mSoma a Qt client for SomaFM

Wed, 07 Jul 2010 10:12:00 +0000

Andrea Grandi proposed me a few weeks ago to try and develop a client for SomaFM, a streaming radio with near 16 different channels, available for free. Indeed we wanted to try to develop an application for our cool Nokia N900 smartphone. Since this phone is now based on my beloved Qt framework, I accepted with much pleasure.

The really cool thing was that, by relying on the qt-mobility APIs (new Qt APIs for mobile application developers), we could enjoy cross-platform developing: all the code that I wrote for this player was tested and debuged on my computer, as a desktop application. Then, we deployed on the Nokia N900 and tried it there (and it worked seamlessly).

For instance, this are some screenshots of msoma running as a desktop application (in Linux in this case):

And this is a screenshot of the application running in the N900 (taken from Andrea's blog post):

Which is just a recompilation targeting Maemo (with this respect, the Nokia Qt SDK, based on QtCreator, is really helpful when developing).

Of course, this is the very first version of this application, and surely the UI should be different in the desktop application with respect to the cellphone version (in order to be more usable in the mobile devices). But, as it is, it's already enjoyable (but I may be biased ;)

Source code is available on Gitorious and it's always updated with latest version we're working on. If someone want to test the application, it's available in extras-devel repository ("msoma" under Multimedia section) of N900.

In case you want to use it as a desktop application, please remember that you need qt-mobility. I blogged about the installation of qt-mobility in Linux.

We really want to thank, Rusty Hodge, SomaFM's founder, who provided so many details about SomaFM for developing our application (and of course we thank him also for SomaFM itself :)

We look forward to receiving feedback, patches, suggestions, and help! :)

Our maemo profiles:

5 0

Building Qt-Mobility in Ubuntu

Fri, 18 Jun 2010 11:05:00 +0000

Lately I started to try to develop applications for the Nokia N900, and the Maemo platform uses my beloved framework Qt :)

In particular, Nokia started to develop the Qt-Mobility Framework. Quoting from their white paper:

The Qt Mobility Project presents a collection of related software frameworks and interfaces. The objective being to deliver new Qt APIs for mobile application developers. Using these new APIs, developers will be able to create cross-platform applications targeting Maemo, Symbian and other platforms. This suite of features also has components that will be desirable to all users, not just those with mobile devices, so Mobility has advantages even for the desktop user.

Thus, I wanted to try this project also on my Desktop (after all the intent of this framework is cross-platform development), and tried to compile qt-mobility on my Ubuntu/Kubuntu desktop. Unfortunately, I experienced many problems which now I seem to have solved, thus I'd like to share the steps to build qt-mobility from sources.

First of all, when installing qt-mobility after compilation, some files will be created in your current Qt installation. Thus, since I wouldn't want to spoil my qt installation from ubuntu packages, which is installed in system path, I downloaded the new qt framework 4.6.3 from the Nokia download site, and installed it in a path of my home: ~/usr/local/Trolltech/qtsdk-2010.03.

Then, I installed some packages that are useful to build qt-mobility and to enjoy media contents such as mp3 and videos, relying on gstreamer (not all these packages may be necessary, but after some tests, at least these packages will make things work):

sudo apt-get install libasound2-dev libbluetooth-dev libgstreamer0.10-dev libgstreamer-plugins-base0.10-dev network-manager-dev libxv-dev gstreamer-tools gstreamer0.10-plugins-base gstreamer0.10-ffmpeg w32codecs ubuntu-restricted-extras gstreamer0.10-plugins-good freeglut3-dev

Then, you need to get the sources of qt-mobility, and I got them from the git repository

git clone git://gitorious.org/qt-mobility/qt-mobility.git

However, you may want to get the stable sources (e.g., from qt-mobility download).
Since I'm a big fan of "shadow builds" which won't spoil your source directory, I built qt-mobility in another directory of my home, separate from the directory where I have the sources of qt-mobility (in this example the sources are in ~/install/qt-mobility): ~/build/qt-mobility/qt-4.6.3 (I specified the qt version I'm building qt-mobility with, since I may want to experiment with different qt versions):

cd ~/build/qt-mobility/qt-4.6.3
PATH=~/usr/local/Trolltech/qtsdk-2010.03/qt/bin:$PATH ~/install/qt-mobility/configure -examples -prefix ~/usr/local/Trolltech/qt-mobility > output.txt

Note that I temporarily change the PATH environment variable so that the configure script will use my local qt installation; I specify that I want to build the examples, and I redirect the output in a text file. This will also allows you to see possible errors during the configuration step (e.g., missing packages). Note also that I will install (once built) qt-mobility in my home directory in ~/usr/local/Trolltech/qt-mobility.

Once the configuration step is successful, you can start building qt-mobility and then install it:

make
make install

During the installation, if you take a look at the output, you will note that some files will be added to your qt installation, e.g.,

install -m 644 -p /home/bettini/build/qt-mobility/qt-4.6.3/features/mobility.prf /home/bettini/usr/local/Trolltech/qtsdk-2010.03/qt/mkspecs/features/
install -m 644 -p /home/bettini/build/qt-mobility/qt-4.6.3/features/mobilityconfig.prf /home/bettini/usr/local/Trolltech/qtsdk-2010.03/qt/mkspecs/features/

This way qt-mobility will be integrated in your qt framework (at least, this is what I presume).

Now, you can test your qt-installation by running an example (which was built and installed), for instance the player demo or the weather demo:

~/usr/local/Trolltech/qt-mobility/bin/player
~/usr/local/Trolltech/qt-mobility/bin/weatherinfo_with_location

Now, let's try to see whether we're able to use qt-mobility in our programs.

We'll try to compile a very simple qt program using a class from the qt-mobility framework (QVideoWidget), though we won't do anything with that (just to see whether we can build the application).

here's the files of our project

myvideowidget.pro

QT       += core gui

TARGET = myvideowidget
TEMPLATE = app


SOURCES += main.cpp\
       mainwindow.cpp

HEADERS  += mainwindow.h

CONFIG += mobility
MOBILITY = multimedia

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include 

class QVideoWidget;
class QMediaPlayer;

class MainWindow : public QMainWindow
{
   Q_OBJECT

public:
   explicit MainWindow(QWidget *parent = 0);

private:
   QVideoWidget *videoWidget;
   QMediaPlayer *player;
};

#endif // MAINWINDOW_H

mainwindow.cpp

#include 
#include 
#include 

#include "mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
   QMainWindow(parent)
{
   videoWidget = new QVideoWidget(this);

   setCentralWidget(videoWidget);
}

main.cpp

#include 
#include "mainwindow.h"

int main(int argc, char *argv[])
{
   QApplication a(argc, argv);
   MainWindow w;
   w.show();
   return a.exec();
}

now, you should run the qmake of your qt installation you've used to build qt-mobility, thus

~/usr/local/Trolltech/qtsdk-2010.03/qt/bin/qmake myvideowidget.pro

and then run make, hopefully you should get no error. Note that we haven't named our qt-mobility installation directory anywhere here; there's no need to, since your qt installation was modified by qt-mobility, so that qmake will set all the variables for include files and libraries also for the qt-mobility path! In fact, you should see these compilation command lines:

g++ -c -pipe -O2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_OPENGL_LIB -DQT_GUI_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -DQT_SHARED -I../../../../usr/local/Trolltech/qtsdk-2010.03/qt/mkspecs/linux-g++ -I../../myvideowidget -I../../../../usr/local/Trolltech/qtsdk-2010.03/qt/include/QtCore -I../../../../usr/local/Trolltech/qtsdk-2010.03/qt/include/QtNetwork -I../../../../usr/local/Trolltech/qtsdk-2010.03/qt/include/QtGui -I../../../../usr/local/Trolltech/qtsdk-2010.03/qt/include/QtOpenGL -I../../../../usr/local/Trolltech/qtsdk-2010.03/qt/include -I/home/bettini/usr/local/Trolltech/qtsdk-2010.03/qt/include/QtMultimediaKit -I../../../../usr/local/Trolltech/qt-mobility/include -I../../../../usr/local/Trolltech/qt-mobility/include/QtMultimediaKit -I/usr/X11R6/include -I. -I../../myvideowidget -I. -o mainwindow.o ../../myvideowidget/mainwindow.cpp
g++ -Wl,-O1 -Wl,-rpath,/home/bettini/usr/local/Trolltech/qtsdk-2010.03/qt/lib -Wl,-rpath,/home/bettini/usr/local/Trolltech/qt-mobility/lib -o myvideowidget main.o mainwindow.o moc_mainwindow.o -L/home/bettini/usr/local/Trolltech/qtsdk-2010.03/qt/lib -L/usr/X11R6/lib -L/home/bettini/usr/local/Trolltech/qt-mobility/lib -lQtMultimediaKit -lQtOpenGL -L/home/bettini/usr/local/Trolltech/qtsdk-2010.03/qt/lib -L/usr/X11R6/lib -lQtGui -lQtNetwork -lQtCore -lGLU -lGL -lpthread

Now you can enjoy qt-mobility in your desktop :)0 0

Planet Maemo: category "feed:d2a10b3e8055809a86b77053ec277953"

mSoma a Qt client for SomaFM

Building Qt-Mobility in Ubuntu