September 16, 2005

Flash in a flash with DemoStudio

Author: Chris Lynch

DemoStudio is a GPL-licensed screen capture application for Microsoft Windows that can record single screen images, a series of screen images on a set interval, or screen video and audio. Whilst the screen capture functionality of DemoStudio amounts to little more than an organised version of Ctrl-PrintScreen, the audio/video capture functionality is superb, most notably for the software's ability to create live screen annotations and to convert its initial AVI format output to Flash.

Installation of DemoStudio is simple, with a standard Windows installer provided for the application. After installation, the Recorder application should be your first point of call. The Recorder can capture a complete screen or a screen region, which you can select by dragging a region on screen at the start of the recording. You can control the initial recording to an impressive degree, managing frame rate and colour depth as well as controlling the codec that will be used to encode the output video. One minor gripe about the Recorder is that it can record only from Windows' primary monitor; if you are running dual video cards, or a video card with dual outputs, you will be able to record only from one of your screens.

When recording, you are free to use your machine as normal. I noticed no decrease in the performance of my machine whilst recording, even when running the record at 40 frames per second (FPS) in full screen mode. By default, the recorder minimises itself to your taskbar when recording begins, but you can keep it visible if you want to keep track on the length and
size of your video or if you want quick access to some of recorder's other functions.

Pausing live video and adding annotations

One of the most useful functions of DemoStudio's Recorder is its ability to pause recording at any time. This can be particularly useful if you are recording a demonstration of software and waiting for a long process to complete. The pause function can be used to ignore "dead time." The pause function can also give you "breathing space" if you are recording audio along with your video. You don't need to be a practised speaker to work your way through your application if you can "take a breather" every few steps!

DemoStudio allows you to create screen annotations in real time, even when you are recording video. These annotations are seamlessly overlaid onto your screen image, working as borderless windows with a transparent background, and can be easily moved and resized. You can add text to every annotation, with control over the font as well. If you have multiple annotations on screen at any time, they can be be grouped together and saved for later reuse.

The basic screen annotations supplied with the software take the form of arrows, speech bubbles, and clouds. The background colours used for these initially appear somewhat garish, but in practice stand out well from the normal Windows colour scheme. You can create new annotations or edit the existing ones with any simple graphics application.

Combined with the Recorder's pause function, screen annotations take DemoStudio's recordings from simple records of screen activity to something far more useful. You can pause recording sessions multiple times to add, edit, and remove annotations, with all of these changes appearing seamless in the end video.

The possibilities presented by this are impressive; I have used DemoStudio to create instructional videos and to support fault tickets, recording and annotating the software fault as seen on my machine. If a picture paints a thousand words, how many words are there in 60 seconds of 40FPS video?

Flash conversion

DemoStudio records by default to AVI format, but provides an excellent tool called DemoStudio Producer for converting these into Flash (SWF) files.

Conversion to Flash can be made part of the recording process, automatically taking place after you press "stop" in the Recorder, or can be processed separately. Personally, I choose to convert to Flash immediately, and configure the application to remove the normally large source AVI from my machine.

Again, DemoStudio provides an impressive amount of configuration around the Flash conversion. You can change frame rate and colour depth with each conversion, as well as the output format (for compatibility with Flash 5/MX and Flash editing tools). You can also choose to include playback controls (simple play, stop, and pause options) in your output Flash.

Conversion to Flash can take up to a few minutes, depending on the frame rate and resolution of the source file and the output frame rate required. The end result, however, is excellent, and can be seen immediately after the conversion has run. DemoStudio also outputs an HTML file that contains the tags required to embed your Flash output at its correct size in a Web page.

Dependant upon size, frame rate, and other factors, the output files range in size from just 100K for a short, small video to just over 1MB for 60 seconds of 1024x768-pixel resolution at 20FPS. You can create larger videos, but as Flash lacks the streaming capabilities of formats such as QuickTime, you should take care when deploying these.


Anyone who wants to produce short, transportable, high-quality screen captures for training, documentation, or error logging of Windows applications could benefit from having DemoStudio on their desktop. It's a mature piece of software, and proof that open source applications can compete on the Windows desktop as well within Linux.

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