Tag Archives: firefox 3.1

Fast and reliable way to encode Theora Ogg videos using ffmpeg, libtheora, and liboggz

archive.org has started to make theora derivatives for movie files, where we create an Ogg Theora video format output for each movie file. after trying a bunch of tools over a good corpus of wide-ranging videos, i found a neat way to make the Archive derivatives.

High Level:

  • use ffmpeg to turn any video to “rawvideo”.
  • pipe its output to *another* ffmpeg to turn the video to “yuv4mpegpipe”.
  • pipe its output to the libtheora tool.
  • for videos with audio, ffmpeg create a vorbis audio .ogg file.
  • add tasty metadata (with liboggz utils).
  • combine the video and audio ogg files to an .ogv output!

Detailed example:

  • ffmpeg -an -deinterlace -s 400×300 -r 20.00 -i CapeCodMarsh.avi -vcodec rawvideo -pix_fmt yuv420p -f rawvideo – |  ffmpeg -an -f rawvideo -s 400×300 -r 20.00 -i – -f yuv4mpegpipe – |  libtheora-1.0/lt-encoder_example –video-rate-target 512k – -o tmp.ogv
  • ffmpeg -y -i CapeCodMarsh.avi -vn -acodec libvorbis -ac 2 -ab 128k -ar 44100 audio.ogg
  • oggz-comment audio.ogg -o audio2.ogg TITLE=”Cape Cod Marsh” ARTIST=”Tracey Jaquith” LICENSE=”http://creativecommons.org/licenses/publicdomain/” DATE=”2004″ ORGANIZATION=”Dumb Bunny Productions” LOCATION=http://www.archive.org/details/CapeCodMarsh
  • oggzmerge tmp.ogv audio2.ogg -o CapeCodMarsh.ogv


  • Why the double pipe above? Some videos could not go directly to yuv4mpegpipe format such that libtheora (or ffmpeg2theora) would work all the time.
  • We do the vorbis audio outside of libtheora (or ffmpeg2theora) to avoid any issues with Audio/Video sync.
  • We convert to yuv420p in the rawvideo step because ffmpeg2theora has (i think) some known issues of not handling all yuv422 video inputs (i found at least a few videos that did this).
  • We add the metadata to the audio vorbis ogg because adding it to the video ogv file wound up making the first video frame not a keyframe (!)

So this will end up working in Firefox 3.1 and greater — the new HTML “video” tag:

<video controls=”true” autoplay=”true” src=”http://www.archive.org/download/commute/commute.ogv”> for firefox betans </video>

This technique above worked nicely across a wide range of source and “trashy” 46 videos that I use for QA before making live a new way to derive our videos at archive.org.

-tracey jaquith