cap-dab-server is a piece of software that combines existing DAB broadcasting utilities (from ODR-mmbTools) with a friendly user-interface into a solution capable of translating CAP (Common Alerting Protocol) messages to a DAB/DAB+ emergency warning broadcast. cap-dab-server can also server as an easy-to-use frontend to setup a simple DAB/DAB+ ensemble without utilizing any of the CAP or announcement functionality. You might find its feature set somewhat limited compared to the manually editing the configuration files provided by ODR-mmbTools (see Limitations).

Features include:

• A TUI management interface to view status, logs and configure general settings
• Simple TUI configuration of the DAB multiplexer
• Option to send warning messages using the DAB Alarm announcement or "old school" stream replacement (see also "Warning method").
• Ability to switch channel's stream sources on the fly
• Spoken (Text To Speech) CAP description
• Option to send raw CAP messages as packet data over DAB (for integration with cfns-half-duplex, see image below)

Installation

Requirements:

• dialog (TUI)
• espeak-ng (on Linux only)
• ffmpeg (Convert mp3 TTS output to wav)
• gstreamer (GStreamer input, optional)
• odr-audioenc (DAB/DAB+ Encoder)
• odr-padenc (DAB PAD Encoder)
• odr-dabmux (DAB Multiplexer)
• odr-dabmod (DAB Modulator)
• Python 3.10+
• python-Flask (HTTP server)
• python-pyttsx3 (TTS)
• python-pythondialog (TUI)
• python-pyzmq (IPC with ODR-mmbTools)

Clone this repository and install above dependencies using the instructions for your platform below.

odr-mmbTools

You'll have to compile and install odr-mmbTools manually. By default, cap-dab-server assume the binaries to be installed to /usr/local/bin. This can be changed in the server settings after the first run.

odr-mmbTools need to be configured with at least the following features:

odr-audioenc:	--enable-gst (gst)
odr-padenc:	(magickwand)
odr-dabmux:	--enable-output-raw (file fifo udp tcp raw simul zmq)
odr-dabmod:	

Debian/Ubuntu

$ sudo apt install dialog espeak-ng gstreamer1.0-plugins-* libespeak-ng-libespeak1 ffmpeg python3 python3-dialog python3-flask python3-pip
$ pip3 install --user pyttsx3 pyzmq

macOS

$ brew install dialog ffmpeg gstreamer python
$ pip3 install --user flask pyttsx3 pythondialog pyzmq

Windows

TODO

Configuration

Configuration is largely done using the Admin TUI (Terminal User Interface).

NOTE: Currently the Admin Interface is closely integrated with the CAP-DAB server. This means the cap-dab-server is not able to run in the background. Running the server is the background is still possible using terminal multiplexer such as GNU Screen and detaching from the session.

A DAB in cap-dab-server ensemble consists of services and streams. A DAB ensemble is broken down into one or more services. Services provide one stream, which can be i.e. a HTTP audio stream, a named pipe with arbitrary data or single (looped) audio file.
A stream consists of one or more service components, which refer to for instance an audio stream and a data stream. cap-dab-server limits

TODO image of the relation between streams, services, subchannels and components

Ensemble

First, let us configure our ensemble.

1. Start cap-dab-server by running:

$ ./main.py

2. You'll be presented with several options, let's navigate to DAB > Ensemble first. Here, change your Country and Ensemble Label from the defaults where needed.

In section 'Alarm announcements', we'll configure which announcement will switch to which stream later.

NOTE: When navigating back to DAB Configuration, make sure to press Save to save your configured changes and restart the DAB server.

Services and Streams

When cap-dab-server is first started, a simple ensemble is automatically configured, but services and stream have to be added manually before you can begin broadcasting.

Let's add a stream first.

1. From the main menu, go to DAB > Streams > Add.
2. Enter a simple identifier for the stream such as sub-audio.
3. Now, set the stream source by selecting Stream Input. Let's make this a DAB+ stream. Navigate to DAB+ with the arrow keys and press Spacebar to select.
   Return will move to the next screen.
4. Select the input source type, choose GStreamer to use an HTTP web-stream for example.
5. In the next screen, enter the path (for File and FIFO) or the GSTURI (for GStreamer). In our example, we'll use a local VLC instance streaming a playlist on 127.0.0.1:1234. Enter http://127.0.0.1:1234 and press Return.
6. We are all done for now.
   The remaining options can be modified later, but the defaults are relatively sane.

Let's add a new service now.

1. Navigate back to DAB Configuration and go to Services > Add.
2. Enter an identifier such as srv-audio and press Return.
3. For the service ID, use any value, such as dab and press Return.
4. In the next screen, select the stream we've just created.
5. All done for now.
   From here, you can optionally configure any other service parameters if you desire.

NOTE: When navigating back to DAB Configuration, make sure to press Save to save your configured changes and restart the DAB server.

Broadcasting

cap-dab-server automatically starts ODR-DabMod. Configuration for ODR-DabMod however, cannot be configured from the TUI Admin interface. By default, cap-dab-server expects the configuration file to be located in $XDG_CONFIG_HOME/cap-dab-server/dabmod.ini.

A sample dabmod.ini for use with a HackRF-One can be found in doc/dabmod_hackrf.ini.

Alarm announcements

You can configure what announcements are supported by what service:

1. Navigate to DAB > Services > [service] > Announcements
2. Select which announcements you want this service to support

Announcements will instruct DAB receivers to switch to another channel (if supported by the received). This is configured ensemble-wide.
Currently, the ensemble announcement settings are not configurable from the TUI. Instead, you'll have to edit the ODR-DabMux configuration file manually. This can be done by opening $XDG_CONFIG_HOME/cap-dab-server/dabmux.mux with your preferred text-editor. Please refer to the sample configuration file included with ODR-DabMux for instructions. We hope to add this functionality in future releases.

CAP announcements

Settings for CAP announcements are fully customizable from the TUI. The settings can be found in DAB > Warning settings and CAP.

Limitations

• OE (Other Ensemble) announcement switching is not supported
• Secondary service components are currently not configurable from the TUI
• Not all other features of ODR-DabMux are currently supported
• Editing the ODR-DabMod configuration file from the UI is currently not supported

TODO

• Change Alarm channel/stream replacement DLS text (and change back after cancel)
• TUI config - Ensemble announcement
• TUI config - DAB modulator
• TUI config - Packet address
• Option to send CAP messages from the TUI
• Logging - Add stream logs to GUI
• Option to use ODR-DabMod config file instead of fifo output
• Option to restart threads that have quit
• Implement more of the CAP spec (message updates, ...)
• Split admin interface from server component
• Don't start the CAP server and Watcher thread if all warning methods are disabled

Known issues

• English (en-US) TTS output doesn't generate correctly on macOS, consider using another TTS library than pyttsx3

License

This project is licensed under the GNU General Public License v3.0. See LICENSE for more information.

Credits

Credits to OpenDigitalRadio for the excellent open-source ODR-mmbTools DAB/DAB+ software tools.

Credits to Felix Morgner and Tobias Stauber for their work on the data-over-dab-example code. I have derived from their work and (mostly) rewritten it in Python to integrate into this project.

Credit to Adeola Bannis of the University of California for BoostInfoParser.