IFS=$'\n'; find -type f -iname "*.mp3" | while read i; do /home/alexsmith/scripts/mp3shrink.sh "$i" & done

Be careful when using this, since it will shrink all files in background, easily overloading the CPU.

What you need is xjobs (from a package manager near you):

find -type f -iname "*.mp3" | xjobs $HOME/scripts/mp3shrink.sh

(P.S. you should use ${TMPDIR-/tmp} in place of plain old /tmp, then you can point it somewhere in the same filesystem as the music, to make the final copy stage faster - and to work with systems using e.g. pam_tmpdir)


#!/bin/bash
#
#mp3shrink - A script to resample all mp3 files in a
# directory. This script depends upon gstremar-tools
#
# It is suggested that mp3shink be placed in the
# user's private bin (~/bin).
######################################################

#clean up
if
test -e mp3_list
then
rm mp3_list
fi
if
test -e tag2.txt
then
rm tag2.txt
fi
exit


Thanks a lot for the scripts!

I found a very nice package which copies id3tags directly in an easier manner.


sudo apt-get install libid3-tools


This lib has a nice binary called id3cp, which copies all id3tags from one file to another.

Thus, the script became simpler, like this:


#!/bin/bash

echo "Shrinking $1"
tmp=$(basename "$1")
lame --silent -v --preset standard "$1" "/tmp/$tmp"
id3cp "$1" "/tmp/$tmp"
mv "/tmp/$tmp" "$1"
echo "Done shrinking $1"


Note that I modified the script to encode one file at a time, thus making it possible to process multiple files in background with something like this:


IFS=$'\n'; find -type f -iname "*.mp3" | while read i; do /home/alexsmith/scripts/mp3shrink.sh "$i" & done


Be careful when using this, since it will shrink all files in background, easily overloading the CPU.

To shrink a single file, one could just type this:


./mp3shrink.sh inputfile.mp3


After the process, inputfile.mp3 will be shrinked down. Please note that inputfile.mp3 itself will get shrinked. This may not be what you want.

Here is the modified script:

#!/bin/bash
#
#mp3shrink - A script to resample all mp3 files in a
# directory.  This script calls the cptag script which
# must also be in the user's path. cptag depends upon
# lame and mid3v2 (mid3v2 can be found in the
# python-mutagen package).
#
# It is suggested that both the mp3shink and cptag
# scripts be placed in the user's private bin (~/bin).
######################################################

# Check if resample directory exists and create it if it doesn't.
if
   test -e ./resample
then
   echo "resample directory/file already exists - delete it? (Y/n)"
   read reply
   if
     [ "$reply" != "n" ]
   then
     rm -r resample
     mkdir resample
   else
     exit
   fi
else
   mkdir resample
fi

#Copy directory structure of the music collection to encode into resample directory
find . -type d | cpio -pvdm ./resample; rm -r ./resample/resample 

# List mp3's in current directory.
find . -name \*.mp3 > mp3_list
find . -name \*.MP3 >> mp3_list

# Parse the mp3_list and replace spaces with escaped spaces.
sed -i 's: :\\ :g' mp3_list

# Resample each mp3 and write tags using the cptag script
cat mp3_list |while read song
do
   echo "$song"
   ~/bin/cptag "$song"
done

#clean up
if
   test -e mp3_list
then
   rm mp3_list
fi

if
   test -e tag2.txt
then
   rm tag2.txt
fi

exit

Hope somebody find this post useful as I did with previous comments.