Qt-DAB is a Software for Windows, Linux and Raspberry Pi for listening to terrestrial Digital Audio Broadcasting (DAB and DAB+). It is the successor of both DAB-rpi and sdr-j-DAB, two former programs by the same author.
- 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, used CUs, protection level, CPU usage, program type, language, 4 quality bars)
- Automatic display of TII (Transmitter Identification Information) data when transmitted
- Dumping of the complete DAB channel (Warning: produces large raw files!) into * sdr files and playing them again later
- Saving audio as uncompressed wave file
- Saving the ensemble content (audio and data streams, including almost all technical data) into a text file
- Supports various inputs from
- SDRplay (both RSP I and RSP II),
- Airspy, including Airspy mini,
- SDR DAB sticks (RTL2838U or similar), and
- prerecorded dump (*.raw, *.iq and *.sdr)
Not (Not yet or partly) implemented:
- DMB (Audio and Video)
- TPEG when configured, TPEG messages are being send to a TCP port, sources for a simple client are part of the source distribution.
- 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 terrestrial broadcasting in Europe (like DAB over cable) *proper handling of subservices
- HackRF
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 re-organize.
Therefore, it was decided to merge DAB-rpi and sdr-j-DAB and rename the result Qt-DAB - to distinguish from the Qt-free version.
The Qt-free version, the "command line only" version, is named dab-cmdline, and is built around a library that does the DAB decoding. It has its own repository on Github.
The Qt-DAB and the dab-cmdline version both support decoding of terrestrial DAB and DAB+ reception from either an AIRSPY, a SDRplay or a dabstick (rtl_sdr).
Next to these C++ based versions, a version in Java is being developed, it has its own repository on Github.
The Qt-DAB version also supports input from an rtl-tcp server and pre-recorded files (*.sdr, *.iq and *.raw), which obviously provides the opportunity of dumping the input into a (*.sdr)-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, the resulting PCM output can be sent - if so configured - to a TCP port (Sources for a small client are part of the source distribution).
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 stored in a file .qt-dab.ini, to be found in the home directory. See Comment on some settings for more details.
Windows releases can be found at https://github.com/JvanKatwijk/qt-dab/releases . 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 its online installer, see https://www.qt.io/
If you are not familar with compiling then please continue reading by jumping to chapter appImage which is much easier for Linux beginners.
Ubuntu 16.04 (and on) have good support for Qt5 and qwt (compiled for Qt5). For generating an executable under Ubuntu (16.04 or newer), you can put the following commands into a script. (For Ubuntu 14.04 look into the package manager for Qt4 packages)
-
Fetch the required components
sudo apt-get update sudo apt-get install qt5-qmake build-essential g++ sudo apt-get install libsndfile1-dev qt5-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 libqt5opengl5-dev libsamplerate0-dev libqwt-qt5-dev sudo apt-get install qtbase5-dev -
Fetch the required libraries
a) Assuming you want to use a dabstick (also known as rtlsdr) 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 airspyone_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.profile 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.profile (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 exacutable file can be found in the sub-directory linux-bin. A make install command is not implemented.
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, rtl_tcp (i.e. the connection to the rtlsdr server) won't be used.
CONFIG += dabstick
CONFIG += sdrplay
#CONFIG += rtl_tcp
CONFIG += airspy
In the Windows configuration one may also choose
CONFIG += extio
for use with (appropriate) extio handlers
Remark: Input from pre-recorded files (8 bit unsigned *.raw and *.iq' as well as 16-bit "wav" *.sdr` files) is configured by default.
In order to show the spectrum and the constellation shown, uncomment
CONFIG += spectrum
In such a case, when uncommenting
DEFINES += __QUALITY
a "quality indicator" (standard phase deviation of the demodulated signal) will be shown (smaller is better).
Audio samples are - by default - sent to an audio device using the portaudio library. Two alternatives are available:
For selecting the output to be sent to a TCP port, uncomment
#CONFIG += tcp-streamer # use for remote listening
The source tree contains a directory "sound-client", that contains sources to generate a simple "listener" for remote listening.
For selecting the output to be handled by the Qt system (default device only) uncomment
#CONFIG += qt-audio
For basic MSC data handling, i.e. MOT handling etc, uncomment
DEFINES += MSC_DATA__ # use at your own risk
An experimental configuration parameter is
CONFIG += try_epg
If try_epg is configured then EPG (which stands for Electronic Program Guide) data will be written to xml files. Please select the service carrying EPG data.
An experimental configuration parameter is
CONFIG += impulseresponse
if impulseresponse is configured, then another widget will appear
that will show the arrival of the signals from different transmitters
in the SFN. Note that the signal that is strongest is the signal further
processed.
THIS FEATURE IS NOT AVAILABLE WHEN CMake IS USED.
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 .. -DSDRPLAY=ON -DRTLTCP=ON -DSPECTRUM=ON
will generate a makefile with support for a) the SDRplay device, b) for the remote dabstick (using the rtl_tcp connection) and c) for the spectrum in the configuration.
Other devices that can be selected (beside dabstick and rtl_tcp) are sdrplay and airspy. Use -DRTLSDR=ON, or -DAIRSPY=ON after the cmake command if you want to configure them.
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.
Important: Note that CMakeLists.txt file expects the appropriate Qt version (and - if configured - the qwt library) to be installed.
The current set of sources provides support for both the RSP-I and the RSP-II, it is assumed that at least library version 2.09 is installed.
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).
The Qt-DAB software runs pretty well on the author's RPI-2. The average load on the 4 cores is somewhere between 50 and 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".
The most recent distribution of Raspbian Stretch (i.e. august 2017) supports both Qt5 and a qwt compiled against Qt5.
A (slightly experimental) AppImage is available (see the releases section) developed under and to be used for Raspbian Stretch. Note that the repositories for Raspbian Stretch contain libraries for the rtlsdr Dabsticks and the airspy, while the API library for the SDRplay can be downloaded from sdrplay.com. So, Qt-DAB can be used without the need for compiling anything.
The AppImage version does not contain the Spectrum - I am using it in a headless environment.
Since Raspbian Stretch is a Debian derivative, the description for creating a version under Ubuntu applies.
For the ".pro" file uncomment
#DEFINES += __THREADED_DECODING.
#DEFINES += __THREADED_BACKEND
for a maximal use of the 4 cores of the CPU.
If you want to create a version with a spectrum widget, uncomment the line "#CONFIG += spectrum"
For the CMakeLists.txt file, uncomment
#add_definitions (-D__THREADED_DECODING) #uncomment for the RPI
https://github.com/JvanKatwijk/qt-dab/releases contains a generated appImage which is created on Ubuntu 14.04 (Trusty), and uses Qt4 (so it basically should run on any x-64 based linux system that isn't too old.). It assumes that you have installed a device, either a dabstick (i.e. rtlsdr), an Airspy or a SDRplay. All further dependencies are included. There is only one file which you have to make executable in order to run.
Note that on start up the appImage will try to set the udev settings for the airspy and dabstick right. Libraries for the dabstick (i.e. rtlsdr) and airspy are part of the appImage. Note that while the SDRplay is selectable, the library for the device should be installed from the supplier, i.e. "www.sdrplay.com".
All further dependencies are included
For more information see http://appimage.org/
Some values of settings are maintained between program invocations. This is done in the (hidden) file .qt-dab.ini in the user's home directory.
Some settings are not influenced by buttons or sliders of the GUI, they will only change by editing the .ini file.
Typical examples are
saveSlides=1
when set to 0 the slides that are attached to audio programs will not be saved. If set to 1 the slides will be saved in a directory /tmp/qt-pictures (Linux) or in %tmp%\qt-pictures (Windows).
picturesPath
defines the directory where the slides (MOT slideshow) should be stored. Default is the home directory.
showSlides=1
when set to 0 the slides will not be shown.
has-presetName=1
when set the name of the selected service - that is selected when closing down the program - is kept and at the next invocation of the program, an attempt is made to start that particular service. The name of the service is kept as presetname=xxxx
The background colors of the spectrum can be changed by setting
displaycolor=blue
gridcolor=red
The Qt-DAB program now searches - if available - for TII (transmitter identification information) data in the FIC. If TII data is available, the small label at the bottom of the Technical Details widget will color green, and the main ID if the transmitters is shown. Also the list of geographical positions of the transmitters of the FSN is printed on the terminal. If the identification of the transmitter received can be decoded, it will be shown at the bottom line of the Technical Data Widget.
The periodicity of the search for the data defining the position of the transmitter received can be set by adding a line to the .qt-dab.ini file
tii_delay=xxx
where xxx is the number of seconds. Default of the delay is 20 seconds.
In some cases, in some periods of listening, the sound is (or at least seems) interrupted. There are two different causes for this
First of all the incoming signal is weak and audio packages do not pass the many controls that are executed. This shows in the widget "technical data", not all the colored bars at the bottom are 100 percent green. An audio package represents 24 milliseconds of audio, loss of a few packages leads to an interruption of the sound.
A second reason has to do with system parameters. Too small a buffersize in the audio driver causes too high a frequency of calls to a callback function. In Linux this shows by an underrun reported by the alsa sound system. The buffer size can be set (in multiples of 256 audio samples) by the value of "latency" in the ".ini" file. The default value is 1.
On my RPI 2 - with Stretch - latency=2 works best.
Copyright (C) 2013, 2014, 2015, 2016, 2017
Jan van Katwijk (J.vanKatwijk@gmail.com)
Lazy Chair Computing
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.