The Virtual Video Tool is distributed as the following components:

• Virtual Video Mod: OVVV is built on the game Half-Life 2 from Valve Software (see the following section for obtaining Half-Life 2). This component includes the dlls and other modifications to the standard Half-Life 2 installation that comprise the 'mod'.
• DirectShow Filter: A Windows component that allows you to stream live virtual video into Media Player or into your own application using the DirectX SDK.
• C API: A C library of functions to stream virtual video and control PTZ cameras from your own application as an alternative to the DirectShow filter.
• Reference Manual: PDF file describing the usage of the above components. The same information is also available on-line in the Usage pages.

Download and installation of the above components is described in the following sections.

The ObjectVideo Virtual Video Tool is provided free for non-commercial use, for your own research and development purposes. If you publish or distribute images, videos or derivative results based on this software, you must acknowledge ObjectVideo including the name "ObjectVideo Virtual Video Tool".

Due to changes in the network protocol, the Virtual Video Mod, DirectShow filter and C API for version 2 are not interoperable with version 1. Applications based on the DirectShow filter version 1 do not require any code changes to work with version 2, but applications based on the C API version 1 will require minimal modification to use the new PTZSetStatus function declaration.

The following features are new for version 2:

• Automatic target ground truth generation (see Ground Truth)
• Selectable PTZ control modes: relative/absolute position and velocity control (see PTZSetStatus C function and Set PTZ Status network command)
• Catadioptric omni-directional camera model (see omni console command)
• Gaussian blur defocus effect (see noise_defocus console command)

The ObjectVideo Virtual Video Tool is freely distributed 'mod' of Valve Software's popular Half-Life 2 game, and a licensed copy of the game must be installed before installing and using OVVV. Half-Life 2 may be purchased and downloaded online from steampowered.com. Alternatively the game may be purchased on CD-ROM from most game retailers.

Notes:

• You will need to download the Steam content management client before purchasing the game online.
• If you are connected to the internet through a firewall, you may need to ask your system administrator to open specific ports before using Steam. Further details.
• After purchasing Half Life 2, you can obtain the Source SDK (including map editor and source code) for free through Steam. See this FAQ item for more details.