Open Source Audio Monitoring Software designed for (but not limited to) a Raspberry Pi with touchscreen. The application provides:

• A number of useful audio monitoring tools, including:
  • Digital meters of various flavours (BBC PPM, EBU, Nordic, VU etc)
  • "Moving Coil" meters of various flavours
  • Lissajou
  • Spectrum Analyser
  • R128 Loudness
  • Scope
• A number of audio test tools, including:
  • Channel delay measurement
  • Distortion measurements
  • Level monitoring
  • Peak Sample Count
  • Recording of incoming audio
  • LTC detection
• An audio generator that can output audio from a number of sources, including:
  • The input source
  • A file
  • A simple tone
  • A tone sequence
  • LTC

PAM can take in audio from a soundcard or Pi HAT or from an AES67 stream. There is both DNS-SD and SAP discovery of AES67 streams and also an NMOS version which complies to IS04/IS05.

For more information please look at the help files contained in the documents directory

• wxWidgets https://www.wxwidgets.org/
• PortAudio https://www.portaudio.com/download.html
• libsndfile https://www.mega-nerd.com/libsndfile/
• Secret Rabit Code https://www.mega-nerd.com/SRC/
• Avahi-Client
• OpenSSL
• libCurl

On Buster and earlier

sudo apt-get update
sudo apt-get install libwxgtk3.0-dev portaudio19-dev libsndfile1-dev libsamplerate0-dev libavahi-client-dev libcap-dev libssl-dev libcurl4-openssl-dev

On Bullseye

sudo apt-get update
sudo apt-get install libwxgtk3.0-gtk3-dev portaudio19-dev libsndfile1-dev libsamplerate0-dev libavahi-client-dev libcap-dev libssl-dev libcurl4-openssl-dev

PAM uses a number of small libraries. All these libraries are hosted on GitHub and are cloned automatically when running cmake.

• log a simple streaming log class
• dnssd a cross platform wrapper around Bonjour and Avahi for service browsing and publishing
• sapserver a library to detect and publish SAP
• ptpmonkey allows PAM to decode and analyse PTP messages and also sync to a PTP grandmaster
• asio used by sapserver and ptpmonkey
• Mongoose http and websocket library (only needed for the NMOS build)
• restgoose a Restful server built on top of Mongoose (only needed for the NMOS build)
• nmos an optional library to allow PAM to advertise itself as an NMOS node and also act as an NMOS client

Workspace and project files are supplied for Code::Blocks IDE. There are Debug and Release builds for Windows and Linux There are also CMakeLists.txt files. They have been tested on Linux using GCC

The easiest way to obtain the required GitHub libraries and build and install a PAM on Linux is by using CMake. The CMake build will clone all the required GitHub libraries if it can't find them and update them to their latest version if it can. By default it looks in your home directory. You can change this by passing in the variable DIR_BASE to cmake

cmake -DDIR_BASE=/home/user/pam_external

It is also possible to change the expected directory for each individual library

cmake -DDIR_LOG=logdir

The following directories can be defined

• DIR_NMOS the location of your nmos directory (or where you want it cloned to).
• DIR_PTPMONKEY the location of your ptpmonkey directory (or where you want it cloned to).
• DIR_SAPSERVER the location of your sapserver directory (or where you want it cloned to).
• DIR_DNSSD the location of your dnssd directory directory (or where you want it cloned to).
• DIR_LOG the location of your log directory (or where you want it cloned to).
• DIR_MONGOOSE the location of your Mongoose directory (or where you want it cloned to).
• DIR_ASIO the location of your asio directory (or where you want it cloned to).

To build and install all applications and libraries

cd {pam directory}/build
cmake ..
cmake --build .
sudo cmake --build . --target install

This will

• clone all releveant source code if necessary
• configure and build all applications and libraries
• install the executable pam2 in /usr/local/bin
• install all necessary libraries in /usr/local/lib/pam2
• set the relevant capabilities on the application
• create the required pam2.conf file in /etc.ld.so.conf.d and run ldconfig so Linux knows about the new libraries
• copy the required files from the documents directory

• Open external/live/live.workspace in Codeblocks
• Fill in the necessary global variables
• Build the workspace

• Open pam2.workspace in Codeblocks

• Fill in the necssary global variables

• Build the workspace

• Create a file called pam2.conf in directory /etc/ld.so.conf.d

• Add the following line to the file

/usr/local/lib/pam2

• Run the following command to update the library path

sudo ldconfig

In order for PAM to have the correct capabilities you need to run the following

setcap cap_sys_time,cap_sys_admin,cap_net_bind_service+ep absolutepathtopam/pam2

This is included by default.

When subscribing to an AoIP stream whose SDP defines a PTP reference PTPMonkey will listen for a Master Clock on the relevant domain and use the Master Clock's time for timestamping incoming RTP packets. The PTP plugin will also depend on this library being part of the base build

NMOS support can be build in to PAM allowing control of AoIP streams in to and out of the software from external devices. It is also possible to select and route NMOS compliant sources to the software for monitoring.

If you wish to include nmos in the application then run cmake .. -DNMOS=ON instead of cmake ...

Note: NMOS support is a work in progress. The Node library passes all the NMOS tests and the Client library can be used to make simple connections. Amongst other things

• Work is needed on the client side for systems with many nodes in order to display and filter them properly.

PAM expects a few files to live in a specific directory:

• If it doesn't exist create a directory called pam in your home directory.
• Copy the contents of the document directory to the pam directory.
• If you used CMake to build and install PAM then this will happen automatically

Links to these can be found here with the associated Releaes

Can be found in the wiki section