Finished implementing waveform plotting.

Speqtrogram.pro

@@ -17,13 +17,15 @@ SOURCES += main.cpp\
         mainwindow.cpp \
     devicelist.cpp \
     hostapilist.cpp \
-    paplayback.cpp
+    paplayback.cpp \
+    waveformwidget.cpp
 
 HEADERS  += mainwindow.h\
         portaudio.h \
     devicelist.h \
     hostapilist.h \
-    paplayback.h
+    paplayback.h \
+    waveformwidget.h
 
 FORMS    += mainwindow.ui
 

mainwindow.cpp

@@ -13,6 +13,7 @@ MainWindow::MainWindow(QWidget *parent) :
     ui(new Ui::MainWindow)
 {
     ui->setupUi(this);
+    ui->waveformView->setMinimumHeight(20);
     ui->hostApiList->setModel(new HostApiList());
     ui->deviceList->setModel(new DeviceList());
 
@@ -63,38 +64,7 @@ void MainWindow::open()
                                                     tr("Sound Files (*.wav *.flac *.aiff *.ogg)"));
     QDir::setCurrent(QFileInfo(fileName).absolutePath());
     player.openSoundFile(fileName.toStdString());
-
-    QGraphicsScene *waveformNavigatorScene = new QGraphicsScene();
-    QPainterPath waveformMax(QPointF(0,0));
-    QPainterPath waveformMin(QPointF(0,0));
-    SndfileHandle soundFile(fileName.toStdString());
-    if (soundFile.error()) {
-        qDebug() << soundFile.strError();
-    }
-    sf_count_t framesPerPixel = soundFile.frames()/ui->waveformNavigator->width();
-    float samples[framesPerPixel*soundFile.channels()];
-    sf_count_t totalFrames = 0;
-    while (soundFile.readf(samples, framesPerPixel) != 0) {
-        float maximum = 0;
-        float minimum = 0;
-        for (int f=0; f<framesPerPixel; f++) {
-            for (int c=0; c<soundFile.channels(); c++) {
-                maximum = samples[f*c+c] > maximum ? samples[f*c+c] : maximum;
-                minimum = samples[f*c+c] < minimum ? samples[f*c+c] : minimum;
-            }
-        }
-        waveformMax.lineTo(totalFrames/framesPerPixel, maximum*ui->waveformNavigator->height()*0.5);
-        waveformMin.lineTo(totalFrames/framesPerPixel, minimum*ui->waveformNavigator->height()*0.5);
-        totalFrames += framesPerPixel;
-    }
-    QColor lightBlue = QColor(Qt::blue);
-    lightBlue.setAlphaF(0.5);
-    waveformNavigatorScene->addPath(waveformMax, QPen(Qt::blue), QBrush(lightBlue));
-    waveformNavigatorScene->addPath(waveformMin, QPen(Qt::blue), QBrush(lightBlue));
-    ui->waveformNavigator->setScene(waveformNavigatorScene);
-    ui->waveformNavigator->setRenderHint(QPainter::Antialiasing, true);
-
-    qDebug() << ui->waveformNavigator->sceneRect();
+    ui->waveformView->setSoundFile(fileName);
 }
 
 void MainWindow::changePlayButtonState(bool isPlaying)

mainwindow.ui

@@ -39,7 +39,7 @@
      </layout>
     </item>
     <item>
-     <widget class="QGraphicsView" name="waveformNavigator"/>
+     <widget class="WaveformWidget" name="waveformView" native="true"/>
     </item>
     <item>
      <widget class="QWidget" name="spectrogram" native="true"/>
@@ -135,6 +135,14 @@
   <widget class="QStatusBar" name="statusBar"/>
  </widget>
  <layoutdefault spacing="6" margin="11"/>
+ <customwidgets>
+  <customwidget>
+   <class>WaveformWidget</class>
+   <extends>QWidget</extends>
+   <header>waveformwidget.h</header>
+   <container>1</container>
+  </customwidget>
+ </customwidgets>
  <resources/>
  <connections/>
 </ui>

waveformwidget.cpp

@@ -0,0 +1,60 @@
+#include "waveformwidget.h"
+#include <QPainter>
+#include <QApplication>
+#include <QDesktopWidget>
+#include "sndfile.hh"
+#include <QDebug>
+
+WaveformWidget::WaveformWidget(QWidget *parent) :
+    QWidget(parent)
+{
+}
+
+void WaveformWidget::setSoundFile(QString filename)
+{
+    QPainterPath waveformMax(QPointF(0,0));
+    QPainterPath waveformMin(QPointF(0,0));
+    SndfileHandle soundFile(filename.toStdString());
+    if (soundFile.error()) qDebug() << soundFile.strError();
+
+    QDesktopWidget *desk = QApplication::desktop();
+    int totalPixelCount = (desk->screenGeometry().width()*desk->screenCount());
+    sf_count_t framesPerPixel = soundFile.frames()/totalPixelCount;
+    Q_ASSERT(framesPerPixel >= 1);
+    float samples[framesPerPixel*soundFile.channels()];
+    sf_count_t totalFrames = 0;
+    while (soundFile.readf(samples, framesPerPixel) != 0) {
+        float maximum = 0;
+        float minimum = 0;
+        for (int f=0; f<framesPerPixel; f++) {
+            for (int c=0; c<soundFile.channels(); c++) {
+                maximum = samples[f*c+c] > maximum ? samples[f*c+c] : maximum;
+                minimum = samples[f*c+c] < minimum ? samples[f*c+c] : minimum;
+            }
+        }
+        waveformMax.lineTo(double(totalFrames)/(framesPerPixel*totalPixelCount), maximum);
+        waveformMin.lineTo(double(totalFrames)/(framesPerPixel*totalPixelCount), minimum);
+        totalFrames += framesPerPixel;
+    }
+    maxWave.swap(waveformMax);
+    minWave.swap(waveformMin);
+}
+
+void WaveformWidget::paintEvent(QPaintEvent *event)
+{
+    (void)event;
+    QPainter painter(this);
+    painter.setBrush(Qt::white);
+    painter.drawRect(QRect(QPoint(),this->size()));
+
+    QColor lightBlue = QColor(Qt::blue);
+    lightBlue.setAlphaF(0.5);
+    painter.setBrush(QBrush(lightBlue));
+    painter.setPen(QPen(QBrush(Qt::blue), 0));
+
+    painter.scale(width(), height()/2);
+    painter.translate(0,1);
+    painter.setRenderHint(QPainter::Antialiasing, true);
+    painter.drawPath(maxWave);
+    painter.drawPath(minWave);
+}

waveformwidget.h

@@ -0,0 +1,23 @@
+#ifndef WAVEFORMWIDGET_H
+#define WAVEFORMWIDGET_H
+
+#include <QWidget>
+#include <QUrl>
+
+class WaveformWidget : public QWidget
+{
+    Q_OBJECT
+public:
+    explicit WaveformWidget(QWidget *parent = 0);
+    void paintEvent(QPaintEvent* event);
+    void setSoundFile(QString filename);
+signals:
+
+public slots:
+
+private:
+    QPainterPath maxWave;
+    QPainterPath minWave;
+};
+
+#endif // WAVEFORMWIDGET_H