SIP-based Announcement / PA / Paging / Public Address Server system
Project description
WARNING: project is in early stages of development and not suitable for any kind of general usage yet
SIP-based Announcement / PA / Paging / Public Address Server system.
Main component of this project is a script to run PJSUA SIP client connected to a JACK sound server routing audio to whatever sound cards and speaker sets.
It picks up calls, plays klaxon on speakers, followed by the announcement made in that call. Music plays in-between announcements.
Script controls PJSUA and JACK to make them work to that effect.
Usage
After installation (see below), the script should be configured, providing it with at least the SIP account data for the general usage.
Configuration file (ini format) locations:
paging.conf
/etc/paging.conf
callpipe.conf
/etc/callpipe.conf
Paths specified on the command line.
All files will be looked up and parsed in that order, values in next ones overriding corresponding ones in the previous and defaults.
See output of paging --help for info on how to specify additional configuration, more up-to-date list of default paths, as well as general information for all the other options available.
Provided paging.example.conf file has all the available configuration options and their descriptions.
To see default configuration options, use paging --dump-conf-defaults, and run paging --dump-conf ... to see the actual options being picked-up and used at any time.
There are two general (supported) ways to start and run the script:
In the foreground (non-forking).
As a systemd service.
Both are described in more detail below.
Start/run in the foreground
Aka simple non-forking start.
Just run the thing as:
paging
Can be used directly from terminal, or with any init system or daemon manager, including systemd, upstart, openrc, runit, daemontools, debian’s “start-stop-daemon”, simple bash scripts, etc.
For systemd in particular, see the “Running as a systemd service” section below.
Running from terminal to understand what’s going on, these options might be also useful:
paging --debug paging --debug --pjsua-log-level 10 paging --dump-conf
See also “Installation” and “Audio configuration” sections below.
Running as a systemd service
TODO
Installation
This is a regular package for Python 2.7 (not 3.X), but with some extra run-time requirements (see below), which can’t be installed from PyPI.
Package itself can be installed at any time using pip, e.g. via pip install PagingServer (this will try to install stuff to /usr!!!).
Unless you know python packaging though, please look at pip2014.com, python packaging tutorial or documentation below for more detailed step-by-step instructions for both python package and other requirements.
Requirements
Python 2.7 (NOT 3.X).
PJSUA (PJSIP User Agent) and its python bindings.
Can be packaged as “pjsip”, “pjsua” or “pjproject” in linux distros.
Python bindings (from the same tarball) can also be packaged separately as “python-pjproject” or something like that.
If either of those isn’t available, be sure to build and install pjsua AND its python bindings manually from the same sources, and NOT e.g. install pjsua from package and then build bindings separately.
JACK - both JACK1 (C) and JACK2 (C++) forks should work.
Only tested with JACK1 fork, but as both have same ABI and only interacted with via libjack, there should be no difference wrt which one is actually running.
(optional) ffmpeg binary - if audio samples are not wav files (will be converted on every startup, if needed).
(optional) python-systemd - only if --systemd option is used (e.g. with shipped .service file).
Developed and shipped separately from main systemd package since v223 (2015-07-29), likely comes installed with systemd prior to that.
Would probably make sense to install that module from OS package, which should be available if systemd is used there as init by default.
(optional) raven python module - for reporting any errors via sentry.
Step-by-step installation process
It’s recommended to follow these in roughly same order, as next ones might rely on stuff installed in the previous ones.
Each step can be skipped entirely if “Verify or check” commands for it work, when packages in question were installed through some other means. But be sure to run at least those commands to spot any potential issues.
Line prefixed by “%” are meant to be executed in the terminal with that prefix removed.
Install generic build tools and python dev packages.
Debian / Ubuntu:
% apt-get install python python-pip python-virtualenv
Arch Linux:
% pacman -S python2 python2-pip python2-virtualenv
Verify or check if already installed:
% pip --version pip 1.5.6 from /usr/lib/python2.7/dist-packages (python 2.7) % virtualenv --version 1.11.6
Note that on some systems, “pip” for python-2.7 might be installed as “pip2” or “pip-2.7”, same might apply to “virtualenv”, substitute these as necessary.
Build/install PJSIP project and its python bindings.
If PJSIP (can also be called: pj, pjsip, pjproject, pjsua) packaged for your distro (e.g. pjproject packages for Debian Sid, or in AUR on Arch), it might be easier to install these and avoid building them from scratch entirely.
See also all the great PJSIP build/installation instructions:
Below in this step is just a shorter version of these.
Some operations below, such as obvious package manager invocations, and where otherwise noted, should be run as “root”, or can be prefixed with “sudo”, if necessary.
Install build-tools and python headers:
Debian: apt-get install build-essential python-dev
Arch: pacman -S base-devel
On source-based distros like Gentoo, gcc, headers and such are always come pre-installed, so neither “build tools” nor “dev”-type extra packages are necessary.
Verify or check if tools/headers are already installed:
% cc --version cc (Debian 4.9.2-10) 4.9.2 % make --version GNU Make 4.0 % python2-config --includes -I/usr/include/python2.7 -I/usr/include/x86_64-linux-gnu/python2.7
Get the latest release of PJSIP code from http://www.pjsip.org/download.htm with one of these commands (substituting newer release URL, if possible):
% wget http://www.pjsip.org/release/2.4.5/pjproject-2.4.5.tar.bz2 && tar xf pjproject-2.4.5.tar.bz2 ### or % curl http://www.pjsip.org/release/2.4.5/pjproject-2.4.5.tar.bz2 | tar xj ### or (NOT RECOMMENDED, can be too buggy) % svn export http://svn.pjsip.org/repos/pjproject/trunk pjproject
Build the code:
% cd pjproject* % ./configure --prefix=/usr --enable-shared --disable-v4l2 --disable-video % make dep % make
TODO:
NO NO NO, this is WRONG, because pj* stuff will build against internal portaudio without JACK, so needs –with-external-pa flag and there should be a note on installing PA itself above
Install pjsip/pjsua libs (should be done root or via sudo):
On Debian/Ubuntu (or similar distros):
% apt-get install checkinstall % sed -i 's/^\(\s\+\)cp -af /\1cp -r /' Makefile % checkinstall -y ... ********************************************************************** Done. The new package has been installed and saved to /root/pjproject-2.4.5/pjproject_2.4.5-1_amd64.deb You can remove it from your system anytime using: dpkg -r pjproject ********************************************************************** % dpkg -s pjproject ... Status: install ok installed ...
This will create (via “checkinstall” tool) and cleanly install .deb package to the system, making it easy to remove/update it later.
If “checkinstall” isn’t your cup of tea, more generic way below should work as well.
On any random linux/unix distro:
% make install
Easy, but there’s almost always a better way, that makes packaging system aware of (and hence capable of managing) the installed files.
Install python pjsua bindings (should be done root or via sudo):
On Debian/Ubuntu (or similar distros):
% pushd pjsip-apps/src/python % checkinstall -y --pkgname=python-pjsua python2 setup.py install % popd
Same as above, using “checkinstall” is highly recommended on these distros.
On any generic linux (or similar system):
% pushd pjsip-apps/src/python % python2 setup.py install % popd
... install --user can be used to install package for current user only, or whole step can be performed with virtualenv active to install it there.
Note that pjsua bindings are just a regular python package, and hence subject to any general python package installation/management guidelines, e.g. aforementioned python packaging tutorial.
Verify or check if pjsip/pjproject/pjsua are all installed and can be used from python:
% python2 -c 'import pjsua; lib = pjsua.Lib(); lib.init(); lib.destroy()' 04:43:41.097 os_core_unix.c !pjlib 2.4.5 for POSIX initialized 04:43:41.097 sip_endpoint.c .Creating endpoint instance... 04:43:41.097 pjlib .select() I/O Queue created (0x230f630) 04:43:41.097 sip_endpoint.c .Module "mod-msg-print" registered 04:43:41.097 sip_transport. .Transport manager created. 04:43:41.098 pjsua_core.c .PJSUA state changed: NULL --> CREATED
Last command should not give anything like “ImportError” or segmentation faults, and should exit cleanly with output similar to one presented above.
Install JACK sound server.
JACK is very mature and widely-used project, hence is packaged for all major linux distros, hence it’s better to install it using distro’s package manager.
There are two different forks of JACK, both are in use and maintained - JACK1 (C) and JACK2 (C++).
It is recommended to install JACK1 (or simply “jack”, not e.g. “jack2”) package, as this script is tested to work with that fork, but “jack2” should likely work just as well.
Debian/Ubuntu:
apt-get install --no-install-recommends jackd1
Note --no-install-recommends flag, which should prevent Debian from installing “recommended” GUI packages and X11 server for these. None of them are needed or helpful, hence that option here.
“Realtime process priority” option (which apt-get might ask) is irrelevant.
Arch Linux: pacman -S jack
Other distros: build it (JACK1) from http://jackaudio.org/downloads/
Verify or check if already installed:
% jackd --version jackd version 0.124.1 tmpdir /dev/shm protocol 25
Here versions 0.X (such as in example above) will indicate that JACK1 is installed and versions 1.X for JACK2.
Prepare environment for PagingServer, install it and its python dependency modules.
It’d be unwise to run this app as a “root” user, so special uid should be created for it (from a root user), along with home directory, where all app files will reside:
% useradd -d /srv/paging paging % mkdir -p -m700 ~paging % chown -R paging: ~paging
“User=paging” is also used in systemd unit (installed and explained below), so if other user name will be used here, it should be changed there as well.
Same goes for directory used here.
Then, for all the next commands in this step, shell should be switched to the created user, which can be done by running “su” with root privileges:
% su - paging % id uid=1001(paging) gid=1001(paging) groups=1001(paging)
This should likely also change the shell prompt, and “id” command should give non-root uid/gid (as shown above).
IMPORTANT: DO NOT skip any errors from command above before running the next steps.
Create python virtualenv for installing the app there:
% virtualenv --clear --system-site-packages --python=python2.7 PagingServer % exec bash % cd PagingServer % . bin/activate % python2 -c 'import sys; print sys.path[1]' /srv/paging/PagingServer/lib/python2.7
Last command can be used to verify that sys.path[1] indeed points to a subdir in ~paging, and not something in /usr, which means that virtualenv was correctly activated for this shell session.
Install the app and all its python module dependencies:
% pip install PagingServer Downloading/unpacking PagingServer ... Downloading/unpacking JACK-Client (from PagingServer) ... Successfully installed PagingServer Cleaning up...
Make sure app is installed and works with installed pjsua version:
% paging --version paging version-unknown (see python package version) % paging --dump-pjsua-conf-ports Detected conference ports: ... % paging --dump-pjsua-devices Detected sound devices: ... % paging --dump-conf ;; Current configuration options ...
As usual, there should be no error messages for these commands.
To return back to root shell after running su - paging command above (should be still active), exit command can be used or a “Ctrl + d” key combo.
To later get back to same “paging” user shell and installed python virtualenv, use the following commands (same as used above during virtualenv setup):
% su - paging % . PagingServer/bin/activate
Any (at least non system-wide) python stuff for the app should be tweaked or installed only after running these (and until exiting the shell).
(optional) Start JACK sound server.
It is important to do this before running PagingServer, as the latter depends on jackd in general, though can start it by itself with “jack-autostart = yes” configuration option.
Unless that option will be used (not recommended, as there might be other apps still needing JACK to be started explicitly - e.g. music players), JACK daemon (jackd) should be always started before PagingServer, using the same uid (“paging”) as the app.
Start jackd in one of the following ways (assuming initial root shell):
% sudo -u paging -- setsid jackd --nozombies -d dummy & % disown ### or % su - paging % setsid jackd --nozombies -d dummy & % disown ### or (if systemd is used in OS as init) % systemd-run --uid=paging -- jackd --nozombies -d dummy
Here -d dummy output is used to avoid relying on any particular sound hardware available.
Any ALSA (linux audio hardware stack) devices can be connected to this jackd server later via “alsa_in” / “alsa_out” commands, installed along with JACK1 server.
See JACK documentation (for particular fork that is used, as this process is different between JACK1 / JACK2) for more details on how to connect this sound server to the actual audio hardware.
Started without any extra options (on top of what’s shown above), this jackd will have “default” server name, and should be used by default by all jack-enabled apps (e.g. music players and such), including PagingServer itself.
Configure PagingServer and install binary/configuration files for running it as a system service.
Install symlink to a “paging” script into system-wide $PATH (as root):
% ln -s ~paging/PagingServer/bin/paging /usr/local/bin/ % paging --version paging version-unknown (see python package version)
Despite binary being available to all users after that, DO NOT run the actual service as a “root” user, at least outside of very exceptional cases (e.g. maybe checking if it works as root due to dev/file access permissions).
Get annotated paging.example.conf from the github repository or pypi package (included there, but not actually installed):
% wget https://raw.githubusercontent.com/AccelerateNetworks/PagingServer/master/paging.example.conf ### or % curl -O https://raw.githubusercontent.com/AccelerateNetworks/PagingServer/master/paging.example.conf
Edit file as necessary (see comments there and configuration-related info in this README), and put it to /etc/paging.conf (requires root privileges):
% nano paging.example.conf % install -o root -g paging -m640 -T paging.example.conf /etc/paging.conf
/etc/paging.conf is one of the default locations where app looks for configuration file (see paging --help output for a full list of such locations).
Test-run the service as a proper “paging” user (created in previous step) in one of the following ways (assuming starting shell is root):
% sudo -u paging -- paging --debug ### or % su - paging % paging --debug ### or (if systemd is used in OS as init) % systemd-run --uid=paging -- paging --debug % journalctl -n30 -af # to see output of the ad-hoc service there
If correctly configured and working, there should be plenty of “DEBUG” output (due to --debug option in commands above), but no errors, especially fatal ones that cause the app to crash.
Configure system to run PagingServer and jackd on boot and start these as system services.
TODO: systemd stuff here, some notes on same process for SysV init.
If anything in the steps above is unclear, misleading or does not work, and can be fixed, please leave a comment on- or file a new github issue, describing what’s wrong and how it can be done better or corrected.
More info on how to file these in a most efficient, useful and productive way can be found e.g. in this “Filing Effective Bug Reports” article.
Audio configuration
Overview of the software stack related to audio flow:
PJSUA picks-up the calls, decoding audio streams from SIP connections.
PJSUA outputs call audio to via PortAudio.
PortAudio can use multiple backends on linux systems, including:
ALSA libs (and straight down to linux kernel)
OSS (/dev/dsp*, only supported through emulation layer in modern kernels)
JACK sound server
PulseAudio sound server (with a somewhat unstable patch, see comment on #3 for details)
In this particular implementation, JACK backend is used, as it is necessary to later multiplex PJSUA output to multiple destinations and mix-in sounds from other sources there.
So PortAudio sends sound stream to JACK.
JACK serves as a “hub”, receiving streams from music players (mpd instances), klaxon sounds, calls picked-up by PJSUA.
JACK mixes these streams together, muting and connecting/disconnecting some as necessary, controlled by the server script (“paging”).
End result is N stream(s) corresponding to (N) configured hardware output(s).
JACK outputs resulting sound stream(s) through ALSA libs (and linux from there) to the sound hardware.
Hence audio configuration can be roughly divided into these sections (at the moment):
Sound output settings for PJSUA.
Related configuration options:
pjsua-device
pjsua-conf-port
As PortAudio (used by pjsua) can use one (and only one) of multiple backends at a time, and each of these backend can have multiple “ports” in turn, pjsua-device should be configured to use JACK backend “device”.
To see all devices that PJSUA and PortAudio detects, run:
% paging --dump-pjsua-devices Detected sound devices: [0] HDA ATI SB: ID 440 Analog (hw:0,0) [1] HDA ATI SB: ID 440 Digital (hw:0,3) [2] HDA ATI HDMI: 0 (hw:1,3) [3] sysdefault [4] front [5] surround21 [6] surround40 ... [13] dmix [14] default [15] system [16] PulseAudio JACK Source
(output is truncated, as it also includes misc info for each of these devices/ports that PortAudio/PJSUA provides)
This should print a potentially-long list of “playback devices” (PJSUA terminology) that can be used for output there, as shown above.
JACK default output (as created by e.g. -d dummy option to jackd) in the example list above is called “system” - same as in JACK, and should be matched by default.
If any other JACK-input/PortAudio-output should be used, it can be specified either as numeric id (number in square brackets on the left) or regexp (python style) to match against name in the list.
To avoid having any confusing non-JACK ports there, PortAudio can be compiled with only JACK as a backend.
pjsua-conf-port option can be used to match one of the “conference ports” from paging --dump-pjsua-conf-ports command output in the same fashion, if there will ever be more than one (due to more complex pjsua configuration, for example), otherwise it’ll work fine with empty default.
JACK daemon startup and control client connection configuration.
Related configuration options:
jack-autostart
jack-server-name
jack-client-name
All of these are common JACK client settings, described in jackd(1), jackstart(1) manpages, libjack or jack-client module documentation.
With exception for self-explanatory jack-autostart (enabled by default), these options should be irrelevant, unless this script is used with multiple JACK instances or clients.
Configuration for any non-call inputs (music, klaxons, etc) for JACK.
Related configuration options:
klaxon
jack-music-client-name
jack-music-links
“klaxon” can be a path to any file that has sound in it (that ffmpeg would understand), and will be played before each announcement call on all “jack-output-ports” (see below), and before that call gets answered.
“jack-music-client-name” should be a regexp to match outputs of music clients, that should play stuff in-between announcements, and “jack-music-links” allows to control which set(s) of speakers they’ll be connected to.
For example, if mpd.conf has something like this:
audio_output { type "jack" name "jack" client_name "mpd.paging:test" }Then configuration like this (these are actually defaults):
jack-music-client-name = ^mpd\.paging:(.*)$ jack-music-links = left---left right---right
Will connect output from that player to all speakers matched by “jack-output-ports” (all available to JACK by default).
Script can be run with --dump-jack-ports option to show all JACK ports that are currently available - all connected players, speakers, cards and such.
See more detailed description of these options and how they’re interpreted in paging.example.conf.
List of hardware outputs (ALSA PCMs) to use as JACK final outputs/sinks.
Related configuration options:
jack-output-ports
Same as with PJSUA outputs/ports above, jack-output-ports can be enumerated via paging --dump-jack-ports command, and filtered by direct id or name regexp, if necessary.
Default is to route PJSUA call to all outputs available in JACK.
All settings mentioned here are located in the [audio] section of the configuration file.
See paging.example.conf for more detailed descriptons.
Misc tips and tricks
Collection of various things related to this project.
Pre-convert klaxon sound(s) to wav from any format
Can be done via ffmpeg with:
ffmpeg -y -v 0 -i sample.mp3 -f wav sample.wav
Where it doesn’t actually matter which format source “sample.mp3” is in - can be mp3, ogg, aac, mpc, mp4 or whatever else ffmpeg supports.
Might help to avoid startup delays to conversion of these on each run.
If pjsua will be complaining about sample-rate difference between wav file and output, -ar 44100 option can be used (after -f wav) to have any sampling rate for the output file.
Running JACK on a system where PulseAudio is the main sound server
First of all, jackd has to be started manually there, and strictly before pulseaudio server.
Then, /etc/pulse/default.pa should have something like this at the end (after default sink init!):
load-module module-jack-source source_name=jack_in load-module module-loopback source=jack_in
That will create an output from JACK to PulseAudio and from there to whatever actually makes sound on the particular system, provided that the loopback stream and source in question are not muted and have some non-zero volume set in pulse.
“module-jack-source” has options for picking which jackd to connect to, if isn’t not “default”, “module-loopback” after it creates a stream from that jack source to a default sink (which is probably an ALSA sink).
On the JACK side, “PulseAudio JACK Source” port (sink) gets created, and anything connected there will make its way to pulseaudio.
Old README.md things
To be spliced here later, if still applicable:
## Benchmarking We've tested this script with thousands of calls, it is fairly reliable and light on resources. Total CPU use on a Pentium 4 @ 2.8ghz hovered around 0.5% with 4MB ram usage. identical figures were observed on a Celeron D @ 2.53Ghz, you could probably get away with whatever your operating system requires to run in terms of hardware. To benchmark, you'll need to set up callram.py. ### Setting up callram.py This setup assumes you have PJSUA installed, if not, go back to Installation earlier in this readme and install it. ### Put the files in the right places ``` sudo cp callram.py /opt/bin/callram.py sudo cp callram.example.conf /etc/callram.conf ``` ### Add your SIP account ``` sudo nano /etc/callram.conf ``` Change the top 3 values to your SIP server, username (usually ext. number) and password. Then fill in both SIP URI: fields (uri= and to=) with the SIP URI of the client you'd like to test. SIP URIs are usually formatted as `sip:<extension#>@<exampledomain.com>` in most cases. The Domain may sometimes be an IPv4 or IPv6 address depending on your setup. ## Running the Paging Server Run either of the commands below: ``` Run in bash/terminal: /usr/bin/python /opt/bin/callram.py ```
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