MIDI file playback using Sonivox library

Author: pedrolcl

cmdlnsynth/main.cpp

@@ -41,9 +41,16 @@ int main(int argc, char *argv[])
     signal(SIGINT, signalHandler);
     signal(SIGTERM, signalHandler);
     synth = new SynthController();
-    QObject::connect(synth, &SynthController::finished, &app, &QCoreApplication::quit);
+    QObject::connect(synth->renderer(), &SynthRenderer::playbackStopped, &app, &QCoreApplication::quit);
     QObject::connect(&app, &QCoreApplication::aboutToQuit, synth, &QObject::deleteLater);
     synth->renderer()->initReverb(EAS_PARAM_REVERB_HALL);
+    QStringList args = app.arguments();
+    for(int i = 1; i < args.length();  ++i) {
+        QFile argFile(args[i]);
+        if (argFile.exists()) {
+            synth->renderer()->playFile(argFile.fileName());
+        }
+    }
     synth->start();
     return app.exec();
 }

guisynth/guisynth.qrc

@@ -1,5 +1,8 @@
 <RCC>
     <qresource prefix="/">
         <file>icon.png</file>
+        <file>open.png</file>
+        <file>play.png</file>
+        <file>stop.png</file>
     </qresource>
 </RCC>

guisynth/mainwindow.cpp

@@ -18,13 +18,15 @@
 */
 
 #include <QCloseEvent>
+#include <QFileDialog>
 #include "mainwindow.h"
 #include "ui_mainwindow.h"
 
 MainWindow::MainWindow(QWidget *parent) :
     QMainWindow(parent),
     ui(new Ui::MainWindow),
-    m_synth(new SynthController(this))
+    m_synth(new SynthController(this)),
+    m_state(InitialState)
 {
     ui->setupUi(this);
     ui->combo_Reverb->addItem(QStringLiteral("Large Hall"), 0);
@@ -45,9 +47,16 @@ MainWindow::MainWindow(QWidget *parent) :
     connect(ui->combo_Chorus, SIGNAL(currentIndexChanged(int)), SLOT(chorusTypeChanged(int)));
     connect(ui->dial_Reverb, &QDial::valueChanged, this, &MainWindow::reverbChanged);
     connect(ui->dial_Chorus, &QDial::valueChanged, this, &MainWindow::chorusChanged);
+    connect(ui->openButton, &QToolButton::clicked, this, &MainWindow::openFile);
+    connect(ui->playButton, &QToolButton::clicked, this, &MainWindow::playSong);
+    connect(ui->stopButton, &QToolButton::clicked, this, &MainWindow::stopSong);
+    connect(m_synth->renderer(), &SynthRenderer::playbackStopped, this, &MainWindow::songStopped);
 
     ui->combo_Reverb->setCurrentIndex(1);
     ui->dial_Reverb->setValue(25800);
+
+    m_songFile = QString();
+    updateState(EmptyState);
 }
 
 MainWindow::~MainWindow()
@@ -100,3 +109,74 @@ MainWindow::chorusChanged(int value)
 {
     m_synth->renderer()->setChorusLevel(value);
 }
+
+void
+MainWindow::openFile()
+{
+    m_songFile = QFileDialog::getOpenFileName(this,
+        tr("Open MIDI file"),  QDir::homePath(),
+        tr("MIDI Files (*.mid *.midi *.kar)"));
+    if (m_songFile.isEmpty()) {
+        ui->lblSong->setText("[empty]");
+        updateState(EmptyState);
+    } else {
+        QFileInfo f(m_songFile);
+        ui->lblSong->setText(f.fileName());
+        updateState(StoppedState);
+    }
+}
+
+void
+MainWindow::playSong()
+{
+    if (m_state == StoppedState) {
+        m_synth->renderer()->startPlayback(m_songFile);
+        updateState(PlayingState);
+    }
+}
+
+void
+MainWindow::stopSong()
+{
+    if (m_state == PlayingState) {
+        m_synth->renderer()->stopPlayback();
+        updateState(StoppedState);
+    }
+}
+
+void
+MainWindow::songStopped()
+{
+    if (m_state != StoppedState) {
+        updateState(StoppedState);
+    }
+}
+
+void
+MainWindow::updateState(PlayerState newState)
+{
+    //qDebug() << Q_FUNC_INFO << newState;
+    if (m_state != newState) {
+        switch (newState) {
+        case EmptyState:
+            ui->playButton->setEnabled(false);
+            ui->stopButton->setEnabled(false);
+            ui->openButton->setEnabled(true);
+            break;
+        case PlayingState:
+            ui->playButton->setEnabled(false);
+            ui->stopButton->setEnabled(true);
+            ui->openButton->setEnabled(false);
+            break;
+        case StoppedState:
+            ui->stopButton->setEnabled(true);
+            ui->playButton->setEnabled(true);
+            ui->playButton->setChecked(false);
+            ui->openButton->setEnabled(true);
+            break;
+        default:
+            break;
+        }
+        m_state = newState;
+    }
+}

guisynth/mainwindow.h

@@ -23,6 +23,13 @@
 #include <QMainWindow>
 #include "synthcontroller.h"
 
+enum PlayerState {
+    InitialState,
+    EmptyState,
+    PlayingState,
+    StoppedState
+};
+
 namespace Ui {
 class MainWindow;
 }
@@ -34,6 +41,7 @@ class MainWindow : public QMainWindow
 public:
     explicit MainWindow(QWidget *parent = 0);
     ~MainWindow();
+    void updateState(PlayerState newState);
 
 protected:
     virtual void showEvent(QShowEvent *ev);
@@ -44,10 +52,17 @@ private slots:
     void chorusTypeChanged(int index);
     void reverbChanged(int value);
     void chorusChanged(int value);
+    void songStopped();
+
+    void openFile();
+    void playSong();
+    void stopSong();
 
 private:
     Ui::MainWindow *ui;
     SynthController *m_synth;
+    QString m_songFile;
+    PlayerState m_state;
 };
 
 #endif // MAINWINDOW_H

guisynth/mainwindow.ui

@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>250</width>
-    <height>167</height>
+    <width>190</width>
+    <height>208</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -19,7 +19,73 @@
   </property>
   <widget class="QWidget" name="centralWidget">
    <layout class="QGridLayout" name="gridLayout">
-    <item row="0" column="0">
+    <item row="0" column="0" colspan="3">
+     <layout class="QHBoxLayout" name="horizontalLayout">
+      <item>
+       <widget class="QToolButton" name="playButton">
+        <property name="text">
+         <string>...</string>
+        </property>
+        <property name="icon">
+         <iconset resource="guisynth.qrc">
+          <normaloff>:/play.png</normaloff>:/play.png</iconset>
+        </property>
+        <property name="checkable">
+         <bool>true</bool>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="QToolButton" name="stopButton">
+        <property name="text">
+         <string>...</string>
+        </property>
+        <property name="icon">
+         <iconset resource="guisynth.qrc">
+          <normaloff>:/stop.png</normaloff>:/stop.png</iconset>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="QToolButton" name="openButton">
+        <property name="text">
+         <string>...</string>
+        </property>
+        <property name="icon">
+         <iconset resource="guisynth.qrc">
+          <normaloff>:/open.png</normaloff>:/open.png</iconset>
+        </property>
+        <property name="checkable">
+         <bool>false</bool>
+        </property>
+        <property name="checked">
+         <bool>false</bool>
+        </property>
+       </widget>
+      </item>
+      <item>
+       <widget class="QLabel" name="lblSong">
+        <property name="text">
+         <string>[empty]</string>
+        </property>
+       </widget>
+      </item>
+     </layout>
+    </item>
+    <item row="1" column="1" colspan="2">
+     <spacer name="verticalSpacer">
+      <property name="orientation">
+       <enum>Qt::Vertical</enum>
+      </property>
+      <property name="sizeHint" stdset="0">
+       <size>
+        <width>20</width>
+        <height>8</height>
+       </size>
+      </property>
+     </spacer>
+    </item>
+    <item row="2" column="0">
      <widget class="QLabel" name="lblReverb">
       <property name="text">
        <string>Reverb</string>
@@ -29,7 +95,7 @@
       </property>
      </widget>
     </item>
-    <item row="0" column="1">
+    <item row="2" column="2">
      <widget class="QLabel" name="lblChorus">
       <property name="text">
        <string>Chorus</string>
@@ -39,24 +105,24 @@
       </property>
      </widget>
     </item>
-    <item row="1" column="0">
+    <item row="3" column="0" colspan="2">
      <widget class="QDial" name="dial_Reverb">
       <property name="maximum">
        <number>32765</number>
       </property>
      </widget>
     </item>
-    <item row="1" column="1">
+    <item row="3" column="2">
      <widget class="QDial" name="dial_Chorus">
       <property name="maximum">
        <number>32765</number>
       </property>
      </widget>
     </item>
-    <item row="2" column="0">
+    <item row="4" column="0" colspan="2">
      <widget class="QComboBox" name="combo_Reverb"/>
     </item>
-    <item row="2" column="1">
+    <item row="4" column="2">
      <widget class="QComboBox" name="combo_Chorus"/>
     </item>
    </layout>

guisynth/open.png

@@ -9,12 +9,14 @@ link_directories(
 set( HEADERS
     synthcontroller.h
     synthrenderer.h
-)    
+    filewrapper.h
+)
 
 set( SOURCES
     synthcontroller.cpp 
     synthrenderer.cpp
-)    
+    filewrapper.cpp
+)
 
 qt5_wrap_cpp( MOC_SRCS ${HEADERS} )
 

guisynth/play.png

@@ -0,0 +1,78 @@
+/*
+    Sonivox EAS Synthesizer for Qt applications
+    Copyright (C) 2016, Pedro Lopez-Cabanillas <plcl@users.sf.net>
+
+    This library is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+
+#include <QDebug>
+#include "filewrapper.h"
+
+static int
+readAt(void *handle, void *buffer, int pos, int size) {
+    return ((FileWrapper*)handle)->readAt(buffer, pos, size);
+}
+
+static int
+size(void *handle) {
+    return ((FileWrapper*)handle)->size();
+}
+
+FileWrapper::FileWrapper(const QString path)
+{
+    //qDebug() << Q_FUNC_INFO << path;
+    m_file = new QFile(path);
+    m_file->open(QIODevice::ReadOnly);
+    m_Base = 0;
+    m_Length = m_file->size();
+}
+
+FileWrapper::FileWrapper(const char *path)
+{
+    //qDebug("FileWrapper(path=%s)", path);
+    m_file = new QFile(path);
+    m_file->open(QIODevice::ReadOnly);
+    m_Base = 0;
+    m_Length = m_file->size();
+}
+
+FileWrapper::~FileWrapper() {
+    //qDebug("~FileWrapper");
+    m_file->close();
+}
+
+int
+FileWrapper::readAt(void *buffer, int offset, int size) {
+    //qDebug("readAt(%p, %d, %d)", buffer, offset, size);
+    m_file->seek(offset);
+    if (offset + size > m_Length) {
+        size = m_Length - offset;
+    }
+    return m_file->read((char *)buffer, size);
+}
+
+int
+FileWrapper::size() {
+    //qDebug("size() = %d", int(mLength));
+    return m_Length;
+}
+
+EAS_FILE_LOCATOR
+FileWrapper::getLocator() {
+    m_easFile.handle = this;
+    m_easFile.readAt = ::readAt;
+    m_easFile.size = ::size;
+    return &m_easFile;
+}