Virtual audio driver for Windows?

Question

Is there any (possibly free or open-source) virtual WDM audio driver for Windows, with additional processing plugins, which would add one more layer between windows applications and actual sound card's audio driver, allowing to:

• Add software DSPs to general audio output. I would like to be able to use custom effects, like compressor, or stereophonic-to-binaural converter for listening online streaming media on headphones, etc.

• Connect its output to some custom buffer instead of the sound card. For example, to be able to record audio, or to send audio via wireless connection to some other wireless source?

I know only about VAC driver, but don't know how I would use it to do any of these tasks. And unfortunately it is not free.

Also, audio driver was just my idea how to solve these issues - if you know other way, please share your knowledge.

I need this for Windows 7 and/or Windows XP.

Solution 1

There is now a free (donationware) alternative to VAC Virtual Audio Cable. Check out VB-Audio Virtual Cable.

There are 32 bit and 64 bit drivers available to support one virtual cable. This cable appears to support 8 channels (7.1 surround) can handle 96kHz sample rate, and has an adjustable buffer size.

Solution 2

Then there are several drivers working even without any physical sound card present:

• e2eSoft VSC - Virtual Sound Card https://www.e2esoft.com/vsc/ (US$19.95)
• ShiningMorning's Virtual Audio Streaming http://www.virtualaudiostreaming.net/ (US$29.95 for private home use, more for commercial use)

but these two have no ability to apply effects, AFAIK.

Solution 3

If you can deal with support for Windows Vista and later only, you can program in custom effects to the audio stack (the audio device graph, hosted by audiodg.exe)directly for applications using the following APIs:

• WinMM (the oldest and most compatible sound API on Windows)
• DirectSound
• WASAPI in Shared mode

The following are unsupported:

• Kernel Streaming (KS)
• WASAPI in Exclusive mode
• ASIO

The feature that allows you to program your own filters is called Audio Processing Objects and more info is available from Microsoft here (should be a stable link) with more detail here.

Note that all of this is laughably easy with Gstreamer and Pulseaudio on Linux; if you can get a similar stack to become the backend for all Windows audio, you won't have to do all the ugly machinations of a sAPO implementation.

Comments

[Jimmy Zelinskie]

I was looking for something that would add a playback and recording device on Windows so that I could stream audio from selective applications using OBS. The HiFi-Cable on the page you linked has worked with less latency with no configuration than anything I could configure with Virtual Audio Cable. Now I can stream rhythm games (osu!, beatmania) via OBS and exclude VoIP software (mumble, skype) from the stream.

[JvO]

That link is dead; seems to hosted under vb-audio.com/Cable now.