ffmpeg wrapper. comvert mp4 to mp3 in a current dir.

mp4tomp3.sh

#!/bin/sh
 
while getopts dyh OPT
do
    case $OPT in
    "d" )
        flag_d=1
        ;;
    "y" )
        flag_y="-y"
        ;;
    "h" )
            echo "\n\n	$(basename $0)"
            echo "\n	create mp3 files from mp4 files in the current directory"
            echo "\n	usage: $(basename $0) [options]\n"
            echo "	-d	delete sorce mp4 files."
            echo "	-y	overwrite existing mp3 files when file name is the same."
            echo "	-h	show this help."
            echo "\n"
            exit 2
        ;;
    esac
done
 
ls | grep "\.mp4$"
if [ "$?" eq 1 ]; then
    echo "no mp4 files"
    exit 2
fi
 
for f in *.mp4; do ffmpeg `echo $flag_y`  -i "$f" "`echo $f | sed -e "s/.mp4/.mp3/"`"; done
 
if [ "$flag_d" ]; then
    echo "\nremoving " 
    echo `ls | grep "\.mp4$"`
    rm *.mp4
fi
if [ "$?" eq 1 ]; then
    echo "something wrong.\n"
else
    echo "done.\n"
fi