Learning how to create Linux screencasts has been the most frustrating technical challenge that I have tackled for a very long time. I should have been worried when a search for “Linux video editing” returned, as its top hit, a bare and completely unstyled web page from 2002 which concludes that “video editing on Linux hasn’t really arrived yet.”

My efforts were, in the end, successful, and you can see the result — my first two screencasts — in my previous blog entry, which I posted earlier this week.

In the hope that my toil can benefit others, let me outline the details of the process that I have worked out for creating, editing, and posting Linux screencasts. For the impatient, here are the three most important things I learned:

• Linux tools have great difficulty keeping audio and video from gradually going out of sync over several minutes. To avoid problems, always run recordmydesktop with its “on-the-fly encoding” option, and never let “ffmpeg” anywhere near your audio! This not only means that you have to use “mencoder” instead when converting between video formats, but even within mencoder you must avoid the “lavc” audio module, since its code seems to have the same problems.
• Do not attempt to directly edit the resulting Ogg/Theora video! Instead, convert first to the Digial Video (DV) format, and perform your editing there. Be prepared for the fact that DV files are enormous, and that DV pixels are not square.
• Finally, convert to something like AVI for submission to Google Video. Avoid submitting a raw Ogg/Theora file, since even though Google can decode it, their decoders will waste valuable screen space by placing an empty border around the result.

For those interested in more details, I have more to share. Keep reading!

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After several frustrating weeks learning how to create, edit, and publish a screencast under Linux (about which I will write a separate post), I have now published screencasts of both presentations that I gave at the PyAtl meetup in January. I opened with a talk about the import statement, and where Python packages lived before egg files were invented:

The audience seemed most interested in the last section of the talk, where I discuss three techiques for debugging problems with Python’s import statement; fast-forward to around 3:00 if you want to catch that part by itself.

Next, Jeremy Jones spoke about eggs, Noah Gift introduced virtualenv, and, finally, I got back up to talk about buildout. This was probably my own favorite among the recent presentations I have given, and it’s the one I’ve worked hardest to adapt to a competent screencast:

I have prepared a supplement to the above screencast that gives additional hints and tips about using buildout, as well as a link to the source code of the module that I use as my example.

Finally, if you’re ready to see something a little less polished — something that instead of being a screencast is actually a film of me talking in front of a live audience, and gesturing and jumping around — I filled a vacant lightning-talk slot at our February PyAtl meeting with an impromptu introduction to Kinetic Style Sheets (KSS), using an example application that was still sitting on my laptop after at a Georgia Tech developer’s luncheon earlier that week:

Now I can finally turn my attention to preparing for my upcoming talk at PyCon 2008 in Chicago! I will be talking about the basic “adapter” design pattern, and how a framework like Zope 3 can facilitate its use. Stay tuned for more information!