The PERL script below needs for the line which reads:

!/usr/bin/perl 

to instead read:

#!/usr/bin/perl


If your a newbie and the script did not work for you this will fix it.


Additionally if you think the speech sounds funny (slow, slurred) and you would like for the Cepstral swift engine to speak normally for you then modify the line which reads:

  my $execf=$t2wp."swift -f $sounddir/say-text-$hash.txt -p audio/channels=1,cst/f0_shift=.8,speech/rate=120,audio/sampling-rate=8000,audio/deadair=2 -o $wavefile"; 

to instead read as such:

  my $execf=$t2wp."swift -f $sounddir/say-text-$hash.txt -p audio/channels=1,audio/volume=70,audio/sampling-rate=8000,audio/deadair=2 -o $wavefile";


If you need details of the parameters such as "speech/rate" or "audio/deadair" then launch the Cepstral swift engine with the following command line options:

  swift --params

I purchased (registered) one voice from cepstral and wanted to get it working, it was actually quite simple and worked well.
create a file called cepstral.agi containing the following (which is just a modified version of festival-script) and you can modify the voice parameters ( I had to increase my gain ) by creating a default.sfx in the /swift/voices/VOICENAME below is the exten.conf calling it as well. :

= CEPSTRAL.AGI ==

1. !/usr/bin/perl

use Asterisk::AGI;
use File::Basename;
require Data::UUID;

$AGI = new Asterisk::AGI;

my $ug = new Data::UUID;

my $timestamp = gmtime;
my %input = $AGI->ReadParse();
my ($text)=@ARGV;
my $hash = $ug->create_str;
my $sounddir = "/var/lib/asterisk/sounds/tts";
my $wavefile = "$sounddir/"."tts-$hash.wav";
my $t2wp= "/opt/swift/bin/";

unless (-f $wavefile) {
       open(fileOUT, ">$sounddir"."/say-text-$hash.txt");
       print fileOUT "$text";
       close(fileOUT);
       my $execf=$t2wp."swift -f $sounddir/say-text-$hash.txt -p audio/channels=1,cst/f0_shift=.8,speech/rate=120,audio/sampling-rate=8000,audio/deadair=2 -o $wavefile";
       system($execf);
       unlink($sounddir."/say-text-$hash.txt");
}

$AGI->stream_file('tts/'.basename($wavefile,".wav"));
===
DEFAULT.SFX

1. Volume

GAIN 1

1. Chorus
2. CHO 0.5 1.0 0.3 1 1 4

==
Extenstions.conf
exten => *23,1,Wait(2) ; So the text does read off before they put the phone to their ear.
exten => *23,2,AGI(cepstral.pl|PUT THE TEXT TO READ HERE)
==

Hope this helps

== Spawn extension (from-internal, h, 1) exited non-zero on 'Zap/3-1'
   — Hungup 'Zap/3-1'
   — Starting simple switch on 'Zap/3-1'
   — Executing Answer("Zap/3-1", "") in new stack
   — Executing DateTime("Zap/3-1", "") in new stack
   — Playing 'digits/day-4' (language 'en')
   — Playing 'digits/mon-2' (language 'en')
   — Playing 'digits/h-17' (language 'en')
   — Playing 'digits/2' (language 'en')
   — Playing 'digits/thousand' (language 'en')
   — Playing 'digits/5' (language 'en')
   — Playing 'digits/at' (language 'en')
   — Playing 'digits/4' (language 'en')
   — Playing 'digits/40' (language 'en')
   — Playing 'digits/8' (language 'en')
   — Playing 'digits/p-m' (language 'en')
   — Executing AGI("Zap/3-1", "swift.agi|Hello World") in new stack
   — Launched AGI Script /var/lib/asterisk/agi-bin/swift.agi
   — AGI Script swift.agi completed, returning 0
   — Executing Hangup("Zap/3-1", "") in new stack
 == Spawn extension (from-internal, 1234, 4) exited non-zero on 'Zap/3-1'
   — Executing Macro("Zap/3-1", "hangupcall") in new stack
   — Executing ResetCDR("Zap/3-1", "w") in new stack
   — Executing NoCDR("Zap/3-1", "") in new stack
   — Executing Wait("Zap/3-1", "5") in new stack
   — Executing Hangup("Zap/3-1", "") in new stack
 == Spawn extension (macro-hangupcall, s, 4) exited non-zero on 'Zap/3-1' in macro 'hangupcall'
 == Spawn extension (from-internal, h, 1) exited non-zero on 'Zap/3-1'
   — Hungup 'Zap/3-1'

My swift install is located in /opt/swift/bin

it works from the command line just fine.

I also have festival installed and it works both from the command line and through asterisk.

swift.agi has been cut and pasted as in into /va/lib/asterisk/agi-bin

My extension.conf file has the following context:
exten => 1234,1,Answer
exten => 1234,2,DateTime()
exten => 1234,3,AGI(swift.agi|Hello World)
exten => 1234,4,Hangup

• I have tried with and without quotes wrapping the text.

The date and time works but swift.agi doesn't make a sound.

What am I doing wrong. I changed the line in swift.agi to point correctly to my swift install directory but it still doesn't work.

Also I copied your example after I went into edit mode so I got the correct comments and everything.