Files
asterisk/contrib
Mark Michelson da17dc4d75 Alembic: Add PJSIP global keep_alive_interval.
The keep_alive_interval option was added about a year ago, but no
alembic revision was created to add the appropriate column to the
database.

This commit fixes the problem and adds the column. This was discovered
by running the testsuite with automatic conversion to realtime enabled.

Change-Id: If3ef92a7c4f4844d08f8aae170d2178aec5c4c1a
2015-12-16 11:25:13 -06:00
..

app_festival is an application that allows one to send text-to-speech commands
to a background festival server, and to obtain the resulting waveform which
gets sent down to the respective channel. app_festival also employs a waveform 
cache, so invariant text-to-speech strings ("Please press 1 for instructions") 
do not need to be dynamically generated all the time. 

You need : 

1) festival, patched to produce 8khz waveforms on output. Patch for Festival
1.4.2 RELEASE are included. The patch adds a new command to festival 
(asterisk_tts). 

It is possible to run Festival without patches in the source-code. Just
add this to your /etc/festival.scm or /usr/share/festival/festival/scm:

    (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)))

[See the comment with subject "Using Debian
 festival >= 1.4.3-15 (no recompiling needed!)" on
 http://www.voip-info.org/wiki-Asterisk+festival+installation for the
 original mentioning of it]

2) You may wish to obtain and install the asterisk-perl
module by James Golovich <james@gnuinter.net>, from 
either CPAN, or his site: http://asterisk.gnuinter.net,
as this contains a good example of how variable text
can be tts'd via asterisk, namely the examples/tts-*.agi
files there. It has been noted that the current expression
evaluation capabilities of asterisk are not best suited
for the generation and manipulation of text. AGI scripting
can be ideal for these sorts of needs. For simpler usage,
fixed, pre-recorded messages may be more amenable for your
purposes.

3) Before running asterisk, you have to run festival-server with a command 
like : 

/usr/local/festival/bin/festival --server > /dev/null 2>&1 &