Screen Capture

You can grab computer screen and send it with UltraGrid.

Linux and OS X

In Linux and OS X there is screen capture card you can use to capture desktop:

uv -t screen 

Windows

For Windows, you will need to have screen capture DirectShow filter which can be obtained as a part of this package. After installing that, one of DirectShow capture devices will be "screen-capture-recorder". Provided that it is first device (determined by "uv -t dshow:help"), you should be capture with following command:

uv -t dshow:1 

Note: In Windows 7 you may want to disable Aero for better performance (Start->Control panel->Appearance and Personalization->Personalization and select "Windows 7 Basic" instead of "Windows 7").

Customizing video properties

The screen-capture-recorder DirectShow capture filter goes with predefined frame rate 30 and also capped video dimensions. This, however, can be increased by changing values in Windows register (eg. using regedit) – find a key HKEY_CURRENT_USER\Software\screen-capture-recorder (create if unset) and in that, you can add following DWORD subkeys:

• default_max_fps
• capture_width
• capture_height

For more details you can refer here. More parameters that can be set by the regedit can be found in this Ruby source (members of array Settings).