Converting screencasts to Ogg Theora (.ogv)
For the Adblock Plus video Wladimir wanted a freely licensed .ogv video to accompany the YouTube format. At first I turned to my trusty ffmpeg but it seems that theora/vorbis output isn’t as good as it could be using ffmpeg. [If you want tips on ffmpeg, see my earlier converting screencasts with ffmpeg post]
A good comment on the post Fast and reliable ways to encode Theora Ogg videos pointed me at ffmpeg2theora which Just Works. I’m using v0.21 on Ubuntu, and v0.24 looks to be the most current, but v0.21 did the job fine.
At first I tried using the defaults:
ffmpeg2theora AdBlockPlus_iPhoneFinished.mov -o out.ogv
which converted the 35mb .mov to an 8mb .ogv but the video stream had some artefacts. The audio stream was far superior compared to ffmpeg’s attempts. To solve the video artefacts I asked it to use ‘quality level 8′ rather than the default 5:
ffmpeg2theora AdBlockPlus_iPhoneFinished.mov -v 8 -o out.ogv
and the 13mb output is great. I also created a 10mb .m4v iPhone version so I can demo it when on the move.
Ian produces professional screencasts (ProCasts, twitter), writes The Screencasting Handbook and blogs (IanOzsvald.com).
The Converting screencasts to Ogg Theora (.ogv) by ProCasts' Blog about Professional Screencast Production, unless otherwise expressly stated, is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England License.
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September 9th, 2009 at 9:15 pm
[...] you’re an ffmpeg user you might find some of my other tips on using ffmpeg to transcode videos to be useful (although they don’t outline the above [...]