TVirtAudio - Virtual Audio Driver SDK for Windows 11 and 10

Thesycon’s TVirtAudio solution is a Software Development Kit (SDK) that enables Windows application developers to capture audio that is played by an application, process it and provide it to other applications. At the heart of the solution is a virtual audio driver which manages the virtual sound devices and signal paths created and controlled by the application via its private API. To connect virtual audio channels internally, the driver implements a mixer which can be controlled by the application.

TVirtAudio is a software-only solution. There is no dependency on specific hardware.

Virtual Audio Driver with Mixer and ASIO

Feature Summary - Virtual Audio Driver for Windows

The driver is fully configurable and programmable through a private API exposed in user mode. The control/status API supports:

Create/Destroy a standard Windows output sound device which shows up in Windows Sound Settings and can be used by standard applications to play sound.
Create/Destroy a standard Windows input sound device which shows up in Windows Sound Settings and can be used by standard applications to capture sound.
Virtual sound device properties can be configured, including: channel count, sample rates, name and type (icon).
Create/Destroy virtual ASIO channels which are exposed by an ASIO driver to be used by professional audio applications such as a DAW.
Create/Destroy private channels which are available at a private streaming API. The application uses these channels to transfer audio data from/to the internal mixer.
Control the internal mixer to route and/or mix audio channels. The mixer supports arbitrary routing from input channels to output channels.

Audio Synchronization Model

The TVirtAudio driver supports multiple mixer instances. Each mixer instance represents a clock domain with a clock source. All virtual Windows and ASIO channels connected to a mixer are synchronized to the mixer’s clock source.

The driver supports two kinds of clock sources:

System Clock – The driver creates the clock internally based on the operating system’s high precision timestamp support.
External Clock – The application provides the clock via driver API calls. In this case the clock can be derived from an arbitrary audio stream source or sink.

Signal routing across mixer instances and clock domains is not supported. The driver does not implement sample rate conversion.

Application Scenarios of Virtual Audio Driver for Windows

The generic virtual audio routing and synchronization capabilities of the TVirtAudio driver can support many different application scenarios. Some examples are given below.

Virtual Output Sound Device

The application creates one or more virtual Output (playback) sound devices and connects the channels to the driver’s private streaming API. Through this API, the application receives the audio data that is played by a standard application. The data can be written to a file, streamed to the network or played through another sound device such as a speaker, for example.

Virtual Output Sound Device

Virtual Input Sound Device

The application creates one or more virtual Input (capture) sound devices and connects the channels to the driver’s private streaming API. Through this API, the application provides the audio data that will be recorded by another application. The source of the data can be a file, a network audio stream or another sound device such as a microphone, for example.

Virtual Input Sound Device

Virtual Output/Input and Custom Sound Processing

As a combination of the two scenarios described above, the application can receive the audio data that is played by another application, process it, and provide the result to other applications. Processing can change properties of the audio stream including channel count and sample rate. Processing can also involve splitting or merging multiple virtual Output streams into multiple virtual Input streams.

Virtual Output/Input and VST Based Sound Processing

Virtual Output/Input sound devices and/or virtual ASIO instances can be created which connect to mixer input and output channels. Another, dedicated, virtual ASIO instance is used to run a DAW or VST host application which processes the sound that is routed from mixer input channels to mixer output cannels. If a private VST host application is used, the dedicated ASIO driver used for the processing can be hidden so that it is not visible to a standard DAW.

Virtual Audio Cable

The application creates a virtual Output and Input sound device and connects them via the driver-internal mixer. The sound played by one application through the virtual Output device can be captured by another application using the virtual Input device. Multiple instances of such cables can be crated. Channel splitting and merging can be supported using the internal mixer.

Scope of Delivery

The TVirtAudio SDK includes:

Kernel-mode driver packages for the supported operating systems
Driver installation utility to be integrated into a surrounding application installer
ASIO driver (ASIO support is optional and must be licensed separately)
Driver API as DLL with C-style functions plus C++ wrapper classes (can be used from other programming languages such as Python, C#, Rust as well)
API documentation in HTML format
C++ sample code that demonstrates usage of the API

Supported Platforms

Windows 11 arm64
Windows 11 64-bit
Windows 10 64-bit version 1803 or later
Windows 10 32-bit version 1803 or later
Windows Server 2019 (64-bit) or later

Software made in Germany

Our software is purely designed and implemented by our team in Germany - no outsourcing. Technical support is provided directly by the developers.

Free Demo, Licensing conditions & Prices

To receive a free demo, prices or license agreement, please fill out the contact form.

The free evaluation version of the TVirtAudio driver works for an interval of 60 days without any limitation. After that evaluation period has expired, the driver stops working.

NOTE: The driver described on this page is *not for use by end users*. It will not help solve any problems you may experience with a consumer device such as a webcam, camcorder, card reader, external sound card, etc. Thesycon’s device drivers are software components intended to be used by hardware or software manufacturers to create end products.

Current Version: 1.0