ExpanDrive

We recently added a screencast to the front page of SftpDrive.com, it’s a good place to start if you’re not entirely sure what SftpDrive does or what it is different.

Screencasts are an incredible way of cleary conveying what a program does or how it is supposed to be used. It allows you to walk anyone through a complex sequence of events at a specifically chosen pace and add however much additional instruction or annotation that is needed.

The tough part is making them. You’re often confronted with a choice between a small file with blurry images or a gigantic file that is still imperfect. To get it right requires some experience and finesse. You’ll probably also want some expensive software if you’re going to do a real bang up job. Forget about all the effort it takes to learn how to use it.

What if you want to just make a simple screencast and not have it suck? I thought I’d write a bit on how we attempted to achieve that lofty goal.

While ours doesn’t have as much Sexy as what Apple puts together for the iPhone’s guided tour, we think it does a pretty good job and I thought I’d write a bit about how we made it. Most people make screencasts by recording a video of the screen and then wrapping it with a Flash based player. A major problem with this basic technique is that nearly all popular compression algorithms are poorly suited at compressing videos of a computer’s user interface. An image of a computer UI is often full of very high frequency image content. Everywhere you look there are edges and contrasts. Dark fonts on a white background. Window borders. Well defined buttons. This high frequency content is what popular codecs are terrible at. Take a look — you get some nasty artifacts.

To combat this, along with having some easy to use facilities to edit and publish - we chose the tool Demo Builder. It operates a bit differently than the rest. Instead of capturing the screen 10 or 15 times per second, Demo Builder captures the screen far less often. It takes snapshots at regular intervals or upon request. While doing this, it continually tracks and records mouse movements and keystrokes.Once you’re done with your recording, it takes these still images into its editor and composes them with animation of the recorded mouse and keyboard input. This allows you to very easily edit your mouse movements or even clean up and rerecord what you didn’t do correctly, etc. Also, and most notably, the interface allows you to add all sorts sorts of accents: balloons, notes, annotations, menus, audio, etc etc.

Very nice program, highly recommend.