dabradio

dabradio is a Software for Windows, Linux and Raspberry Pi for listening to terrestrial Digital Audio Broadcasting (DAB and DAB+). It is the little brother of Qt-DAB.

NEW: a script to build an executable on an rpi

In order to ease building an executable on a Raspberry 2 or 3, a script, "script-rpi.sh" is available that will do all installations of required libraries, and build an executable for an executable "dabradio-1.0", configured for DABsticks and sdrPlay devices.

The script will load sources for a DABstick handler and build and install the library. An installer for the sdrPlay devices can be obtained from "www.sdrplay.com".

The script assumes an installation of Stretch on the RPI device, it is assumed "git" is installed to fetch the source package.

sudo apt-get install git
git clone https://github.com/JvanKatwijk/dabradio
cd dabradio
chmod 777 script-rpi.sh
./script-rpi.sh

Note that the installer for the rtlsdr handler will create an "udev" file (in "/etc/udev/rules.d"), that will be active only after a restart (or a restart of the udev subsystem).

During installations of the various packages, several times one has to acknowledge when asked for, so while it takes a few minutes it is wise to stay around.

The executable will be installed in the subdirectory "linux-bin".

Introduction
Features
Installation
Copyright

Introduction

dabradio is the little brother of Qt-DAB. The latter is kind of a research vehicle, with lots of options, most of them used by only a few. The need arose to have a smaller brother, just for tuning to and listening to DAB services.

dabradio and Qt-DAB share a lot of functionality, obviously. Nevertheless to avoid even more "ifdef"s in the code, it was decided to maintain separate GitHub repositories for each of them.

A feature specific to this implementation is that, rather than selecting a channel, the software maintains a list of channels that can be received. This list is maintained between program invocations, on program start up, these channels are scanned for services. Of course, the first time the program is started (or on a reset), all channels in the given band are listened to to see whether or not a DAB signal can be detected. If so, the channel is recorded.

The GUI does not provide buttons to select the Mode or the Band. Defaults are Mode 1 and the VHF Band III. In the ".ini" file (a file .dabradio.ini in the home directory of the user) the Mode can be set as well as the band (Since the DAB standard in 2016 simplified DAB (a.o) by just supporting Mode 1 in VHF Band III, a future version will omit the possibility of choosing band and/or mode).

The services are presented in a separate widget, for each service the widget contains some additional information.

Device selection is automated, if a device - which is part of the configuration - is connected, the software will detect that and connect to that device on program start-up. If more than one device is connected, one will be selected.

Features

DAB (mp2) and DAB+ (HE-AAC v1, HE-AAC v2 and LC-AAC) decoding
MOT SlideShow (SLS)
Dynamic Label (DLS)
(Almost obsolete) Both DAB bands supported (default VHF Band III, can be set in the ini file):
- VHF Band III
- L-Band (only used in Czech Republic and Vatican)
Scanning function (scanning over all channels in a given band and collecting all services)
Supports input from various devices:
- SDRplay (both RSP I and RSP II),
- Airspy, including Airspy mini,
- SDR DAB sticks (RTL2838U or similar), and
- HACKRF one.

Data services are not visible to the user, although MOT as subservice is - limited - implemented.

Especially with simple devices, as e.g. DABsticks, with poor antenna equipment, there is a chance that decoding and error correction fails, resulting in some hick ups in the sound output.

The most recent version now shows the successrate in Fib decoding as well as the successrate in audio decoding. In a decent setup, i.e. with a reasonable antenna, the successrate in the Fib decoding should be 100. If the successrate in the audiodecoding is less than 100, one might expect some gaps in the audio output.

Windows

For Windows, an installer is available in the releases section. The installer will aldo install - if not installed already - the library for SDRplay support.

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

Linux: Ubuntu/x64 and Stretch RPI2/3

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) as well as Debian/Stretch on the RPI2 and 3 have good support for Qt5 (note that contrary to Qt-DAB no use is made of the qwt library). For generating an executable under Ubuntu (16.04 or newer) or on the RPI 2/3 running under Stretch, THE FOLLOWING COMMANDS ARE IN A SCRIPT: build-script. It was tested on RPI2/3 running stretch. (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++ git cmake
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 
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

 git clone git://git.osmocom.org/rtl-sdr.git
 cd rtl-sdr/
 mkdir build
 cd build
 cmake ../ -DINSTALL_UDEV_RULES=ON -DDETACH_KERNEL_DRIVER=ON
 make
 sudo make install
 sudo ldconfig
 cd ..
 rm -rf build
 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 dabradio sources

git clone https://github.com/JvanKatwijk/dabradio.git
cd dabradio

Edit the dabradio.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.
Build and make

qmake dabradio.pro
make

You could also use QtCreator, load the dabradio.pro file and build the executable.

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

Configuring using the dabradio.pro file

Options in the configuration is to select or unselect devices.

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.

CONFIG          += dabstick
CONFIG          += sdrplay
CONFIG          += airspy
CONFIG          += hackrf

Audio samples are sent to an audio device using the portaudio library.

If you are compiling/running for an x64 based PC with SSE, then you could set

#CONFIG          += NEON_RPI2
#CONFIG          += NEON_RPI3
CONFIG          += SSE
#CONFIG          += NO_SSE

If you are compiling/running for an RPI2, and want to check whether or not NEON instructions can be used, you could set

CONFIG          += NEON_RPI2
#CONFIG          += NEON_RPI3
#CONFIG          += SSE
#CONFIG          += NO_SSE

If you are compiling/running for an RPI3, and want to check whether or not NEON instructions can be used, you could set

#CONFIG          += NEON_RPI2
CONFIG          += NEON_RPI3
#CONFIG          += SSE
#CONFIG          += NO_SSE

The safest way - always - is to set

#CONFIG          += NEON_RPI2
#CONFIG          += NEON_RPI3
#CONFIG          += SSE
CONFIG          += NO_SSE

Slightly slower since no the other two use specialized instructions in the viterbi decoding (which is quite heavy in DAB decoding)

Further in the ".pro" file, in the section labeled NEON, you could choose between compiler flags set for optimizing for the RPI2 or the RPI3 by commenting (or uncommenting) some lines

The default setting in the ".pro" file is NO_SSE, as is the case in the CMakeLists.txt file.

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 .. -DSDRPLAY=ON -DRTLSDR=ON -DAIRSPY=ON

will generate a makefile with support for three supported devices, the SDRplay device the AIRSPY device and the RTLSDR based dabsticks.

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.

SDRplay

The current set of sources provides support for the RSP-I and the RSP-II and the new RSP-1a, it is assumed that at least library version 2.09 is installed.

HACKRF one

The current set of sources provides support for the HACKRF One. It is assumed that a library is installed. Since support for HACKRF One is still slightly experimental, it can only be configured using the qmake/make installation route.

Qt

The software uses the Qt library, the CMakeLists.txt assumes Qt5, the dabradio.pro file can easily be changed to use Qt4.

Raspberry PI

The dabradio software runs pretty well on the author's RPI-2 ans 3 The average load on the 4 cores on the RPI2 is somewhere between 50 and 60 percent, on the RPI3B+ it is well below 50 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 releases section contains an AppImage developed under and for Raspbian Stretch on an RPI2 and RPI3. Note that libraries for the rtlsdr DABstick and/or the Airspy can be obtained from repositories for Raspbian Stretch. An API library for the SDRplay can be downloaded from sdrplay.com

Use is simple, install the libraries as needed, download the AppImage file, chmod 777 dabradio-ARM.AppImage to set the exec bit and run the program. Running is possible therefore withour compiling anything.

If you want to create your own executable, pls note that an optimal use of the 4 cores of the CPU can be makde by uncommenting (in the ".pro" file)

#DEFINES += __THREADED_DECODING.
#DEFINES += __THREADED_BACKEND

For the CMakeLists.txt file, uncomment

#add_definitions (-D__THREADED_DECODING -D__THREADED_BACKEND) #uncomment for the RPI

appImages for x64 Linux systems and RPI2/3

https://github.com/JvanKatwijk/dabradio/releases contains a generated appImage, dabradio-x64.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 an appropriate usb library, libraries to support either a dabstick (i.e. rtlsdr) or an Airspy are included in the appImage (the appropriate udev rules, i.e. rules to allow a non-root user to use the device through USB, will be installed by the execution of the appImage, that is why it will ask for your password. If you have installed the device of your choice, you can just cancel this request). If you want to run with an SDRplay, follow the installation instructions for the library from "www.sdrplay.com". All further dependencies are included. The appImage is just a self-contained single file which you have to make executable in order to run. It furthermore contains an -experimental- appImage for use under Stretch on an RPI2/3, dabradio-ARM.AppImage.

For more information see http://appimage.org/

Comment on some settings

Some values of settings are maintained between program invocations. This is done in the (hidden) file .dabradio.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.

A note on intermittent sound

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

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.

JvanKatwijk / dabradio