Tag Archives: theora

Improved theora/ogg video derivatives!

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We’ve made our ogg video derivatives slightly better via:

  • minor bump up to “thusnelda” release
  • “upgrade” from 1-pass video encoding to 2-pass video encoding
  • direct ffmpeg creation of the video (you’ll need to re/compile ffmpeg minimally with “–enable-libtheora –enable-libvorbis” configure flags)

ffmpeg -y -i ‘camels.avi’ -q:vscale 3 -b:v 512k -vcodec libtheora -pix_fmt yuv420p -vf yadif,scale=400:300 -r 20 -threads 2 -map_metadata -1,g:0,g -pass 1 -an -f null /dev/null;

ffmpeg -y -i ‘camels.avi’ -q:vscale 3 -b:v 512k -vcodec libtheora -pix_fmt yuv420p -vf yadif,scale=400:300 -r 20 -threads 2 -map_metadata -1,g:0,g -pass 2 -map 0:0 -map 0:1 -acodec libvorbis -ac 2 -ab 128k -ar 44100 -metadata TITLE=’Camels at a Zoo’ -metadata LICENSE=’http://creativecommons.org/licenses/by-nc/3.0/’ -metadata DATE=’2004′ -metadata ORGANIZATION=’Dumb Bunny Productions’ -metadata LOCATION=http://archive.org/details/camels camels.ogv

some notes:

  • You’d want to adjust the “scale=WIDTH:HEIGHT” accordingly, as well as the “-r FRAMES-PER-SECOND” related args, to your source video.
  • I made a small patch to allow *both* bitrate target *and* quality level for theora in ffmpeg, after comparing the other popular tool “ffmpeg2theora” code with the libtheoraenc.c inside ffmpeg.  It may not be necessary, but I believe I saw *slightly* better quality coming out of theora/thusnelda ogg video.  For what it’s worth, my minor patch is here:  http://archive.org/~tracey/downloads/patches/ffmpeg-theora.patch
  • The way we compile ffmpeg (ubuntu/linux) is here.  (Alt MacOS version here )
  • (Edited post above after I removed this step) It’s *quite* odd, I realize to have ffmpeg transcode both the audio/video together, only to split/demux them back out temporarily.  However, for some videos, the “oggz-comment” step would wipe out the first video keyframe and cause unplayability in chrome (and the expected visual artifacts for things that could play it).   So, we split, comment the audio track, then re-stitch it back together.

archive.org supports the new [video] HTML tag!

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We now support the new [video] HTML tag when viewing movies from our site.

You’ll need Firefox v3.5+ (full or beta release) or Safari v4+ for us to show you a “try the new [video] tag” section under the “click to play” video area.

You can even persist a choice to always use it on our site (by us setting a cookie for you) (and you can change your mind and go back to the normal flash plugin based option).

-Tracey Jaquith


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New strategy for Internet Archive movies!

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We have rebuilt all of our nearly 200,000 videos at the archive!

[We finished this Dec 1, 2008]

Related cross-blog with OLPC.

Here is a table-based chart of which video formats will be “derived” into which formats (we are creating 4 formats per video now):

http://www.archive.org/help/derivatives.php

Improvements and Changes from our prior movies techniques:

  • We will make a new Ogg Theora (with Vorbis audio) opensource/free-based video derivative. This derivative will play natively in Firefox 3.1 release (v3.1 is due around the end of 2008).
  • We are re/making h.264 MPEG-4 derivatives. We have updated the format to work with lighttpd “mod_h264_streaming” (which allows jumping into a movie at a specified time) but in the process will be losing the ability to serve/stream this file with RTSP.  This derivative also plays in the Adobe Flash plugin and plays on iPods/iPhones.
  • We are removing older 64kb and 256kb MPEG-4 derivatives.  With “progressive download” support becoming ubiquitous, even modems and phones are doing much better with downloading larger files.
  • We are removing older .flv “Flash Video” derivatives.  Since the much better quality h.264 derivative plays in recent flash plugins (as well as many other devices and browsers), the flash video alternative is seen as less ideal.
  • We are removing older .mpg MPEG-1 derivatives.  Their usefulness has declined in recent years, especially compared to h.264 alternatives.
  • We are remaking our animated GIFs. They attempt to make 30 thumbnails from each uploaded video.  We now evenly space them across the entire video.
  • We are remaking our Thumbnails. Similar to the GIF, we are spreading them across the videos better, and making less Thumbnails for items with *many* videos.  Additionally, we are renaming the thumbnails to indicate the second position in the video they were created at.  This will allow for the next bullet item…
  • We have developed the ability to jump into videos by clicking on the thumbnail image (to go to that scene!) We are finalizing the URL / permalinks for these “jump into video” URLs and will release this live to the public as soon as we can.

-tracey jaquith

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

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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

WTFs:

  • 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