Qt-DAB-7.2
About Qt-DAB
Qt-DAB is software for Linux and Windows, and can be compiled for MacOS and Raspberry Pi. It is used for listening to terrestrial Digital Audio Broadcasting (DAB and DAB+).
Of course, as for previous versions, for the current version,
Qt-DAB-7.2, predefined executables - for Linux an AppImage, for Windows
an installer - are (or will be) available.
Table of Contents
What is new in Qt-DAB-7.2
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In Qt-DAB-7.2 qwt is not used anymore for the “scopes”. The “compass” on the display for showing transmitters was a widget in Qwt and is not (yet) reimplemented in Qt-DAB and not visible.
The feature clicking with the right hand mouse button on the scopes remains, i.e. in three clicks you can set (1) background color, (2) grid color and (3) color of the curve;
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Qt-DAB-7.2 is developed using Qt6 but can be compiled without problems using the Qt5 framework using “qmake -qt5” for generating a makefile. The CMakeLists.txt file for using cmake contains some Qt6 dependencies;
In QtDAB-7.2 some GUI elements were changed:
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The “waterfall” disappeared: the GUI of a running version of Qt-DAB is sufficently limited in size that it can be shown - including the other windows - on my laptop screen.
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the progressbars on the technical window are replaced by simple indicators telling just whether the processing is OK.
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the main window contains a button channel view that - when touched - shows in a separate window an overview of the channels in the current database.
Windows and scopes
In the latest releases of 6.10 the dump button was already moved from the configuration window to the main window (the button implemented by a click
on the right hand button on the mouse on the ensemblename). Furthermore,
when dumpimg, a small window is shown that remminds the user that dumping is going on.
In Qt-DAB-7.1.1 some buttons were added to the main window.
The selector of the list of audio devices was traditionally shown as combobox in the configuration and control window,
now it is a separate small window, the visibility of which id controlled by a button on the main window.
Some other buttons are just replaced on the main window.
The main window is visisble as long as the program runs.
The left (almost) half is mainly reserved for selecting channel and service.
* the top line, displaying the ensemble name implements as clickable item as well
* clicking with the left mouse button, controls the visibility of the content table;
* clicking with the right mouse button control **dumping** the input.
Clicking on a service name selects the service with that name:
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in ensemble mode and in favorite mode, this might involving a channel switch which may take a few seconds;
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in ensemble mode, clicking with the right hand mouse button on an audio service other than the currently selected one, starts the service as background service;
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in ensemble mode the bottom part of the left half contaims next to the next and previous selectors for the services, a channel selector and a mode selector.
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in favorite mode no channel selector is available and the channelview button is meaningless.
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in file mode obviously only the services of the recording are shown and neither a mode selector nor a channel selector are visible. Furthermore, the channelview button is meaningless.
- the channelview button controls the visibility of the channeldisplay. The display shows an overview of the channels in the current database.
Clicking on a line in the channeldisplay has the same effect has clicking on the channelselector.
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The icons on the top line behave as in previous versions, i.e. the yellow one controls the visibility of the Qt-DAB-files directory (folder), and the
small blue one controls the visibility of the device list.
On the second line the “book style” icon controls the visibility of the
technical window, and the icon with label EPG, is shown in case
an EPG/SPI service is detected in the currently selected channel (Note that
the EPG/SPI service is NOT shown in the services list.)
If an EPG service is detected on starting a channel, Qt-DAB will attempt to start the service as background task. Data decoded by the EPG/SPI handler will be stored in a separate directory that is itself stored in the user’s Qt-DAB-files directory.
EPG/SPI data may consist of two parts:
- icons for services. If on selecting a service an Icon is detected in the user’s Qt-DAB-files directory, the Icon is made visible and takes the place of the short name of the service, both on the main window and the technical details window.
- Electronic Program Guide Data.
Touching the EPG icon make a small window visible, the timetable list.
The list shows the entries in the ensemblelist, coloured green is
timetable data for the service could be detected, red otherwide.
Touching in this list on a green entry, shows yet another window, with
time table data.
(Note: our NPO is not that advanced that it provides EPG/SPI data, so the
development and testing uses file input).
Note however, that in general it may take some time before sufficient EPG/SPI data is read in for the above mentioned functionality to be operational.
SNR
Clicking with the mouse on the SNR icon on the main window controls
the visibility of the snr-window. The snr-window shows the SNR of the current signal over time.
The setting is such that the screen shows app 2 minutes of subsequent snr measurements. It was - long time ago - included when I was exercizing different antenans.
Muting a signal
Clicking on the speaker symbol controls muting the audio signal.
If set, a counter appears telling the remaining mute time. The (maximum) mute time can be set on the configuration and control window. Of course, clicking on the speaker symbol when muting is “on”, turns it off.
The dynamic label.
The dynamic label shows below the slide space. Clicking with the right hand mouse button on the text shows a (very) small menu which allows saving (part of) the text. There are two other ways to save the dynamic label text or a part of it
- by selecting the dllText button on the configuration and control window;
- by selecting the save titles option in the configuration and control window. This latter option will work if the service supports DL2.
Technical window
The technical window shows - as the name suggests - technical details of
the selected audio service.
New is that - if available - the icon of the selected service is shown.
As said, the progress bars disappeared: indicators tell whether
or not the steps in the transformation from raw data to audio are successfull.
Essentially, if all indicators are green there should be sound.
Some buttons were moved from the configuration and control window tothe main window, resulting in two rows of buttons.
For each of the buttons a tooltip gives more details on the functionality controlled by that button.
The buttons:
- the buttons labeled controls, spectrum just control the visibility of the configuration and control resp. the *spectrum scope window;
- the buttons scan, “audio” and “device” control the visibility of windows to control scanning, selection of the audio channel, and controlling the selected device.
- the button labeled http controls the http handler with which the transmitters detected can be made visible on a map;
- the button labeled reset stops and restart processing;
- the button labeled eti controls the eti-processor, i.e. a processor with which the input can be transformed into “eti” compliant data files;
The bottom line
The bottom line of the right half of the main window may show a transmittername. If the software detects the TII data it will show the name of the transmitter with the strongest signal here.
Clicking on the line shows a table with the names of all transmitters detected.
As mentioned, it was felt that the waterfall did not add much to the understanding of the characteritics of the signal, and it was removed from the window.
The spectrumscope show on its left side six different “scopes”.
Note that for each of these scopes the coloring may be set
Clicking with the right hand mouse button on the scope, shows a small window on which *three colors can be selected:
- the first selected color is the one for the background; I prefer black
- the second selected one is the color for the “grid”,
- the third selected one is the color for the data line.
The spectrum
The spectrum of the incoming DAB signal is shown.
To the right of this spectrum, one sees the
signal constellation, i.e. the mapping from the complex (i.e. “IQ”) signals
resulting from the decoder, onto their real and imaginary components. If the selector labeled “ncp” is set, the centerpoints of the 4 lobs is shown.
Below the constallation widget the name of the current channel as well as its frequency is shown.
Below the “scope” area, some quality indicators of the DAB input signal are shown:
- the computed correction on the frequency of the incoming signal, applied to the signal;
- the remaining freq error (in Hz) after applying the correction;
- the SNR, i.e. the Signal-Noise Ratio in dB;
- the time offset, the (relative) resulting error in sampling time in Hz;
- the clock offset, telling the offset in the samplerate in Hz;
- the IQ unbalance, i.e. the (average) difference in strength between the I and the Q part of the DAB input signal;
At the bottom of the window from left to right
- a button controlling rhw visisbility of a small panel showing carriers;
- a sync indicator, green indicates that the software is synchronized with the incoming sample stream (i.e. time synchronization);
- a FIC indicator, telling the (average) successrate of decoding the FIC part of the DAB frames (i.e. the data that implements a kind of “catalog” that describes the payload);
- a BER, Bit Error Rate, telling (on average) how many input bits were
wrong (and were corrected), per 1000 input bits (lower is better) when processing the FIC;
- a MER, Modulation Error Rate, indicating the quality of the input signal (higher is better);
The ideal form of the spectrum and the signal constellation as shown in the
picture above is not often seen with real inputs.
The correlation
Correlation is used to identify the precise input sample in the input stream
where the (relevant) data of the frame starts.
The picture shows more than one peaks, i.e. the signal from
more than one transmitter is received (after all, the same DAB (DAB+) signal is transmitted by a pretty large number of transmitters);
The software chooses either the largest peak, or - if selected - the
first peak one larger than a threshold. A setting on the configuration window controls this.
The null scope
A DAB signal is received as a sequence of samples, and can be thought to
be built up from frames (DAB frames) where each frame consists of 199608 consecutive samples.
The amplitude of the first app. 2500 samples is (almost) zero, the NULL
period. The NULL scope shows the samples in the transition from the
NULL part to the first samples with data of a DAB frame.
It shows that samples 504 and up in the first data block are used.
The TII scope
In reality the NULL period is - in most cases - not completely
without signal, each second NULL period may contain
an encoding of the TII (Transmitter Identification Information) data.
The TII scope shows a condensed form of the spectrum of the data
in the relevant NULL period, the TII data is encoded as a 4 out of 8 code. Indeed, four larger (and four smaller) peaks can be seen in the picture. In this picture the pattern shown is 0x1e.
The DAB definition provides tables to map the recognized patterns
on to two 2 digit numbers, these numbers are used to identify the transmitter in a database, available in Qt-DAB.
The channel scope
The picture shows the channel response on the amplitude, and
the red line, i.e. the channel effects on the phase of the samples.
The picture clearly shows two larger and a few smaller peaks.
The bits scope
The front end part of the software output “soft bits”, encoded as values in the range -127 … 127. Other parts of the software take soft bits in and - using visterbi decoding and in some case reed Solomon error repair - output “hard bit”,
i.e. “1” and “0” values.
The carrier scope
As an option - visiblity controlled by the nutton labled carriers, a panel is added with a scope showing carriers.
In the current selection there is
- the NULL period with TII data;
- the NULL period without TII data;
- the carriers of the sync block (i.e. datablock 0);
- mean values of the carriers during decoding;
- the sigma (i.e. average squared distance to the center) of the carriers.
Configuration and control
The configuration and control window is completely redesigned.
Some selectors, buttons and checkboxes are removed, as mentioned the functionality is moved to (mainly using right hand mouse clicks) the main window.
Settings for the http and tpreg port, as well as the setting for the home position can now be set on the configuration window.
In the previous version, a selector mapview was added, that selector
is now placed in a line with other http related settings.
Since the software - on startup - always loads a database, i.e.
if one can be found in the user’s how directory that one, otherwise a default version, there was no need for selector for loading a database.
New are selectors labeled load selection and update check.
If the load selection selector is set, on program startup
a small menu shows, showing options to create a new database next to or instead of the default one.
Also new is a checkbox that - when set - instructs the software to check on program startup on the availability of a new version of Qt-DAB.
Handling packet and background services
DAB (DAB+) supports next to audio services also packet services. The EPG/SPI
service (if available) is an example: Qt-DAB starts automatically a backend interpreting the EPG/SPI data in a separate thread as background task, invisible
to the user.
While the default setting in the configuration window in Qt-DAB is to show
only audio services, the “audio only” setting can be “unset”, and
the audio services and - if available - the data services are shown.
Selecting a packet service is the same as selecting an audio service,
just clicking on it starts processing.
However, running a packet service is usually rather boring,
since there is not much to be seen or heard, that is why
Qt-DAB akways starts a packet service as background task.
Starting a packet service is simply by clicking on the name, same
as for audio services.
To avoid confusion, if the “audio only” selector is “unset”, only the services of the currently selected channel are shown, including the data services.
Obviously, when switching to another channel, the service interpretation stops.
Most package services contain some form of TPEG data,
which is usually encoded; Qt_DAB is unable to interpret the TPEG data
and Qt-DAB restricts itself to compile the TPEG frames
and send the data as UDP packet to an IP port (default 8888, but can
be set in the configuration window).
The sourcetree contains in the directory helpers/tdc-client a simple
reader for just reading udp packets (with no further interpretation at all).
Manually stopping a background service is possible,
a separate facility was created to stop such a service.
For that purpose, a small window can be made visible showing all running
backends (starting an audio service in the background shows the window,
its visibility is controlled by clicking on the number of services as shown
in the configuration and control window)
The number “5”, displayed in the process counter,
tells that there are 5 backends running.
(Note that the NPO and other Dutch broadcasters do not provide EPG/SPI
or other packet services, so the example is using a recording).
The figure shows that 5 services are running, the “Mode” indicator set to 1
tells the task is running in the background.
The picture shows an audio service, Dlf which carriers a
secondary service, DlfTXT.
Secondary services are also running in the background.
Touching the name of the service in this control window that is running in the background stops that service.
Note that it is also possible to run audio services found in the currently
selected channel in the background. The audio - for DAB mp2 format, for
DAB+ aac format - is written into a file that carries
name of the service combined with the date.
Click with the right hand mouse button on the name of an audio service
in the services list, and the decoding is started.
Manually stopping the service is by clicking again on the servicename.
Devices and device support
In the current set up, Qt-DAB supports 6 types of (physical) input devices,
some network input, and file input in some common formats.
- DABsticks (RTL2838U or similar), with separate libraries for the V3 and V4 versions of the stick in the precompiled Windows versions;
- All SDRplay SDR models (RSP I, RSP 1A and 1B, RSP II, RSP Duo, RSP Dx and RSPDxR2), with separate entries for the v2 and v3 library. New is extended support for the SDRPlay RspDuo. Tuner selection (and tuner 2 is connected to a port with biasT support) is now operational;
- a special entry exists for the SDRplay RSPDuo, one for running both tuners simultaneously;
- HACKRF One;
- Airspy, including Airspy mini (be aware that AirspyHF is not able to provide the samplerate required for DAB);
- LimeSDR;
- Adalm Pluto;
- untested UHD (due to lack of equipment)
Apart from the untested UHD device, support for these 6 device types is
commonly included in the precompiled versions.
It was noted by users running Qt-DAB on Windows that,
when using the support library for the V4 version of the RTLSDR (aka DABsticks) devices with a V3 device connected, the software seemed rather deaf.
To accommodate that, there are in the Windows peecompiled version two device entries, one supporting the V3 versions of the DAB sticks, the other for the V4 versions.
For the Windows version(s), the device libraries for almost all configured devices are provided in the installer.
The exceptions are the SDRplay and Pluto devices.
For Linux users, Ubuntu provides the required libraries for Pluto in a repository (i.e. libii0 and libad9361), for e.g. Fedora the support seems to stop at F33.
Qt-DAB also supports input using a network:
- an rtl_tcp server connected to an RTLSDR device.
- a spyServer (both 8 bit and a 16 bit version), i.e. from AIRSpy devices and RTLSDR devices.
- (NEW) is support for using the SDRconnect program as “input device”.
Be aware that when using SDRconnect, Qt-DAB processes input with a rate of 2048000 Samples/second. When connected over a network to the SDRconnect server,
it sends - with a samplerate of 2000000 (which is converted to the required rate of 2048000), 4 bytes per sample over the network. My wifi cannot handle that.
The same restriction applies to using the other servers.
The rtl_tcp server sends 2 byte samples, i.e. a payload of 4096000 bytes per second; the 16 bit spyServer sends 4 byte samples (with an even higher rate), all leading to a transmission rate that a regular WiFi cannot handle.
Qt-DAB furthermore supports
- Soapy (Linux only, not included in the AppImage), a renewed Soapy interface driver is even able to handle other samplerates than the required 2048000 (limited to the range 2000000 … 4000000).
In Qt_DAB-6.10 the soapy driver was renewed and now shows a
deviceselector when more than a single soapy-supported device is seen.
Furthermore, soapy now supports xml (i.e. “.uff”) files to be written,
although not in native format.
Qt-DAB obviously supports:
- reading (and writing) “.sdr” type files from the input, where “.sdr” type is a form of “.wav” file with IQ samples with fixed inputrate of 2048000 samples per second. Qt-DAB generates such files. As an extension to classical RIFF files that are limited to 4 Gb, Qt-DAB is able to handle (i.e. generate and read)
“.wav” files with a size larger than 4 Gb, their type is BW64.
The device window gives information on the “type” of the file i.e. RIFF or BW64.
When reading input from an “.sdr” file that was generated by Qt-DAB
both the name of the SDR device as well as the channel frequency of the reception is displayed as shown in the pictures above.
-
reading prerecorded dump rtlsdr type “raw” (8 bits) files. The RTLSDR device handlers show a button “dump” for dumping the raw input into a “.raw” file.
-
reading (and writing) so-called “xml” files, i.e. a file format preserving the precise structure of the input samples. All device handlers show on their device window a button to control dumping the unmodified input into an xml file (e.g. for the Airspy this means with a samplerate of 25000000 or 3000000). Note that there is no 4Gb limit for xml type files.
Scan control
A separate window - visible under control of the scan button on the
main window - provides full control on scanning. Qt-DAB provides different scanning modes:
- scan to data, i.ekeep on scanning until a channel with DAB data is detected;
- single scan, i.e. a scan from channel 5A to 13F,
- and scan continuously.
New is the spinbox, at the left side with the default value 20. The value of this spinbox tells that if a channel is encountered with SOME DAB data, the
software will be tuned to that channel for the number of seconds specified
to collect DAB data. As said, the default value is 20 (seconds),
increments are 20 (seconds).
- With single scan, i.e. a (single) scan over the channels of the band, a listing is produced of (the contents of) all ensembled encountered. In the scan window the channels where data was found, and the transmitters found for these channels, are given, as shown in the above picture.
- With scan to data scanning starts and continues until a channel is detected that carries DAB data (or scanning is stopped by touching the stop button).
- With scan continuously, i.e. scanning until stopped by the user, a single line is shown for each ensemble encountered, and - as the name suggests - scanning goes on until stopped by the user.
To allow skipping given channels when scanning, Qt-DAB supports the notion of a scantable, a table in which channels can be marked for skipping.
Next to a default scantable - which is stored in the users “.ini” file,
scantables can be created as separate files and read-in when required.
The show button controls the visibility of the scantable, scantables
can be loaded and stored in either the “.ini” file (use the “…default” buttons, or can be kept as xml file on a user defined place (the other load/store buttons).
The table at the bottom of the window is just for convenience, on scanning it displays the channel name being scanned currently, the ensemble name encountered and the number of services detected in the ensemble. Only for scan single the
transmitters that were identified are shown as well.
Displaying TII data
As mentioned, transmitters (usually) transmit some identifying data, the TII (Transmitter Identification Information) data. Qt-DAB uses a database (gratefully made available by “www.fmList.org”) to map the decoded TII data to name and location of the transmitter.
In recent versions, a copy of that database is included the precompiled
versions which is automatically loaded if no database can be found in the user’s home directory.
A fresh copy of that database can be installed in the user’s home directory
by a small utility, a db-loader, precompiled for Windows and Linux-x64.
The db-loader installs the database, file “.txdata.ti” in the user’s home directory, that is where Qt-DAB expects a database - with that name - to be found.
The configuration and control window contains a button to load the
database from the user’s home directory into the program.
Alternatively (and for other computing environments) one can download a
reasonably up to date copy of the database from the directory helpers
in the Qt-DAB repository.
Unpack the zipped file “tiiFile.zip” and name it “.txdata.tii” in the
home directory.
Qt-DAB has as said - on the main window - a button labeled http,
when touched, a webserver is started with on it a map centered around the
home position, that - when running - shows the position(s) of the
transmitter(s) received.
(Note that Qt-DAB is set to have a default home location -
somewhere in Amsterdam - that - together with default database - allows the
software to handle TII data and show the result of decoding on a map).
It is advised to update the user’s home location, the configuration
and control window contains entries to specify a latitude and a longitude.
The picture shows the channels I receive with a simple whip next to my “lazy chair”. Of course, using a more advanced antenna. more transmitters show, as seen on the picture below (courtesy of Herman Wijnants)
The webbrowser listens to port 8080. By default, the “standard” browser
on the system is activated. The configuration and control window
contains selector changing the port as well as turning the automatic
activation off.
NEW is the possibility of saving the data of the transmitters that are
shown on the map into a file and show the transmitters (or a selection)
on a map off-line.
The configuration window contains a selector that - when set -
tells the software to save the map contents into a file.
For that purpose, a small utility is available. The utility allows
reading in a generated map file, and displaying it, per country,
per channel, per ensemble or completely.
Journaline data
While (again) not in the region where I live, in some countries (Germany) DAB services are sometimes augmented with Journaline data. This data is - at least in the examples I have - transmitted in a subservice as shown in the picture
Qt-DAB uses the NewsService Journaline ® Decoder software from Fraunhofer IIS Erlangen in a slightly modified form (all rights gratefully acknowledged).
(Categorie names with an asterisks attatched show that new data is available)
Installation on Windows
For Windows an installer can be found in the releases section of this repository
Currently, there might be two versions, one with the name ending in -scalar,
the other one with the name ending in -avx. As mesntioned earlier,
the suffix tells whether or not avx2 instructions are used in
some of the computations or not. Older CPU’s do not support these
instructions.
The installer will install the executable as well as required libraries,
although for both SDRplay devices (when used) or for the Adam Pluto (when
used), one has to install libraries from the provider of the device (see below).
Installation on Linux-x64
For Linux-x64 systems, an appImage can be found in the releases section of
this repository
As for Windows, two versions might be available, one with and one without use of avx2 instructions.
The appImage contains next to the executable Qt-DAB program, the required interface libraries but not the support libraries for the configured devices. If you want to use a physical device - e.g. a DABstick, an SDRplay, or an AIRspy you need to install the driver libraries for the device as well.
Software for device support
For using an SDRplay device one should download the - proprietary - driver software from the SDRplay site. Note that while Qt-DAB has a device entry for
the “old” 2.13 library, that library does not support
the newer SDRPlay device model such as the SDRPlay 1B, the SDRplayDx
and the SDRPlay Dx-II. Use the 3.XX library instead.
The libraries can be found on the website of SDRplay
For using an AIRspy or a Hackrf device the Windows Installers contain support libraries. For Linux, the Ubuntu (and bullseye repository for the RPI)
the repository contains appropriate software.
For using an RTLSDR device the Windows Installers contain support libraries.
For Linux, the Ubuntu (and bullseye) repositories do provide a package. However, using that package one needs the
kernel module to be blacklisted, see e.g.
Personally, I prefer to build a version of the library myself, installation is easy, see:
For using the LimeSDR device the Windows Installers contain support libraries.
For Linux I went back to the sources and compiled the
support library myself, see:
For installing the support software for the Adalm Pluto for both Windows and
Linux I followed the instructions on
Note that Ubuntu releases provide libraries for supporting the Pluto.
Building an executable: a few notes
As mentioned, Windows an installer, for Linux an AppImage is available.
Since the sources are available, it is certainly possible to
build and executable.
I am doing the development on a Fedora box, but I am building the AppImage
on an Ubuntu 22 VM.
For Windows, I have installed Mingw64/MSYS and build the Windows version
on it.
It is strongly advised to use qmake/make for the compilation process,
the qt-dab-6.9.pro file contains (much) more configuration options
than the CMakeLists.txt file that is used when using cmake.
Note that the scheme presented below is applied when building the AppImage
on Ubuntu 22, and the Windows version using MSYS/Mingw64.
For other distributions (or later Ubuntu versions), names of library
packages may be different. Note that in all cases, the development versions (i.e. the versions with the include (“.h”) files) are required.
For creating an executable on and for Windows the easiest approach is
to install msys/mingw and follow the process as sketched.
Using an MS toolchain on Windows was for me (I tried it once) not successfull
and, since I develop compile and cross compile on a Fedora Linux box, my interest in developing ON windows is less than zero.
Step 1
- :information_source: In the repository, the sources for the current Qt-DAB version (6.10) are in the directory “qt-dab/ sources”. All sources and include files are found in this directory". The “.pro” file is - as is the CMakeLists.txt file - in the “qt-dab” directory.
The qt-dab repository contains a file “structure.md” in which the structure is explained.
Running with the “.pro” file as in the repository, the resulting Qt-DAB executable is stored in a directory “/linux-bin” when compiled for Linux and in a directory “/d/systems/qt-dab/linux-bin” when compiling
for windows (using mingw64). You probably want to modify it.
For building the AppImage on Ubuntu 22, I load the required libraries as given below:
- sudo apt-get update
- sudo apt-get install git
- sudo apt-get install cmake
- sudo apt-get install qmake6
- sudo apt-get install build-essential
- sudo apt-get install g++
- sudo apt-get install pkg-config
- sudo apt-get install libfftw3-dev
- sudo apt-get install portaudio19-dev
- sudo apt-get install zlib1g-dev
- sudo apt-get install libusb-1.0-0-dev
- sudo apt-get install mesa-common-dev
- sudo apt-get install qt6-base-dev
- sudo apt-get install qt6-multimedia-dev
- sudo apt-get install libcurl4-openssl-dev
- sudo apt-get install libfdk-aac-dev (read the note below)
- :information_source: An issue is getting the required qwt library. On my Fedora box, a qwt-6.2 version for Qt6 is available, Ubuntu does not provide
the Qt6 version for qwt. I had to install it myself as shown below
- Download qwt-6.30 from “https://sourceforge.net/projects/qwt/files/qwt/6.3.0/”;
- follow the instructions (i.e. unzip, cd to the unzipped folder) and adapt the config file to your likings;
- building is then simple (takes some time though): “qmake6 qwt.pro”, “make”;
- install the library (“sudo make install”) and inform the loader “sudo ldconfig”;
- Note that the default for installation is “/usr/local/qwt/6.3.0”, adjust the PATH settings accordingly.
- :information_source: While the libfdk-aac-dev package in both Fedora and Ubuntu 24 seems to work fine, I had some problems with the package from the repository in Ubuntu 22. For the AppImage, built on Ubuntu 22, a library version was created from the sources to be found as github repository:
The sources contain a CMakeLists.txt file, building and installing is straightforward.
Alternatively, one could configure for libfaad, change the configuration to
- CONFIG += faad
- #CONFIG += fdk-aac
and install the libfaad package
- sudo apt-get install libfaad-dev
- :information_source: If “soapy” is configured, libsamplerate (both the library and the include files) should be installed on the development system. Of course the various Soapy libraries as well.
Step 2
While there are dozens of configuration options, take note
of the following ones:
-
:information_source: A new viterbi decoder is part of the sources, one may choose between this “new” one and the “older” version derived from the spiral project.
CONFIG += viterbi-scalar
#CONFIG += viterbi-sse
#CONFIG += viterbi-avx2
#CONFIG += spiral-sse
#CONFIG += spiral-no-sse
If unsure, choose either “viterbi-scalar” or “spiral-no-sse”
While the cou load is somewhat higher when using a scalar version,
the implementation does not use any special CPU specific instructions.
Default is there using a scalar version of the viterbi decoder, which works just fine.
In the latter case, all computations in the “front end” are done with double precision arithmetic.
-
:information_source: Devices like SDRplay, AIRspy, RTLSDR dongle, LimeSDR,
HackRf and Adalm Pluto can be included in the configuration even if no support library is installed. (Note that including Soapy requires Soapy libraries to be installed, so this does not apply for Soapy). Qt-DAB is designed such that on selecting a device in runtime, the required functions from the device library are linked in.
-
:information_source: The Soapy library used in Ubuntu 22 (used for tessting the AppImage) is incompatible with Soapy libraries installed on other versions of Ubuntu and other Linux distributions, therefore Soapy is NOT configured
for inclusion in the AppImage.
-
:information_source: Uncomment the line DEFINES += __THREADED_BACKEND if you intend to have more than one backend running simultaneously. E.g. activating the automatic search for an EPG service starts a separate service if such a service is found. With this setting each backend will run in its own thread.
Step 3
Run qmake (variants of the name are qmake6, qt6-qmake, etc),
which generates a Makefile and then run make. Compiling may take some time.
Use make -j XX for speeding up the build process, with XX the amount
of parallel threads used. Of course, qmake will complain if not all
required libraries can be found.
If all libraries were found, this step should result in an executable.
Step 4
Use the database downloader (for Windows and Linux available as
precompiled item) to download a fresh copy of the database. Or download a
copy of the database from the repository.
A copy of the database is part of the repository. The directory helpers
contains a file “tiiFile.zip”, unpack the zipped file and store the result
in your homedirectory (folder).
If Qt-DAB does not see the database, it will just function without mapping TII data onto names and locations.
A user compiled Qt-DAB-6.9, on and for an RPI, and met the following issues:
Once I had downloaded the qt-dab-master from the code page,
installed all the libraries listed in the Readme on the code page,
and then installed the new qwt 6.30 as instructed,
I had a problem getting the .pro file to recognise the new qwt version.
This was because on the pi it installs to /usr/include.
So I changed the .pro file as follows:
Line 433
INCLUDEPATH += /usr/include
!mac {
INCLUDEPATH += /usr/include/qwt-6.3.0/lib
#correct this for the correct path to the qwt6 library on your system
#LIBS += -lqwt
equals (QT_MAJOR_VERSION, 6) {
LIBS += -lqwt-qt6
}else{ LIBS += -lqwt-qt5
However I still could not get the qwt recognised so further changes were needed, this time to the Modules folder.
To do this, I went to the qt-dab-6.9 folder in the qt-dab-master, and then opened the folder cmake. Then Modules.
Found the relevant FindQwt file and made the following changes:
find_path(QWT_INCLUDE_DIRS
NAMES qwt_global.h
HINTS
${CMAKE_INSTALL_PREFIX}/include/qwt
${CMAKE_INSTALL_PREFIX}/include/qwt-qt6
PATHS
/usr/local/include/qwt-qt6
/usr/local/include/qwt
/usr/include/qwt6
/usr/include/qwt6-qt6
/usr/include/qt6/qwt
/opt/local/include/qwt
/usr/include/qwt-6.3.0
/sw/include/qwt
/usr/local/lib/qwt.framework/Headers
/usr/local/lib/qwt-qt5/lib/framework/Headers
/usr/include/qwt-6.3.0/include
)
if (APPLE)
set(CMAKE_FIND_LIBRARY_SUFFIXES " " " .dylib" ".so" ".a ")
endif (APPLE)
find_library (QWT_LIBRARIES
NAMES qwt6 qwt6-qt6 qwt-qt6 qwt
HINTS
${CMAKE_INSTALL_PREFIX}/lib
${CMAKE_INSTALL_PREFIX}/lib64
PATHS
/usr/local/lib
/usr/lib
/opt/local/lib
/sw/lib
/usr/local/lib/qwt.framework
/usr/local/lib/qwt-qt6/lib/framework
/usr/include/qwt-6.3.0/lib
)
With these settings Qt-DAB could be compiled
Using user specified bands
While it is known that the DAB transmissions are now all in Band III, there might be situations where it is desirable to use other frequencies.
Qt-DAB provides (Unix/Linux builds only) the opportunity to specify
one’s own band. Specify in a file a list of channels, e.g.
one 227360
two 220352
three 1294000
four 252650
and pass the file on program start-up with the -A command line switch. The channel name is just any identifier, the channel frequency is given in kHz. Your SDR device obviously has to support the frequencies for these channels.
Copyright and acknowledgements
Copyright (C) 2016 .. 2025
Jan van Katwijk ([email protected])
Lazy Chair Computing
Copyright of libraries used - Qt, qwt, fftw, portaudio,
libusb-1, libfaad, libfdk-aac, - is gratefully acknowledged.
In developing Qt-DAB many people have contributed, special thanks
to
* Herman Wijnants,
* Andreas Mikula,
* and Jarod Middelman
for continuous feedback and suggestions, and
* Rolf Zerr (aka old-dab),
* Stefan Poeschel,
for important code contributions.
Qt-DAB is distributed under the GPL V2 library, 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.
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