X-Git-Url: https://codewiz.org/gitweb?p=wiki.git;a=blobdiff_plain;f=blog%2F2009%2F11;h=60f262905f6689d871e13e3e9f9e91a1e307db06;hp=2e83f00bbb7c4f963e3ecab313078b6813a09a03;hb=c4ea091659fe8148d1e17c3e5e71dfc98e6db4f0;hpb=6544187d6d72e23a45fb1fc3a73ff8d87f2b0eca

diff --git a/blog/2009/11 b/blog/2009/11
index 2e83f00..60f2629 100644
--- a/blog/2009/11
+++ b/blog/2009/11
@@ -1,4 +1,4 @@
-== Fractal passion ==
+== Exploring Julia in 4 dimensions ==
 
 The discovery of the [[http://www.skytopia.com/project/fractal/mandelbulb.html | Mandelbulb]] awekened my old
 passion for fractals.
@@ -13,5 +13,45 @@ an old-skool Amiga SoundTracker module composed by TorbJ0rn in 1989.
 
 If your browser sucks at HTML5, you can directly download the video files, available in several formats:
 
-|| [[pictures/julia4D/julia4D.ogv | 1280x720 @ 6000Kbit/s OGG Theora]] [60MB]                 || [[pictures/julia4D/julia4D-640x360.ogv | 640x320 @ 1200Kbit/s, OGG Theora]] [13MB] ||
-|| [[pictures/julia4D/julia4D.avi | 1280x720 @ 6000Kbit/s AVI MPEG4 ]] [60MB] (no soundtrack) || [[pictures/julia4D/julia4D-640x360.avi | 640x360 @ 1200kbit/s AVI MPEG4]] [12MB] (no soundtrack) ||
+|| **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 ||
+
+=== 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.