// fftcalc class is designed to treat with fft calculations
FFTCalc::FFTCalc(QObject *parent)
:QObject(parent){
// fftcalc is done in other thread
// so it cannot overload the main thread
processor.moveToThread(&processorThread);
// qRegisterMetaType is used to register QVector<double> as the typename for QVector<double>
// it is necessary for signal/slots events treatment.
qRegisterMetaType< QVector<double> >("QVector<double>");
// when the spectrum is calculated, setSpectrum function will comunicate
// such spectrum to Qt as an emitted signal
connect(&processor, SIGNAL(calculatedSpectrum(QVector<double>)), SLOT(setSpectrum(QVector<double>)));
// when the processor finishes the calculation, the busy condition is changed.
connect(&processor, SIGNAL(allDone()),SLOT(freeCalc()));
// start the processor thread with low priority
processorThread.start(QThread::LowestPriority);
// initially, the processor is not occupied
isBusy = false;
}
void BufferProcessor::run(){
// spectrum amplitude
qreal amplitude;
qreal SpectrumAnalyserMultiplier = 0.15e-3;
// tells when all chunks has been processed
if(pass == chunks){
emit allDone();
return;
}
// we does not calc spectra when array is too small
if(array.size() < SPECSIZE){
return;
}
// prepare complex frame for fft calculations
for(uint i=0; i<SPECSIZE; i++){
complexFrame[i] = Complex(window[i]*array[i+pass*SPECSIZE],0);
}
// do the magic
fft(complexFrame);
// some scaling/windowing is needed for displaying the fourier spectrum somewhere
for(uint i=0; i<SPECSIZE/2;i++){
amplitude = SpectrumAnalyserMultiplier*std::abs(complexFrame[i]);
amplitude = qMax(qreal(0.0), amplitude);
amplitude = qMin(qreal(1.0), amplitude);
complexFrame[i] = amplitude;
}
// audio spectrum is usually compressed for better displaying
if(compressed){
for (int i = 0; i <SPECSIZE/2; i ++){
/* sum up values in freq array between logscale[i] and logscale[i + 1],
including fractional parts */
int a = ceilf (logscale[i]);
int b = floorf (logscale[i+1]);
float sum = 0;
if (b < a)
sum += complexFrame[b].real()*(logscale[i+1]-logscale[i]);
else{
if (a > 0)
sum += complexFrame[a-1].real()*(a-logscale[i]);
for (; a < b; a++)
sum += complexFrame[a].real();
if (b < SPECSIZE/2)
sum += complexFrame[b].real()*(logscale[i+1] - b);
}
/* fudge factor to make the graph have the same overall height as a
12-band one no matter how many bands there are */
sum *= (float) SPECSIZE/24;
/* convert to dB */
float val = 20*log10f (sum);
/* scale (-DB_RANGE, 0.0) to (0.0, 1.0) */
val = 1 + val / 40;
spectrum[i] = CLAMP (val, 0, 1);
}
}
else{
// if not compressed, just copy the real part clamped between 0 and 1
for(int i=0; i<SPECSIZE/2; i++){
spectrum[i] = CLAMP(complexFrame[i].real()*100,0,1);
}
}
// emit the spectrum
emit calculatedSpectrum(spectrum);
// count the pass
pass++;
}
void FFTCalc::setSpectrum(QVector<double> spectrum){
// tells Qt about that a new spectrum has arrived
emit calculatedSpectrum(spectrum);
}
// constructor: warm up all stuff
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
//,audioInfo(QAudioDeviceInfo::defaultInputDevice())
{
// draws the ui
ui->setupUi(this);
// test for saving settings
QCoreApplication::setOrganizationName("Agostinho");
/** some settings attempt
*/
QSettings settings; /*!<aloha */
settings.setValue("alo","maria");
// defines sample size equals to spectrum size
sample.resize(SPECSIZE);
// threads are as separate processes running within the same
// program. for fft calculation, it is better to move it
// to another thread to make the calcs faster.
// moreover, it will not slow down the ui
// fftThread = new QThread(this);
calculator = new FFTCalc();
// calculator->moveToThread(fftThread);
// launches the new media player
player = new QMediaPlayer();
// starts a new playlist
playlist = new QMediaPlaylist();
// starts the playlist model
playlistModel = new PlaylistModel(this);
// tell playlistmodel where is the playlist
playlistModel->setPlaylist(playlist);
// attach the listView to the playlistModel
ui->listViewPlaylist->setModel(playlistModel);
// set current index to the first element
ui->listViewPlaylist->setCurrentIndex(playlistModel->index(playlist->currentIndex(), 0));
loadPlaylist();
// attachs the playlist to the player
player->setPlaylist(playlist);
// playlist plays in loop mode. It restarts after last song has finished playing.
playlist->setPlaybackMode(QMediaPlaylist::Loop);
// this allow the user to select the media it wants to play
connect(ui->listViewPlaylist, SIGNAL(doubleClicked(QModelIndex)),
this, SLOT(goToItem(QModelIndex)));
// if some metadata changed for media, display it somewhere
// it seems not work on windows
// but works for linux :)
connect(player,SIGNAL(metaDataChanged()),
this, SLOT(metaDataChanged()));
// the media status changed (new stream has arrived)
connect(player, SIGNAL(mediaStatusChanged(QMediaPlayer::MediaStatus)),
this, SLOT(mediaStatusChanged(QMediaPlayer::MediaStatus)));
// the user selected a new position on music to play
// perharps using some scrollbar
connect(this,SIGNAL(positionChanged(qint64)),
player,SLOT(setPosition(qint64)));
connect(player,SIGNAL(volumeChanged(int)),
ui->control,SLOT(onVolumeChanged(int)));
connect(player,SIGNAL(stateChanged(QMediaPlayer::State)),
SLOT(mediaStateChanged(QMediaPlayer::State)));
// that is the audio probe object that "listen to"
// the music. It will help with fft stuff
probe = new QAudioProbe();
// fft is delivered using a QVector<double> but
// signal/slot scheme does not recognizes this type by default
// therefore, we have to register it
qRegisterMetaType< QVector<double> >("QVector<double>");
// here goes the control unit event handlers
connect(ui->control, SIGNAL(playPause()), this, SLOT(playPause()));
connect(ui->control, SIGNAL(prev()), this, SLOT(prev()));
connect(ui->control, SIGNAL(next()), this, SLOT(next()));
connect(this, SIGNAL(playPauseChanged(bool)),
ui->control,SLOT(onPlayerStateChanged(bool)));
// when the music position changes on player, it has to be
// informed to the control unit to redraw it ui
connect(player, SIGNAL(positionChanged(qint64)),
ui->control,SLOT(onElapsedChanged(qint64)));
// fft goes here...
// if a new audio buffer is ok, we have to make some
// calcs (fft) to display the spectrum
connect(probe, SIGNAL(audioBufferProbed(QAudioBuffer)),
this, SLOT(processBuffer(QAudioBuffer)));
// when fft is available, we deliver it to
// the visualization widget
connect(this, SIGNAL(spectrumChanged(QVector<double>&)),
ui->visualizer,SLOT(loadSamples(QVector<double>&)));
// communicate the left and right audio levels...
// ...mean levels
connect(this, SIGNAL(levels(double,double)),
ui->visualizer,SLOT(loadLevels(double,double)));
// when fft is available, we deliver it to
// the visualization widget
//connect(this, SIGNAL(spectrumChanged(QVector<double>&)),
// ui->glVisualizer,SLOT(loadSamples(QVector<double>&)));
// communicate the left and right audio levels...
// ...mean levels
//connect(this, SIGNAL(levels(double,double)),
// ui->glVisualizer,SLOT(loadLevels(double,double)));
// if the user selected a new position on stream to play
// we have to tell it to the player
connect(ui->control, SIGNAL(elapsedSelected(qint64)),
player, SLOT(setPosition(qint64)));
// changing audio volume
connect(ui->control, SIGNAL(volumeSelected(int)),
player, SLOT(setVolume(int)));
// calculator is the thead that calcs the ffts we need to display
// every time a new spectrum is available, the calculator
// emits a calculatedSpectrum signal
connect(calculator, SIGNAL(calculatedSpectrum(QVector<double>)),
this, SLOT(spectrumAvailable(QVector<double>)));
connect(ui->library,SIGNAL(addMediaToPlayList(QString)),
SLOT(onAddMediaToPlayList(QString)));
// tells the probe what to probe
probe->setSource(player);
// load directories to library
connect(ui->actionLoadDirectory,SIGNAL(triggered()),this,SLOT(onAddFolderToLibrary()));
// load a single file to library
connect(ui->actionLoadFile,SIGNAL(triggered()),this,SLOT(loadMedia()));
// it connects the signals emiteds via the visualizer to the buttons (ui->control) and the lightCycle(ui->widgetInfo)
connect(ui->visualizer,SIGNAL(trocaCor(QColor)),ui->control,SLOT(onColorChanged(QColor)));
connect(ui->visualizer,SIGNAL(trocaCor(QColor)),ui->widgetInfo,SLOT(changedColor(QColor)));
//this->setStyleSheet(QString("QMainWindow {background-color: black}"));
}