WebM encoding CC’s videos

akozak, December 3rd, 2010

I was recently tasked with encoding all of CC’s videos into WebM, a new open video container format.

I started out by creating a table of all of the videos and target quality. Then, I started to track down the highest quality version of each video I could find.

At first I had high hopes of using ffmpeg (with libvpx support) wrapped in a bash script to batch process all of the videos into .webm. Although there are some decent directions to re-compiling ffmpeg to enable webm, I ran into trouble (some sort of version conflict) and wasn’t able to complete the process.

So after searching around, I found a few promising leads on the WebM tools page.

Our friends at Miro have come out with Miro Video Converter, which is a useful-looking tool that promises a simple way to encode video for mobile devices and the web. It purports to support webm, but sadly I wasn’t able to test it as they don’t currently develop a version for Linux (only Windows and OSX).

Next I tried installed the Fireogg extension into Firefox and tested the process by converting one small .mov file into .webm. I was surprised how well it worked, although as far as I could tell it lacked a method to batch-process or queue files (or at least that functionality isn’t within scope for its purpose). It also took an unreasonably long time to transcode the video, so my search continued.

With Arista Transcoder, I found a Linux application that seemed to work. In Ubuntu, setup was as simple as extracting the archive and running python install --install-layout=deb (provided you have python installed). The Web Browser (Advanced) preset gave me the ability to queue up and transcode the videos into 360p, 480p, and 720p .webm with reasonable transcoding times.

One minor hurdle was to encode the videos into 240p WebM, a resolution not included in the Web Browser (Advanced) preset package. To accomplish that, I modified the json preset file to include 240p into webm. You can download my modified version of the json file in the preset here. My only modification comes at the end. You should be able to just copy my version into ~/.arista/presets and replace the original if it exists.

When we start to embed the files on, I plan on following the instructions in the Dive Into HTML5 Video chapter.

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Semantic Videowiki

ml, July 6th, 2007

Don’t get too excited by the post title, just pointing out a nice 5 minute video (mp4) from Oxford Geek Nights explaining the basic features of Semantic Mediawiki. Thierry is experimenting with SMW features on the CC Wiki.

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