**Customizing MIDI File Player with Qt Multimedia and QML** This example demonstrates how to create a MIDI file player with custom visualization and animation using Qt Multimedia and QML. ### Overview The application plays a selected MIDI file and displays a visualization of the notes being played. The visualization uses QML's built-in animation features to create a modern and engaging design. ### Prerequisites * Qt 6.2 or later * Qt Multimedia * Qt QML * Qt Quick * Python 3.x ### Code **main.py** ```python import sys from PySide6.QtCore import QUrl from PySide6.QtGui import QGuiApplication from PySide6.QtQml import QQmlApplicationEngine from PySide6.QtMultimedia import QMidiFilePlayer class MidiPlayer(QGuiApplication): def __init__(self): super().__init__() self.engine = QQmlApplicationEngine() self.engine.load(QUrl("qrc:///main.qml")) # Create MIDI player self.player = QMidiFilePlayer(self) self.player.setFormat(QMidiFilePlayer.FORMAT_MIDI_0) # Set up MIDI file self.file = "path/to/your/midi/file.mid" self.player.setMidiFile(self.file) def start.play(self): self.player.start() if __name__ == "__main__": app = MidiPlayer(sys.argv) sys.exit(app.exec()) ``` **main.qml** ```qml import QtQuick 6.2 import QtQuick.Controls 6.2 import QtMultimedia 6.2 ApplicationWindow { width: 800 height: 600 title: "MIDI File Player" // Visualization Rectangle { anchors.fill: parent color: "black" // Note visualization Repeater { model: 100 Rectangle { width: 10 height: 10 color: "red" opacity: 0 x: index * 10 y: 0 NumberAnimation on opacity { running: true from: 0 to: 1 duration: 1000 } } } } // Play button Button { text: "Play" anchors.centerIn: parent onClicked: { // Start playing MIDI file midiPlayer.start.play() } } // Connect to C++ for MIDI file player Connections { target: midiPlayer function onNotePlayed(note) { // Update visualization visual.repeater[index].opacity = 1 } } } ``` ** midiplayer.h** ```c #ifndef MIDPLAYER_H #define MIDPLAYER_H #include <QObject> #include <QmidiFilePlayer> class MidiPlayer : public QObject { Q_OBJECT public: explicit MidiPlayer(QObject *parent = nullptr); void startPlay(); signals: void playNote(int note); private: QMidiFilePlayer player; }; #endif // MIDPLAYER_H ``` ** midiplayer.cpp** ```c #include "midiplayer.h" MidiPlayer::MidiPlayer(QObject *parent) : QObject(parent) { connect(&player, &QMidiFilePlayer::noteOn, this, [this](int note, int velocity) { emit playNote(note); }); } void MidiPlayer::startPlay() { player.start(); } ``` ** Resources.qrc** ``` <RCC> <qresource prefix="/"> <file>main.qml</file> </qresource> </RCC> ``` ### Build and Run 1. Create a new directory for your project and navigate into it. 2. Create a new file called `main.py` and copy the Python code above into it. 3. Create a new file called `main.qml` and copy the QML code above into it. 4. Create a new file called `midiplayer.h` and copy the C++ code above into it. 5. Create a new file called `midiplayer.cpp` and copy the C++ code above into it. 6. Create a new file called `Resources.qrc` and copy the resource code above into it. 7. Build the project using `qmake` and `make`. 8. Run the project using `./main`. ### Notes * This example uses Qt QML for the user interface and Qt Multimedia for playing MIDI files. * The visualization is implemented using QML's built-in animation features. * The C++ code is used to communicate with the QML code and play the MIDI file. ### Conclusion This example demonstrates how to create a MIDI file player with custom visualization and animation using Qt Multimedia and QML. The application plays a selected MIDI file and displays a visualization of the notes being played. The visualization uses QML's built-in animation features to create a modern and engaging design.