Edit page blog/2009/11

diff --git a/blog/2009/11 b/blog/2009/11
index 85ee3f40f365c2bed21ee4ca05e76b7797fa5d93..4ecc957c33ccf3d00236ace7b7ad8032cb709ab9 100644 (file)
--- a/blog/2009/11
+++ b/blog/2009/11
@@ -18,3 +18,40 @@ If your browser sucks at HTML5, you can directly download the video files, avail
 || [[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.