Qt-DAB

Qt-DAB is a Software for Windows, Linux and Raspberry Pi for Digital Audio Broadcasting (DAB and DAB+). It is the successor of both DAB-rpi and sdr-j-DAB, two programs created by the author that did DAB decoding.

Introduction
Features
Installation
Copyright

Features

DAB (mp2) and DAB+ (HE-AAC v1, HE-AAC v2 and LC-AAC) decoding
MOT SlideShow (SLS)
Dynamic Label (DLS)
Both DAB bands supported:
- VHF Band III
- L-Band (only used in Czech Republic and Vatican)
Spectrum view (incl. constellation diagram)
Scanning function (scan the subsequent channels in the selected band until a channel is encountered where a DAB signal is detected)
Detailed information for selected service (SNR, bitrate, frequency, ensemble name, ensemble ID, subchannel ID, protection level, CPU usage, language, 4 quality bars)
Dumping of the complete DAB channel (produces large raw files!) and playing them again later
Saving audio as uncompressed wave file
Supports various inputs from
- Airspy including Airspy mini,
- SDR DAB sticks (RTL2838U or similar),
- SDRplay and
- prerecorded dump (*.raw, *.iq and *.sdr)

Not (yet) implemented:

DMB (Audio and Video)
TPEG
EPG: when configured, the EPG decoding will generate so called EHB files.
Journaline (an untested journaline implementation is part of the sources)
Other bands than used for terrestrical broadcasting in Europe (like DAB over cable)
HackRF

Introduction

Qt-DAB is the result of merging the DAB-rpi and the sdr-j-DAB programs of the author. It became more and more complex to maintain different versions: modifications made in one version, did not always end up in the other versions so the versions started to diverge.

Since furthermore a separate "command line only" version is developed (a version not using Qt at all), while a large part of the sources is also used in the development of a version handling ETI files, there was a real need to reorganize.

It was therefore decided to merge the DAB-rpi and sdr-j-DAB version and rename the result - to distinguish from the Qt-free version - Qt-DAB.

The Qt-free version, the "command line only" version, is named "dab-cmdline", is built around a library that does the DAB decoding, and has its own repository.

The software - both the Qt-DAB and the dab-cmdline version - supports decoding of terrestrial DAB and DAB+ reception with as input the samplestream from either an AIRSPY, a SDRplay or a dabstick (rtl_sdr)s

The Qt-DAB version also supports input from an rtl-tcp server and prerecorded files (*.sdr and *.raw), which obviously provides the opportunity of dumping the input into a file.

Since the Qt-DAB version has to run on a headless RPI 2, using the home WiFi, in- or excluding the part for showing the spectrum and the constellation, is determined by setting the configuration.

Furthermore, as the Qt-DAB version has to run on a headless RPI 2, a configuration option is included to have the sound output delivered its samples through a TCP connection.

For further information please visit http://www.sdr-j.tk

An (outdated) manual in PDF format can be found at http://www.sdr-j.tk/sdr-j-dab-manual-0.99.pdf (is valid for qt-dab as well)

Some settings are preserved between program invocations, they are store in a file .qt-dab.ini, maintained in the home directory. The background colors of the spectrum can be changed by setting them in this .qt-dab.ini file, e.g.

displaycolor=blue
gridcolor=red

Windows

There are two executable (exe files) to be found under https://github.com/JvanKatwijk/qt-dab/releases . One is with a spectrum viewer and constellation diagram, the other without. Please copy them into the same directory you've unzipped http://www.sdr-j.tk/windows-bin.zip as it uses the same libraries.

If you want to compile it by yourself, please install Qt through their online installer, see https://www.qt.io/

Ubuntu Linux

For generating an executable under Ubuntu, you can put the following commands into a script.

Fetch the required components

sudo apt-get update
sudo apt-get install qt4-qmake build-essential g++
sudo apt-get install libsndfile1-dev qt4-default libfftw3-dev portaudio19-dev  
sudo apt-get install libfaad-dev zlib1g-dev rtl-sdr libusb-1.0-0-dev mesa-common-dev 
sudo apt-get install libgl1-mesa-dev libqt4-opengl-dev libsamplerate-dev libqwt-dev
cd

Fetch the required libraries

a) Assuming you want to use a dabstick as device, fetch a version of the library for the dabstick

wget http://sm5bsz.com/linuxdsp/hware/rtlsdr/rtl-sdr-linrad4.tbz
tar xvfj rtl-sdr-linrad4.tbz 
cd rtl-sdr-linrad4
sudo autoconf
sudo autoreconf -i
./configure --enable-driver-detach
make
sudo make install
sudo ldconfig
cd

b) Assuming you want to use an Airspy as device, fetch a version of the library for the Airspy

sudo apt-get install build-essential cmake libusb-1.0-0-dev pkg-config
wget https://github.com/airspy/host/archive/master.zip
unzip master.zip
cd host-master
mkdir build
cd build
cmake ../ -DINSTALL_UDEV_RULES=ON
make
sudo make install
sudo ldconfig

Clean CMake temporary files/dirs:

cd host-master/build
rm -rf *

Get a copy of the Qt-DAB sources

git clone https://github.com/JvanKatwijk/qt-dab.git
cd qt-dab

Edit the qt-dab.pro file for configuring the supported devices and other options. Comment the respective lines out if you don't own an Airspy (mini) or an SDRplay.
If DAB spectrum and the constellation diagram should be displayed, check the installation path to qwt. If you were downloading it from http://qwt.sourceforge.net/qwtinstall.html please mention the correct path in qt-dab.pro file (for other installation change it accordingly):

INCLUDEPATH += /usr/local/include  /usr/local/qwt-6.1.3

Build and make

qmake qt-dab.pro
make

You could also use QtCreator, load the qt-dab.pro file and build the executable.

Remark: The excutable file can be found in the sub-directory linux-bin. A make install command is not implemented.

Configuring using the qt-dab.pro file

Options in the configuration are:

a) select or unselect devices

b) select the output: soundcard or tcp connection

c) select or unselect basic MSC data handling

Adding or removing from the configuration is in all cases by commenting or uncommenting a line in the configuration file.

Comment the lines out by prefixing the line with a # in the qt-dab.pro file (section "unix") for the device(s) you want to exclude in the configuration. In the example below, sdrplay won't be used.

CONFIG          += dabstick
#CONFIG          += sdrplay
CONFIG          += rtl_tcp
CONFIG          += airspy

Input from prerecorded files is always part of the configuration.

Having the spectrum and the constellation shown, uncomment

CONFIG          += spectrum

For selecting the output to be sent to a RCP port, uncomment

CONFIG         += tcp-streamer         # use for remote listening

For showing some information on the selected program uncomment

DEFINES         += TECHNICAL_DATA

For basic MSC data handling, i.e. MOT handling etc, uncomment

DEFINES         += MSC_DATA__           # use at your own risk

The sourcetree contains a directory "sound-client", that contains sources to generate a simple "listener" for remote listening.

Configuring using CMake

The CMakeLists.txt file has all devices and the spectrum switched off as default. You can select a device (or more devices) without altering the CMakeLists.txt file, but by passing on definitions to the command line.

An example

cmake .. -DDABSTICK=ON -DRTLTCP=ON -DSPECTRUM=ON

will generate a makefile with both support for the dabstick and for the remote dabstick (using the rtl_tcp connection) and for the spectrum in the configuration.

Devices that can be selected this way are, next to the dabstick and rtl_tcp, the sdrplay and the airspy.

The default location for installation depends on your system, mostly /usr/local/bin or something like that. Set your own location by adding

-DCMAKE_INSTALL_PREFIX=your installation prefix

For other options, see the CMakeLists.txt file.

Note that CMake expects Qt5 to be installed.

SDRplay

The current set of sources has some support for the RSP-II. It is assumed that at least library version 2.09 is installed.

Raspberry PI

The Qt-DAB software runs pretty well on the author's RPI-2. The average load on the 4 cores is somewhat over 60 percent.

One remark: getting "sound" is not always easy. Be certain that you have installed the alsa-utils, and that you are - as non-root user - able to see devices with aplay -L

In arch, it was essential to add the username to the group "audio".

Note that on the current distribution of Raspbian Jessie (i.e. January 2017) the best way to generate the executable for Qt-DAB is to use Qt4. The qwt library - needed if you want the spectrum viewer and the constellation diagram - in the distribution is compiled with Qt4.

Qt

The software uses the Qt library and - for the spectrum and the constellation diagram - the qwt library.

The CMakeLists.txt assumes Qt5, if you want to use Qt4, and you want to have the spectrum in the configuration, be aware of the binding of the qwt library (i.e. Qt4 and a qwt that uses Qt5 does not work well). As mentioned above, in the (January 2017) distribution of Raspbian Jessie, the qwt library provided is compiled against Qt4.

Copyright

Copyright (C)  2013, 2014, 2015, 2016, 2017
Jan van Katwijk (J.vanKatwijk@gmail.com)
Lazy Chair Programming

The Qt-DAB software is made available under the GPL-2.0.
The SDR-J software, of which the Qt-DAB software is a part, 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.

sjndhkl / qt-dab