== Thu, Nov 26: The Day of Tofurky == {{ pictures/home/acetarium/2009-tofurky2/00122.jpeg | maxwidth=640}} {{ pictures/home/acetarium/2009-tofurky/00022.jpg | maxwidth=640}} All photos: * [[pictures/home/acetarium//2009-tofurky]] * [[pictures/home/acetarium//2009-tofurky2]] == Wed, Nov 25: Home, sweet home == {{http://i33.photobucket.com/albums/d52/mochifish/IMG_1566.jpg}} == Exploring Julia in 4 dimensions == The discovery of the [[http://www.skytopia.com/project/fractal/mandelbulb.html | Mandelbulb]] awekened my old passion for fractals. So I took the time to re-encode my old rendering of the [[http://en.wikipedia.org/wiki/Quaternion | Quaternion]] [[http://en.wikipedia.org/wiki/Julia_set | Julia set]] done with POV-Ray. Behold: {{pictures/julia4D/julia4D-640x360.ogv | Quaternion Julia 4D fractal (640x360 @ 1200Kbit/s, Ogg Theora encoded)}} The sound track is [[http://lite.modarchive.org/index.php?request=view_by_moduleid&query=59288 | UranChrome]], an old-skool Amiga SoundTracker module composed by TorbJ0rn in 1989. === Downloads === If your browser sucks at HTML5, you can directly download the video files, available in several formats: || **Filename** || **Resolution**|| **Birate** ||**Video**||**Audio**||**Size**|| || [[pictures/julia4D/julia4D.ogv | julia4D.ogv (Ogg)]] || 1280x720 || 6000Kbit/s || Theora || Vorbis || 60MB || || [[pictures/julia4D/julia4D-640x360.ogv | julia4D-640x360.ogv (Ogg)]] || 640x320 || 1200Kbit/s || Theora || Vorbis || 13MB || || [[pictures/julia4D/julia4D.avi | julia4D .avi]] || 1280x720 || 6000Kbit/s || H.264 || - || 60MB || || [[pictures/julia4D/julia4D-640x360.avi | julia4D-640x360.avi]] || 640x360 || 1200kbit/s || H.264 || - || 12MB || === Rendering notes === It took about 2 weeks of computation on a dual-core machine to render the 2048 high resolution frames contained in 82 seconds of video. My previous renderings at lower resolution and lower iteration count were much faster. A The high iteration count actually makes the fractal surface a little too polverized to appreciate. Adding transparency and gradients is another bad idea as it complicates things even more. If I find the time and motivation to re-render the animation, I'll look for better balance. In case someone wants to experiment, these are the [[pictures/julia4D/julia4D.pov | scene source]] and [[pictures/julia4D/julia4D.ini | ini file]] I used. === Video encoding notes === The files were encoded from a sequence of PNG frames generated by POV-Ray, using **ffmpeg** and **mencoder**: {{{ # hires mpeg4 please mencoder 'mf://julia4D????.png' -mf fps=25 \ -ovc x264 -x264encopts bitrate=6000:pass=1:threads=2 -o julia4D.avi # lores mpeg4 please mencoder 'mf://julia4D????.png' -mf fps=25 -vf scale=640:360 \ -ovc x264 -x264encopts bitrate=1200:pass=1:threads=2 -o julia4D-640x360.avi # hires theora please ffmpeg -f image2 -i julia4D%04d.png \ -threads 2 -vb 6000k -vcodec libtheora -acodec libvorbis -f ogg julia4D.ogv \ -i UranChrome-fx-short.wav -acodec libvorbis -ab 96k -newaudio # lores theora please ffmpeg -f image2 -i julia4D%04d.png \ -threads 2 -s 640x360 -vb 1200k -vcodec libtheora -f ogg julia4D-640x360.ogv \ -i UranChrome-fx-short.wav -acodec libvorbis -ab 96k -newaudio }}} This is the software I have used: {{{ MEncoder SVN-r29800-4.4.2 (C) 2000-2009 MPlayer Team FFmpeg version SVN-r20372, Copyright (c) 2000-2009 Fabrice Bellard, et al. libtheora-1.1.0 libvorbis-1.2.0 x264-libs-0.26.20091026 }}} The quality of the low-res Theora stream is noticeably lower than the corresponding low-res H.264. I don't know why.