CloudXR Virtual Audio Driver#

On Windows runtime hosts, the CloudXR Virtual Audio Driver provides dedicated CloudXR audio endpoints. The driver creates an NVIDIA CloudXR sound controller. When the CloudXR Runtime starts, it creates a dedicated speaker output and a dedicated microphone input under that controller.

The dedicated speaker output can be used for downstream audio streaming from the PC to the client. The dedicated microphone input is required for upstream microphone audio streaming from the client to the PC.

The CloudXR Runtime SDK includes the driver package files:

  • nvcloudxrvad.inf

  • nvcloudxrvad64v.sys

For the runtime property reference, see CloudXR Runtime Management API.

When the Driver Is Required#

The CloudXR Virtual Audio Driver is required for microphone streaming. Install the driver before starting the CloudXR Runtime when using mic-streaming. The runtime audio-streaming property must also remain enabled for microphone streaming to work.

The driver is not strictly required when the application only needs downstream audio from the PC to the client. Without the driver, the CloudXR Runtime can capture the system speaker audio for downstream streaming.

However, the driver is required when the application needs isolated downstream audio. In that case, configure your application to write audio to the dedicated CloudXR speaker output. CloudXR can stream that application audio without mixing in other system-wide audio. For example, if a user plays audio from another desktop application at the same time, that audio is not mixed into the CloudXR stream when your application writes to the dedicated CloudXR speaker output.

Manual Installation for Development or Testing#

For development and test systems, install the driver manually through Windows Device Manager:

  1. Open Device Manager.

  2. Select Action > Add legacy hardware.

  3. Select Install the hardware that I manually select from a list.

  4. Select Sound, video and game controllers.

  5. In Manufacturer, select Generic USB Audio.

  6. Click Have Disk.

  7. Browse to the CloudXR Virtual Audio Driver folder that contains nvcloudxrvad.inf.

  8. Complete the driver installation.

Application Installer Integration#

Applications that integrate CloudXR Runtime should install the CloudXR Virtual Audio Driver from the application’s installer. The installer must create the virtual audio device and install the CloudXR driver package for that device.

Create the virtual audio device with the hardware ID USB\VID_0959&PID_9004. After creating the virtual device, install nvcloudxrvad.inf on that device by calling the Windows API UpdateDriverForPlugAndPlayDevices with the same hardware ID. See the Microsoft UpdateDriverForPlugAndPlayDevicesA function documentation for API details.

The Microsoft Windows Driver Samples devcon source demonstrates this SetupAPI pattern. See the devcon cmds.cpp source for reference.