The Harrier USB SDK has been developed for use with USB Video Class (UVC) compatible Harrier and BlueBird products and Windows 10. It provides classes, a library of functions, classes and example applications (source code available on request) that acquires UVC video/images from UVC compatible Harrier products, e.g. the BlueBird SDI Adapter and the Harrier USB/HDMI Camera Interface Board. Active Silicon UVC compatible devices stream video from their input ports (e.g. 3GSDI/HD-VLC) to their USB 3 output port. The Harrier USB SDK example applications acquire video/images (over USB) from Harrier UVC compatible products, and can also be used to change the camera video output mode and other camera UVC properties via the USB connection.

With Active Silicon UVC compatible devices, the application software can use several standard APIs, including Microsoft Media Foundation or DirectShow. The Harrier USB SDK is based on Microsoft Media Foundation. It is a set of modules, classes and example source code designed to enable quick and easy development of UVC based applications that capture video/images from Active Silicon UVC compatible products. Microsoft Media Foundation enables the development of applications for using digital media on Windows 7 and later versions of the Windows OS. The SDK provides objects that acquire, encode and display video. The classes in the SDK can be used as-is in an application, or as an example to develop a custom application based on Media Foundation.

The SDK example of video encoding uses a Media Foundation Transform (MFT) which must be installed on the host machine. The default H.264 MFT available under Windows runs entirely in software and does not use any hardware acceleration. Hardware-accelerated MFTs are available from Intel or NVIDIA; both require the appropriate acceleration hardware to be available (e.g. an Intel CPU with QuickSync support, or an NVIDIA GPU with built-in NVENC support).

C#, VB or C++/CLI support
The Harrier USB SDK contains a .NET wrapper that enables the SDK API to be called from .NET based languages (C#, Visual Basic [VB], C++/CLI). This enables developers to write code in C#, VB or C++/CLI to implement image acquisition, display and video recording functionality using the Harrier USB SDK. The HarrierView example video application has been written in C#.

Example Applications
The example applications included with the Harrier USB SDK implement the Active Silicon and Media foundation functions/classes can be used to create working applications. Full source code for the application is available from Active Silicon on request. There are two examples:

1. HarrierView: implements UVC video, H.264 encoding, video recording and camera control using UVC properties.
2. HarrierEx: implements UVC video, H.264 encoding, video recording, still image capture (JPEG/TIFF) and, Text and image overlay.

Harrier Virtual COM Port
The Harrier Virtual COM port driver is installed with the USB SDK (Windows only). When a PC (with the driver installed) is connected to a Harrier USB/HDMI interface board, the Harrier Virtual COM Port Driver will start. The COM port will appear in Windows 10 and can be used to read and write VISCA data to the camera in the same way as a standard serial COM port. The COM port does not need to be set up with parameters such as baud rate, parity, etc. as the VISCA data is actually communicated over the USB connection. Note: the Harrier USB/HDMI interface board must have the DIP switches set to enable USB communication.

Linux Support
As Harrier products are UVC compliant they will operate under Linux when a UVC driver is installed.
For more information on working with video and UVC drivers please see the relevant Linux documentation for your Linux distribution, for example:

https://help.ubuntu.com/community/Webcam
http://www.ideasonboard.org/uvc/
https://www.kernel.org/doc/html/v4.13/media/v4l-drivers/uvcvideo.html

Direct VISCA communication with the camera is possible using the Harrier USB Linux API. This is a simple API/library that enables messages to be sent/received to/from the camera over the same USB connection used for the video. The library and example code is available from the Downloads tab in two variants, one for PC only and one that also includes support for ARM.
Note: this is an API/library, not a virtual serial port.