You can capture video of all of the amazing things happening on your desktop with one of Linux's many screencasting applications. These programs are perfect for creating demonstrations for blogs and tutorials, and for illustrating projects with more than just still images.
Many different programs are available, and they all provide a different set of features, options, and output formats. When choosing, consider the degree of control you want to have over your video resolution and whether the video is intended to work on non-Linux operating systems. Common open source output formats, such as FLAC and Ogg Theora, work natively on Linux but require software and plugins on proprietary operating systems. User interfaces also vary greatly; some applications are nothing more than an icon in the system tray while others depend on large interfaces with many options.
I tested three popular screencasting applications to see which is best for everyday use. I evaluated the user interface, the quality and variety of output formats, and the ease of installation and obtaining the required dependencies. I tested the programs on a MacBook Intel Core 2 Duo with 4GB of RAM, dual-booting into Ubuntu 8.04 Hardy Heron.
Istanbul is a simple desktop recorder that lives in your system tray. Clicking on the icon starts the recording session, and clicking it again ends it. The video is encoded in the Ogg Theora format. You can capture the full screen, a selected window, or a portion of the desktop, with or without sound.
This application doesn't have a complicated user interface, making it easy to use, but there are some drawbacks. Although you do have some control over the resolution size, you cannot change the output format of the video file. This isn't much of a problem if you're going to upload the video to a Flash-based video site, but the Ogg Theora format doesn't work out of the box of the main proprietary operating systems without an application like the VLC media player. Therefore, you'll have to convert to a different format if your intended audience requires it.
Istanbul is easy to install, and it is included in most distribution repositories. In Ubuntu, I was able to install it with the Synaptic Package Manager. It requires PyGTK and GStreamer, which are common dependencies.
Wink is geared toward making video tutorials; it compiles a series of screenshots to a Flash format, and allows you to edit the video directly and add text boxes, navigation buttons, and still images. It includes many advanced features, such as the ability to create preloaders (elements that load portions of the video before it starts playing) and control bars for the Flash playback.
The interface is not as minimal as Istanbul's, but it is still relatively straightforward. The main drawback of Wink is the video output formats: Flash and Windows .exe programs are good for viewing the video when the file is local or when it is hosted on a personal Web site, but you can't upload Flash and .exe files to most social networking and video sharing sites. Wink is good for corporate entities who want to share a tutorial with staff, but it is less useful for home users who want to show off their desktop on YouTube.
Most distributions include Wink in their repositories, and you can install it with any package management application. Unfortunately, though, Wink doesn't work with Ubuntu 8.04 as of the writing of this article without some hacking. I tested it for this review with a previous version of Ubuntu.
With XVidCap, you can capture desktop video and take single-frame screenshots. You can record portions of the screen by dragging a red selection rectangle over the area you wish to capture. The program can handle a wide variety of output formats, including MPEG, AVI, Flash, and QuickTime.
The interface consists of a small toolbar with more options tucked away inside a Preferences panel. XVidCap uses the FFmpeg libraries to capture video or a series of images, and it can also embed audio. Some people claim that XVidCap can dramatically slow down your computer if you try to record a large area. I didn't have that problem on my machine, but I had 4GB of RAM.
Installation of XVidCap is easy because it comes in the repositories for most distributions. It requires common dependencies, such as libavcodec (the FFmpeg codec libraries for video), and Cairo, Glade Interface Designer, and GTK+ to render the graphical interface.
XVidCap is the most versatile of these three tools for recording your desktop and creating screencasts. Istanbul is a close second, but its lack of support for a variety of different output types is a drawback. Wink is nice, but it's limited in use to only a few tasks, and it's not for users who merely want to record their desktops. XVidCap can handle many popular video formats, allowing it to play nice with both Windows and Mac OS X. The red selection box is kind of clunky, and there is no easy way to record only a specific window without it, but XVidCap gets the job done
in an efficient manner.