The online documentation
http://www.freepbx.org/support/documentation/module-documentation/music-on-hold/add-streaming-catagory states
“This example uses a scirpt created in /usr/sbin/ called “ast-playlinein” and it is used to control the parameters of “arecord” which is the program doing the heavy lifting here. Pointing at the script was all that was needed”
I can’t find the script ast-playlinein