Fix some compiler warnings.

As it turns out, we had an overloaded virtual from an earlier era,
with the extra parameter never used.  So cleaning that up was a
bonus to remove the compiler warning.

Change-Id: I780287f8a5d2b0a1ec84ec62c88ba50e051f372b
Reviewed-by: Jonas Rabbe <jonas.rabbe@nokia.com>

examples/audiodevices/audiodevices.cpp

@@ -58,6 +58,8 @@ QString toString(QAudioFormat::SampleType sampleType)
     case QAudioFormat::Float:
         result = "Float";
         break;
+    case QAudioFormat::Unknown:
+        result = "Unknown";
     }
     return result;
 }

examples/spectrum/app/waveform.cpp

@@ -393,6 +393,7 @@ void Waveform::paintTile(int index)
         const int offset = reinterpret_cast<const char*>(ptr) - m_buffer.constData();
         Q_ASSERT(offset >= 0);
         Q_ASSERT(offset < m_bufferLength);
+        Q_UNUSED(offset);
 
         const qint16 pcmValue = *ptr;
         const qreal realValue = pcmToReal(pcmValue);

examples/spectrum/app/wavfile.h

@@ -51,6 +51,7 @@ class WavFile : public QFile
 public:
     WavFile(QObject *parent = 0);
 
+    using QFile::open;
     bool open(const QString &fileName);
     const QAudioFormat &fileFormat() const;
     qint64 headerLength() const;

examples/videowidget/videowidgetsurface.cpp

@@ -69,11 +69,8 @@ QList<QVideoFrame::PixelFormat> VideoWidgetSurface::supportedPixelFormats(
 //! [0]
 
 //! [1]
-bool VideoWidgetSurface::isFormatSupported(
-        const QVideoSurfaceFormat &format, QVideoSurfaceFormat *similar) const
+bool VideoWidgetSurface::isFormatSupported(const QVideoSurfaceFormat &format) const
 {
-    Q_UNUSED(similar);
-
     const QImage::Format imageFormat = QVideoFrame::imageFormatFromPixelFormat(format.pixelFormat());
     const QSize size = format.frameSize();
 

examples/videowidget/videowidgetsurface.h

@@ -55,7 +55,7 @@ public:
 
     QList<QVideoFrame::PixelFormat> supportedPixelFormats(
             QAbstractVideoBuffer::HandleType handleType = QAbstractVideoBuffer::NoHandle) const;
-    bool isFormatSupported(const QVideoSurfaceFormat &format, QVideoSurfaceFormat *similar) const;
+    bool isFormatSupported(const QVideoSurfaceFormat &format) const;
 
     bool start(const QVideoSurfaceFormat &format);
     void stop();