Qt5 upgrade and new audio engine based in QtMultimedia.

New GUI.

src/audiodecoder.h

@@ -0,0 +1,45 @@
+#ifndef AUDIODECODER_H
+#define AUDIODECODER_H
+
+#include <QIODevice>
+#include <QAudioFormat>
+#include <QAudioDecoder>
+
+class AudioDecoder : public QIODevice
+{
+    Q_OBJECT
+
+public:
+    AudioDecoder(const QAudioFormat &format, qint64 durationUs, int sampleRate, QObject *parent);
+    AudioDecoder(const QAudioFormat &format, QObject *parent);
+    ~AudioDecoder();
+
+    void start();
+    void stop();
+
+    qint64 readData(char *data, qint64 maxlen);
+    qint64 writeData(const char *data, qint64 len);
+    qint64 bytesAvailable() const;
+
+    void loadMedia(QString file);
+
+    void setPos(qint64 pos);
+
+private:
+    void generateData(const QAudioFormat &format, qint64 durationUs, int sampleRate);
+    qint64 m_pos;
+    QByteArray m_buffer;
+    QAudioDecoder *m_decoder;
+
+private slots:
+    void readBuffer();
+    void errorDecoding(QAudioDecoder::Error msg);
+    void decoderFinished();
+    void trackTimeChanged(qint64 dur);
+
+signals:
+    void totalTimeChanged(qint64 dur);
+    void fileLoaded(QString file);
+};
+
+#endif // AUDIODECODER_H