Files
asterisk/contrib
Kevin Harwell 93ac45d3bd res_pjsip: Add option to force G.726 to be treated as AAL2 packed.
Some phones send g.726 audio packed for AAL2, which differs from what is
recommended by RFC 3351. If Asterisk receives audio formatted as such when
negotiating g.726 then it sounds a bit distorted. Added an option to
res_pjsip_endpoint that allows g.726 negotiated audio to be treated as g.726
AAL2 packed.

ASTERISK-25158 #close
Reported by: Steve Pitts

Change-Id: Ie7e21f75493d7fe53e75e12c971e72f5afa33615
2015-06-15 12:40:03 -05:00
..

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 &