NVBackgroundDetect

Background with Fax Detection for IAX/SIP/ZAP

Including non-silence and digit detection. Search the web for the code.

Synopsis

Background a file with talk and fax detect (on IAX and SIP too)

Description

NVBackgroundDetect(filename[|options[|sildur[|mindur[|maxdur]]]])

Plays filename, waiting for interruption from fax tones (on IAX/SIP too), a digit, or non-silence. Audio is monitored in the receive direction. If digits interrupt, they must be the start of a valid extension unless the option is included to ignore. If fax is detected, it will jump to the ‘fax’ extension. If a period of non-silence is greater than ‘mindur’ ms, yet less than ‘maxdur’ ms is followed by silence at least ‘sildur’ ms then the app is aborted and processing jumps to the ‘talk’ extension. If all undetected, control will continue at the next priority.

Parameters

options:
‘n’: Attempt on-hook if unanswered (default=no)
‘x’: DTMF digits terminate without extension (default=no)
‘d’: Ignore DTMF digit detection (default=no)
‘f’: Ignore fax detection (default=no)
‘t’: Ignore talk detection (default=no)
sildur: Silence ms after mindur/maxdur before aborting (default=1000)
mindur: Minimum non-silence ms needed (default=100)
maxdur: Maximum non-silence ms allowed (default=0/forever)

Return codes

Returns -1 on hangup, and 0 on successful completion with no exit conditions.

Notes

This code is NOT included with Asterisk at this point, however it is free. To get it, search the web.

This should only work on channels that are using ULAW/ALAW.

Requirements

Asterisk development or stable

Sample Usage (extensions.conf)

[context-incoming]
; Answer and do some detection work
exten => s,1,Answer
exten => s,2,NVBackgroundDetect(welcome)
exten => s,3,Hangup

; If user presses "1", dial main line
exten => 1,1,Dial(SIP/5500)
exten => 1,2,Hangup

; If this is a fax, dial fax line
exten => fax,1,Dial(SIP/5501)
exten => fax,2,Hangup

; If user is talking, send him to Debra
exten => talk,1,Dial(SIP/5502)
exten => talk,2,Hangup

Installation

Easiest way to get up and running:

(1) Drop the code in your /usr/src/asterisk/apps directory

(2) Edit the Makefile in the apps directory. Add the following line:
APPS+=app_nv_backgrounddetect.so

(3) Go to /usr/src/asterisk and run “make”, then run “make install”

If you encounter compiler errors like:

error: struct ast_channel has no member cid

Edit app_nv_faxdetect.c and enable the CALLERID_FIELD #define statement:

define CALLERID_FIELD cid.cid_num

Comment out the other, existing definition.

(4) Start or restart Asterisk

(5) Type “show application nvbackgrounddetect” from the CLI and you should see it

Future Improvements

We are working on answering machine detection for this module.

UPDATE FOR ASTERISK 1.4.24+ USERS

Working version for Asterisk 1.4.24+

http://www.austechpartnerships.com/app_nv_1.4.2x_07052010.tar.gz

Tested with 1.4.26, 1.4.26.1, 1.4.31.

Also includes NVBackgroundDetect but was untested. Module compiles and loads into Asterisk properly so presumptions would be that it works as well.

Files included in tarball:
app_nv_backgrounddetect.c
app_nv_backgrounddetect.c.1.4.2x.patch
app_nv_faxdetect.c
app_nv_faxdetect.c.1.4.2x.patch
app_nv_Makefile.patch
README

Enjoy!!!
//Drew Thomson