If you plan to use that site on a public channel where people can convert stuff they found on Youtube or whatever, then you should register for at least a Silver account, cos the free one has the following limitations:
- maximum conversions within 24 hours: 30
- maximum upload size per file: 100 Megabyte
- maximum 10 downloads per file within one day. After one day, the converted file is deleted.
But if you plan to use it for your own limited use then a free one will do fine. I'll have a look on their API later on.
If you got your own Debian powered PC then you can do the conversion on it, just pick one of the methods described this or this.
Once the game is over, the king and the pawn go back in the same box.
a small exec should be ok, then ftp for uploading it (depending on the configuration of the server it can be possible to dl it directly to a htdocs folder).
Can work
Edit: no, the scripts only downloads the flv file. So it have to be converted to mp3 after that.