Budhajeewa's Blog

“A screencast is a digital recording of computer screen output, also known as a video screen capture, often containing audio narration. Although the term screencast dates from 2004, products such as Lotus ScreenCam were used as early as 1994. Early products produced large files and had limited editing features. More recent products support more compact file formats such as Adobe Flash and have more sophisticated editing features allowing changes in sequence, mouse movement, and audio.

Just as a screenshot is a picture of a user’s screen, a screencast is essentially a movie of the changes over time that a user sees on his monitor.”

Says Wikipedia, in it’s article on Screencast.

Just as the title suggests, I am going to write a step-by-step guide about screencasting on Ubuntu, in case I forget in the future!

Lets begin.

What you need:

I’ll not be explaining for what the items listed are needed, you’ll find out the uses of them later in this post.

• gtk-recordMyDesktop.
• ffmpeg
• PiTiVi
• sun-java6-jre and sun-java6-plugin
• Mozilla Firefox

How to do:

• Use gtk-recordMyDesktop and do your recording and get the output file, which is in OGV fornat. Before begin recording, click “Advanced” and goto “Performance” tab in resulting dialog-box. Set values as below:
  • Frames Per Second: 4 (Else, you’ll see video is faster than voice! Must be a bug!)
  • Encode On the Fly: ☑ (You don’t need to wait until that progress-bar completes, after clicking “Stop” recording. Tis don’t increase CPU usage!)
  • Zero Compression: ☑ (Decreases CPU usage.)
  • Quick Subsampling: ☑ (Decreases CPU usage, for the cost of blurred colors in videos.)
• IMPORTANT! Be sure to finish the video around 9 minutes, as YouTube only allows videos upto 10 minutes! If you got more to show, split it into parts.
• Get your OGV file into a new project of PiTiVi – Ubuntu’s default video editor – and edit it as you wish.
• Click “Render Project” and select a destination for the output file within the resulting dialog-box. IMPORTANT! Then click “Modify” and set video and audio quality as you wish (you’r choice will affect file size and video quality).Be sure to select following under “Export to” (Both the codecs and the container are FOSS, we are fully legal, fully awesome!),
  • Container: Ogg muxer [oggmux] (Remember that we got a OGV output from gtk-recordMyDesktop? Better keeping the same format here without converting to another.)
  • Audio Codec: Vorbis audio encoder [vorbisenc]
  • Video Codec: Theora video encoder [theoraenc]
• Rendering will take a little long time to complete, resulting another OGV file.
• IMPORTANT! Although YouTube allows to upload OGV files, it don’t understand them! OGV files become useless when uploaded to YouTube. So, we got to convert it to another format. Use ffmpeg to convert it. FLV, MP4 or AVI in VGA video size would do.
• Open Mozilla Firefox (Yes! Mozilla Firefox only, non other. The Java plugin which we are about to use, have some problems in Google Chrome!), Goto YouTube and click “Upload”. NO NO STOP! DO NOT start uploading here, click “Try now” under “Advanced Video Upload” and do your upload there (The Java plugin which I told you to install, will be put into use here.). Wait till the upload completes and you are done. Share your screencast with friends and enjoy!