For Creating Derivatives

From UA Libraries Digital Services Planning and Documentation
Revision as of 09:33, 19 November 2009 by Jlderidder (Talk | contribs)

Jump to: navigation, search

After content has been moved to the long term archive, we need online derivatives for web access in a directory structure that mirrors the archive.

The following script runs through the archive, looking for tiff and wave files, and transcripts.

    1. Transcripts are simply copied to the web-accessible directory, placed under a Transcripts directory at the level to which it applies.
    2. ImageMagick ( )is used to create 3 image derivatives:
      1. a thumbnail, where the longest size is 128 pixels (file ends in _128.jpg)
      2. a mid-sized image (the default for delivery), where the longest side is 512 pixels (file ends in _512.jpg)
      3. a large image, where the longest side is 2048 pixels (file ends in _2048)
    3. LAME ( )is used to create an mp3 from each wave file

The command used with ImageMagick is of this form (this for the 2048 size):

 convert [OLDFILE] -strip -density 96 -resample 96x96  -resize 2048x2048 -filter Cubic -quiet [NEWFILE]

The command used with LAME is of this form:

 lame [OLDFILE] [NEWFILE] -V4 --noreplaygain -S

Here's the perl script: File:Copychange.txt

Personal tools