app_swift - A Cepstral Swift TTS engine interface

  Copyright (C) 2006-2012 - Darren Sessions
  Portions Copyright (C) 2012, Cepstral LLC.
  Portions Copyright (C) 2013-2016 - Jeremy Kister

 
  All rights reserved.


  Bug reports, comments, or otherwise can be 
  directed to me at [email protected]. I 
  welcome any feedback or questions.

  _____________________________________________________

  Visit me on the web, at http://www.darrensessions.com
  _____________________________________________________

  http://github.com/dmsessions/app_swift
  http://www.twitter.com/darrensessions
  http://www.linkedin.com/in/dsessions
  https://plus.google.com/100445788291194233908

  ---
  This program is free software, distributed under the terms of
  the GNU General Public License Version 2. Read the LICENSE
  file for details.
  ---


  Synopsis:

        Provides a direct interface into the Cepstral
        text-to-speech engine for Asterisk eliminating
        the need to write audio output files to the 
        filesystem and then stream them back out.

        Also provides multi-digit dtmf recognition with
        a max digits and a wait-for-digit timer very 
        simular to the AGI 'get data' command.

  Requirements: 

        - Asterisk development header files
        - Cepstral Swift Text-to-Speech engine (version 5 or 6)

  Configuration: 
                
        - Check that the swift libraries are in your ld path  

        ```
        grep 'swift' /etc/ld.so.conf
        ```

        - The following alsa and oss libraries are needed for best compatibility:  

        ```
        # rhel-based os
        yum install -y alsa-lib alsa-lib-devel alsa-utils alsa-plugins-oss
        # debian-based os
        apt install -y libasound2 libasound2-dev alsa-base alsa-utils alsa-oss
        ```

        - Check that the appropriate channel driver is configured / loaded:  

        In <your asterisk path>/modules.conf uncomment EITHER:
        
        `;noload => chan_alsa.so` or `;noload => chan_oss.so`

        Load the module if not loaded:  

        ```
        asterisk -x 'module show like <your channel driver>'
        asterisk -x 'module load <your channel driver>'
        ```

        - On some distributions you made need to copy asterisk.h to /usr/include

  Installation:  

        ./configure [options]
        make
        make install (as root)
        make reload (as root)

  Usage:        

        Type "core show application swift" at the Asterisk CLI prompt.

        in extensions.conf:
        exten => s,1,Answer
        exten => s,n,Swift(This is cepstral talking in the default voice from swift.conf)
        exten => s,n,Set(SWIFT_VOICE=Callie-8kHz)
        exten => s,n,Swift(This is cepstral talking in the Callie voice)
        exten => s,n,Swift(Please enter three digits,5000,3)
        exten => s,n,Swift(You entered ${SWIFT_DTMF}.  Goodbye)
        exten => s,n,Hangup