "global APO" and requires the digital signature =
same way as x64 kmode drivers.

So, if you provide DRM-breaking software, you will be traceable :-)

--=20
Maxim S. Shatskih
Windows DDK MVP
maxim@storagecraft.com
http://www.storagecraft.com