ra2ogg.sh

Shall高级编程

#!/bin/bash
# ra2ogg.sh: Convert streaming audio files (*.ra) to ogg.

# Uses the "mplayer" media player program:
#      http://www.mplayerhq.hu/homepage
#      Appropriate codecs may need to be installed for this script to work.
# Uses the "ogg" library and "oggenc":
#      http://www.xiph.org/


OFILEPREF=${1%%ra}      # Strip off the "ra" suffix.
OFILESUFF=wav           # Suffix for wav file.
OUTFILE="$OFILEPREF""$OFILESUFF"
E_NOARGS=65

if [ -z "$1" ]          # Must specify a filename to convert.
then
  echo "Usage: `basename $0` [filename]"
  exit $E_NOARGS
fi


##########################################################################
mplayer "$1" -ao pcm:file=$OUTFILE
oggenc "$OUTFILE"  # Correct file extension automatically added by oggenc.
##########################################################################

rm "$OUTFILE"      # Delete intermediate *.wav file.
                   # If you want to keep it, comment out above line.

exit $?

#  Note:
#  ----
#  On a Website, simply clicking on a *.ram streaming audio file
#+ usually only downloads the URL of the actual audio file, the *.ra file.
#  You can then use "wget" or something similar
#+ to download the *.ra file itself.


#  Exercises:
#  ---------
#  As is, this script converts only *.ra filenames.
#  Add flexibility by permitting use of *.ram and other filenames.
#
#  If you're really ambitious, expand the script
#+ to do automatic downloads and conversions of streaming audio files.
#  Given a URL, batch download streaming audio files (using "wget")
#+ and convert them.