Reset Channel Instruments on File Load

Author: Meowchestra

src/gui/MainWindow.cpp

@@ -749,6 +749,18 @@ void MainWindow::setFile(MidiFile *newFile) {
     copiedEventsChanged();
     checkEnableActionsForSelection();
 
+    // Reset MIDI output channel programs and apply initial program changes
+    if (MidiOutput::isConnected()) {
+        MidiOutput::resetChannelPrograms();
+        // Send program change events from the beginning of the file
+        for (int ch = 0; ch < 16; ch++) {
+            int prog = file->channel(ch)->progAtTick(0);
+            if (prog >= 0) {
+                MidiOutput::sendProgram(ch, prog);
+            }
+        }
+    }
+
     // Clean up the old file after everything has been switched to the new file
     // This ensures all widgets have switched to the new file before cleanup
     if (oldFile) {

src/midi/MidiOutput.cpp

@@ -149,6 +149,14 @@ void MidiOutput::sendProgram(int channel, int prog) {
     sendCommand(array);
 }
 
+void MidiOutput::resetChannelPrograms()
+{
+    // Reset all 16 MIDI channels to program 0 (Acoustic Grand Piano in GM)
+    for (int channel = 0; channel < 16; channel++) {
+        sendProgram(channel, 0);
+    }
+}
+
 bool MidiOutput::isConnected() {
     return _outPort != "";
 }

src/midi/MidiOutput.h

@@ -131,6 +131,11 @@ class MidiOutput : public QObject {
      */
     static void sendProgram(int channel, int prog);
 
+    /**
+     * \brief Resets the MIDI channel program instruments.
+     */
+    static void resetChannelPrograms();
+
     // === Public State Variables ===
 
     /** \brief Flag indicating if using alternative player */