open source audio sniffer/grabber for windows 7/vista

This is a directshow audio filter source that uses the loopback capture of windows vista+ to capture live audio.
I.e. it’s an open source (free) competitor to virtual audio cable, basically

virtual-audio-capture-grabber-device was the old url

Basically with windows XP, you could record “what you hear” by selecting stereo mix from your “recording properties” and voila, it would record (note: this option is only available if your sound card supports it, so not all XP users could do this).

With windows Vista/7, this is also an option–go to control panels -> manage audio devices -> Playback tab, right click and check the various “show hidden/disabled devices” and then select “stereo mix” again.


If that works then you don’t need my little program here, you are good to go.

Unfortunately this is only available if your sound card drivers support it, and most for windows 7 audio drivers seem to *not* support for this.

There is an answer–WASAPI Loopback recording is available on windows vista+ allows you to do essentially the same thing [1]

but using software only.  This project attempts to create a directsound audio input device that “reads” from that source, i.e. basically allowing any directsound aware apps (ex: VLC) to be able to record what you hear.  It works, feedback is welcome.

Some other options would be (you don’t need to do these, you can just use my program though):

buy a new (or another) sound card, or buy a physical cable and connect it from your headphone jack to your linein (or mic) jack, then use that, or purchase either or “virtual audio cable” (the former looks less confusing) or or the like.


18 thoughts on “open source audio sniffer/grabber for windows 7/vista”

  1. Hello, I hope you’d resume working on this project. Seems like my sound card’s wave input has some weird problems, so having a working solution for getting the Vista/7 audio capture as an audio device would be great. And I don’t exactly want to buy something that should IMO even come directly with the OS itself.

  2. interestingly I received another request via github a few days ago. That makes the first two requests since I posted this 8 months ago, so I guess I’ll add it to the todo list but probably won’t get to it for awhile. If anybody else wants it to happens PLEASE POST A COMMENT so I know it will be useful for anybody.

  3. Excellent! Worked out of the box. Thanks so much for this outstanding work.
    Would it be technically possible to use this (or something similar) on the line-in or mic-in, too?

  4. with linein or mic you should be able to just “record it straight” (without any extra software) or you can [with some effort] get your mic and/or linein to “output through the speakers” in which case I think this would work…

  5. Do you have any plans to complete this in terms of VAC features? (Reinjecting audio from one virtual sound card into another, for example?) I think it’d be really cool if it’d have REAL cables (Propellerhead Reason does this with its synths etc. well not necessarily as complex)

  6. Excellent staff. thanks so much for creating this.
    The only thing that’s missing for me is the RTMP streaming option. I think this will be great addition if you can make it.

  7. Nice job!
    Could you provide all snifers “ax” for Windows 7 – x64?
    They make installation much easier.

  8. Hi Roger!
    That’s it: I just want the .ax files. Like, I’d like to get and then I’ll use regsvr32 file to register them.

  9. this fiter woks fine on win7,but i can not be registered on some win10 machine for the filter needs some system dll whick can not be found on the window OS for example WIN 10 Education VERSION.

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