Modified

#!/bin/bash

if [ -z "$1" ]; then echo "No URL!" ; exit ; fi

url=$1
# added shift below, amphi added ;-)
shift

# the youtube.sh - original
# echo \"http://www.youtube.com/get_video?video_id=`wget -q -O - $url | grep fullscreenUrl | awk
# -F'video_id=' '{ print $2 }' | sed -e 's/ /_/g' | tr -d \'\; `\" | xargs mplayer -

# Modified for -dumpstream
# add the extra [-options] and replace '-' with '$'
echo \"http://www.youtube.com/get_video?video_id=`wget -q -O - $url | grep fullscreenUrl | awk -F'video_id=' '{
 print $2 }' | sed -e 's/ /_/g' | tr -d \'\; `\" | xargs mplayer -dumpstream -dumpfile /tmp/filename.dump