Internet Archive News

updates about archive.org

improved h.264 derivatives!

We have thoroughly tested a newer and simpler way to create h.264 derivatives!

Changes you’ll notice:

  • More pixels!  previously 320 x 240    goes to 640 x 480 pixels
  • Slightly higher video bitrate — from about 512kb/s   to   about  700kb/s bitrate
  • Switching from mp4creator container maker to ffmpeg container + qt-faststart
  • Less back-end commands to make high-quality derivative

Nice things about this derivative (similar to prior derivative):

  • Plays in adobe flash plugin
  • Plays on all versions of iphone and ipad
  • Starts quickly, nearly instant seeking even to unbuffered areas of the video

Here’s a sample of how we do it with just 3 simple commands.  (You’d wanna adjust “-r” argument appropriately to your video’s frames-per-second).

ffmpeg -deinterlace -y -i 'camels.avi' -vcodec libx264 -fpre libx264-IA.ffpreset -vf scale=640:480 -r 20 -threads 2 -map_meta_data -1:0 -pass 1 -an tmp.mp4


ffmpeg -deinterlace -y -i 'camels.avi' -vcodec libx264 -fpre libx264-IA.ffpreset -vf scale=640:480 -r 20 -threads 2 -map_meta_data -1:0 -pass 2 -acodec aac -strict experimental -ab 128k -ac 2 -ar 44100 -metadata title='Camels at a Zoo - http://www.archive.org/details/camels' -metadata year='2004' -metadata comment=license:'http://creativecommons.org/licenses/by-nc/3.0/' tmp.mp4

qt-faststart tmp.mp4 'camels.mp4'

our preset file:
http://www.archive.org/~tracey/downloads/libx264-IA.ffpreset

 

For the adventurous out there, you can create this same setup by building ffmpeg on mac, linux, or windows.  Linux is easy, but personally, I’m a mac gal.  So here’s some ffmpeg build tips on the mac.

Happy viewing!

 

Originally posted on The Internet Archive Blog by traceypooh.
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Written by internetarchive

June 4, 2011 at 8:49 pm

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