Using cepstral webbased voice synthesized demo to generate voice prompts for asterisk on the fly

Prerequisites

Time
Asterisk
Internet Connectivity
PHP (in this example we use version 5.0.4)

Introduction

Why?

I personaly wanted to be able to generate occasional voice prompts dynamicaly without the need for recording on my home PC and uploading via FTP and then moving to the correct directory on my dedicated server.

Getting Started

mkdir /etc/asterisk/php/
cd /etc/asterisk/php/
nano speech.php

Paste into nano

<?php
$args = $_SERVER["argv"];
$i = 0;
while ($i<sizeof($args))
{
if ($i>0)
{
$arg[$i-2] = $args[$i];
}
$i++;
}
$text=urlencode(implode(" ",$arg));

system(‘rm /var/lib/asterisk/sounds/tikka.gsm’);
system(‘/usr/bin/wget -O /tmp/tikka.wav "http://qs913.pair.com/cepstral/demos/demo.cgi/cepstral.wav?content=’.$text.’&voice=Lawrence&rate=160&pitch=1&effect=none&submit=Synthesize+the+Text"’);
?>

The above code will take commandline parameters passed to it from asterisk when we call it from extentions.conf.

Press CTRL + X to close nano, it will ask if you wish to save press y for yes and then press enter to save our file with the name speech.php.

Another file that we will be creating is time.php, this is based on the same file above but generates a fun time announcement. (UK Residents will recognise this hopefuly ;))

nano time.php

Paste into nano

<?php
$today = date("h:i:s");
$text = "At the third stroke, the time sponsored by accurist will be, ";
$text .= date("’h’") . "" . date("’i’") . " and " . date("’s’") . " seconds BEEP BEEP BEEP";
system(‘rm /var/lib/asterisk/sounds/time.gsm’);
system(‘/usr/bin/wget -O /tmp/time.wav "http://qs913.pair.com/cepstral/demos/demo.cgi/cepstral.wav?content=’.$text.’&voice=Lawrence&rate=160&pitch=1&effect=none&submit=Synthesize+the+Text"’);
?>

cd ..
nano extentions.conf

Paste into extentions.conf

[inbound]
exten => _X.,1,Answer
exten => _X.,2,System(php -q /etc/asterisk/php/speech.php Please Wait.) ; tells caller to "please wait"
exten => _X.,3,System(sox /tmp/tikka.wav -r 8000 -c 1 -s -w /var/lib/asterisk/sounds/tikka.gsm resample -ql) ; using sox (sox.sourceforge.net) encode our new wave file downloaded from cepstral website to a format more comfortable to asterisk for sending to our caller.
exten => _X.,4,Playback(tikka) ; playback the file tikka(.gsm) contained in /var/lib/asterisk/sounds/
exten => _X.,5,Wait,1
exten => _X.,6,System(php -q /etc/asterisk/php/time.php) ; this is our time generation script
exten => _X.,7,System(sox /tmp/time.wav -r 8000 -c 1 -s -w /var/lib/asterisk/sounds/time.gsm resample -ql)
exten => _X.,8,Wait,1
exten => _X.,9,Playback(time)
exten => _X.,10,Wait,5

Breakdown of PHP Script

<?php //begin php code
$text = "At the third stroke, the time sponsored by accurist will be, "; // set our intro message
$text .= date("’h’") . "" . date("’i’") . " and " . date("’s’") . " seconds BEEP BEEP BEEP"; // get hour, minute and seconds and complete our message sentance.
system(‘rm /var/lib/asterisk/sounds/time.gsm’); // delete the old time.gsm file
system(‘/usr/bin/wget -O /tmp/time.wav "http://qs913.pair.com/cepstral/demos/demo.cgi/cepstral.wav?content=’.$text.’&voice=Lawrence&rate=160&pitch=1&effect=none&submit=Synthesize+the+Text"’); // using wget, grab the wave file generated by the cepstral demo website and save it to /tmp/ with the filename time.wav
?> // close script tag

Save your new time.php script, reload extentions.conf in asterisk.

Ring your asterisk box.. enjoy!

For more scripts in the future checkout my website http://www.tikka-d.co.uk (currently no asterisk information however).