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README.md

DABlin – capital DAB experience

DABlin plays a DAB/DAB+ audio service – either from a received live transmission or from a stored ensemble recording (frame-aligned ETI-NI). Both DAB (MP2) and DAB+ (AAC-LC, HE-AAC, HE-AAC v2) services are supported.

The GTK GUI version in addition supports the data applications Dynamic Label and MOT Slideshow (if used by the selected service).

Screenshots

GTK GUI version

Screenshot of the GTK GUI version

Console version

Screenshot of the console version

Requirements

General

A recent GCC (with C++11 support) and CMake are required.

The following libraries are required:

  • mpg123 (1.14.0 or higher)
  • FAAD2
  • SDL2

The GTK GUI version in addition requires:

  • gtkmm

On Debian or Ubuntu, mpg123, FAAD2, SDL2 and gtkmm are packaged and all the required files can be installed using aptitude or apt-get, for example:

sudo apt-get install libmpg123-dev libfaad-dev libsdl2-dev libgtkmm-3.0-dev

On Fedora, mpg123, SDL2, and gtkmm are all packaged and can be installed thus:

sudo dnf install mpg123-devel SDL2-devel gtkmm30-devel

FAAD2 is not packaged in the main Fedora repository, but it is available in RPM Fusion repository. Once you have added RPM Fusion to the repositories, FAAD2 may be installed by:

sudo dnf install faad2-devel

If you do not wish to, or cannot, add the RPM Fusion repositories, you will have to download FAAD2, perhaps from here, and build and install manually.

Alternative DAB+ decoder

Instead of using FAAD2, DAB+ channels can be decoded with FDK-AAC. You can also use the modified version fdk-aac-dabplus of OpenDigitalradio itself, if already installed.

On Debian and Ubuntu, you can install FDK-AAC with:

sudo apt-get install libfdk-aac-dev

On Fedora, RPM Fusion is again needed and, if used, you can:

sudo dnf install fdk-aac-devel

When the alternative AAC decoder is used, the FAAD2 library mentioned above is no longer required.

After installing the library, to use FDK-AAC instead of FAAD2, you have to have -DUSE_FDK-AAC=1 as part of the cmake command.

Audio output

The SDL2 library is used for audio output, but you can instead choose to output the decoded audio in plain PCM for further processing (e.g. for forwarding to a streaming server).

In case you only want PCM output, you can disable SDL output and therefore omit the SDL2 library prerequisite. You then also have to have -DDISABLE_SDL=1 as part of the cmake command.

Surround sound

Services with surround sound are only decoded from their Mono/Stereo core, as unfortunately there is no FOSS AAC decoder which supports the required Spatial Audio Coding (SAC) extension of MPEG Surround at the moment.

Precompiled packages

Some users kindly provide precompiled DABlin packages on their own:

Compilation

If the gtkmm library is available both the console and GTK GUI executables will be built. If the gtkmm library is not available only the console executable will be built.

You can use, for example, the following command sequence in order to compile and install DABlin:

mkdir build
cd build
cmake ..
make
sudo make install

Usage

The console executable is called dablin, the GTK GUI executable dablin_gtk. Use -h to get an overview of all available options.

(Currently no desktop files are installed so it is not easy to start DABlin directly from GNOME Shell. For now, at least, start DABlin from a console.)

DABlin processes frame-aligned DAB ETI-NI recordings. If no filename is specified, stdin is used for input. You just have to specify the regarding Service ID (SID). The GUI version does not necessarily need this - in that case initially no service is played until one is chosen.

If you want to play a live station, you can use dab2eti from dabtools (ODR maintained fork) and transfer the ETI live stream via pipe, e.g.:

dab2eti 216928000 | dablin_gtk

You can also replay an existing ETI-NI recording, e.g.:

dablin -s 0xd911 mux.eti

It is possible to let DABlin invoke dab2eti. You therefore just have to specify the path to the dab2eti binary and the desired channel.

dablin -d ~/bin/dab2eti -c 11D -s 0xd911

In case of the GTK GUI version the desired channel may not be specified. To avoid the huge channel list containing all possible DAB channels, one can also state the desired channels (separated by comma) which shall be displayed within the channel list.

dablin_gtk -d ~/bin/dab2eti -c 11D -C 5C,7B,11A,11C,11D -s 0xd911

Using dab2eti the E4000 tuner is recommended as auto gain is supported with it. If you want/have to use a gain value you can specify it using -g.

In addition to the respective button, the GTK GUI version also allows the keyboard shortcut m to toggle muting the audio.

Status output

During (re-)synchronisation status messages are output. Also dropped Superframes or AU are mentioned.

If the Reed Solomon FEC was used to correct bytes of a Superframe, this is mentioned by messages of the format (3+) in cyan color. This shorter format is used as those messages occure several times with borderline reception. The digit refers to the number of corrected bytes within the Superframe while a plus (if present) indicates that at least one byte was incorrectable.

Audio Units (AUs) with invalid CRC are mentioned with short format messages like (AU #2) in red color, indicating that the CRC check on AU No. 2 failed and hence the AU was dismissed.

Standards

DABlin implements (at least partly) the following DAB standards:

General

  • ETSI EN 300 401 (DAB system)
  • ETSI TS 101 756 (Registered tables)
  • ETSI TS 103 466 (DAB audio)
  • ETSI TS 102 563 (DAB+ audio)
  • ETSI ETS 300 799 (ETI)

Data applications

  • ETSI EN 301 234 (MOT)
  • ETSI TS 101 499 (MOT Slideshow)

TODO

At the moment, DABlin is kind of a rudimentary tool for the playback of DAB/DAB+ services. It is planned to add support for further Program Aided Data (PAD) features.

Slideshow

The GTK GUI version supports the MOT Slideshow if used by the selected service. The slide window is initially hidden but appears as soon as the first slide has been received completely and without errors.

Currently the following limitations apply:

  • slideshows in a separate subchannel are not supported (just X-PAD);
  • for MOT the hardcoded (default) X-PAD Application Types 12/13 are used;
  • the TriggerTime field is not processed (except the value Now)

License

This software is licensed under the GNU General Public License Version 3 (please see the file COPYING for further details). GPLv3 Image

Please note that the included FEC lib by KA9Q has a separate license!

DABlin - capital DAB experience Copyright (C) 2015-2017 Stefan Pöschel

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.