Page 332 - Asterisk™: The Future of Telephony

Getting Festival Set Up and Ready for Asterisk
There are currently two ways to use Festival with Asterisk. The first (and easiest) meth-
od—without having to patch and recompile Festival—is to add the following text to
Festival’s configuration file (festival.scm, usually located in /etc/ or /usr/share/festival/):

(define (tts_textasterisk string mode)
"(tts_textasterisk STRING MODE)
Apply tts to STRING. This function is specifically designed for use in
server mode so a single function call may synthesize the string. This
function name may be added to the server safe functions."
(let ((wholeutt (utt.synth (eval (list 'Utterance 'Text string)))))
(utt.wave.resample wholeutt 8000)
(utt.wave.rescale wholeutt 5)
(utt.send.wave.client wholeutt)))
You may place this text anywhere in the file, as long as it is not between any other
parentheses.
The second (and more traditional) way is to compile Festival with an Asterisk-specific
patch (located in the contrib/ directory of the Asterisk source).
Information on both of these methods is contained in the README.festival file, located
in the contrib/ directory of the Asterisk source.
For either method, you’ll need to modify the Festival access list in the festival.scm file.
Simply search for the word “localhost” and replace it with the fully qualified domain
name of your server.
Both of these methods set up Festival to be able to correctly communicate with Asterisk.
After setting up Festival, you should start the Festival server. You can then call the
Festival() application from within your dialplan.

Configuring Asterisk for Festival

The Asterisk configuration file that deals with Festival is aptly called festival.conf. Inside
this file, you specify the hostname and port of your Festival server, as well some settings
for the caching of Festival speech. For most installations (if you’re going to run Festival
on your Asterisk server), the defaults will work just fine.

Starting the Festival Server
To start the Festival server for debugging purposes, simply run festival with the
--server argument, like this:
[root@asterisk ~]# festival --server

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