Asterisk dialplan: videoapplication support

Hi all,

I have found here asterisk.org/doxygen/asteris … index.html that the applications of dial plan that support video are (record, voicemail, echo). But I don’t understand if the applications work…I have read Asterisk the future of telephony book also, but there is not new information.
Where can i find more detailed information about it?

Thank in advance