Copy mp3 files from cd to pen drive through vcd

Yesterday, I was playing songs from my pen drive into vcd. I had never seen such thing. First I had plugged in my pen drive to vcd, “Reading USB…”. Songs were playing, suddenly I show a message on TV screen – “Copying file…”. I was surprised. The song was copied to pen drive from CD. I could not understand, how it was possible. After hard work, I find the key that was used for copy to pen drive from cd. The key was ‘subtitle’. The subtitle key in the remote, is use to copy the mp3 to your pen drive from cd.
First of all, insert pen drive into your vcd, then insert mp3 cd. Select the song, and press subtitle button. Message will display – USB Ready… Copying file… Try it !