Add ability to change sample rate in the settings menu (#7719)

Add a slider in the audio settings menu to allow users to select a few standard sample rates, those being 44100, 48000, 88200, 96000, and 192000.

include/AudioEngine.h

@@ -50,7 +50,6 @@ class MidiClient;
 class AudioBusHandle;
 class AudioEngineWorkerThread;
 
-
 constexpr fpp_t MINIMUM_BUFFER_SIZE = 32;
 constexpr fpp_t DEFAULT_BUFFER_SIZE = 256;
 constexpr fpp_t MAXIMUM_BUFFER_SIZE = 4096;
@@ -61,6 +60,8 @@ constexpr int BYTES_PER_FRAME = sizeof(SampleFrame);
 
 constexpr float OUTPUT_SAMPLE_MULTIPLIER = 32767.0f;
 
+constexpr auto SUPPORTED_SAMPLERATES = std::array{44100, 48000, 88200, 96000, 192000}; 
+
 class LMMS_EXPORT AudioEngine : public QObject
 {
 	Q_OBJECT

include/SetupDialog.h

@@ -182,6 +182,8 @@ private:
 	QSlider * m_bufferSizeSlider;
 	QLabel * m_bufferSizeLbl;
 	QLabel * m_bufferSizeWarnLbl;
+	int m_sampleRate;
+	QSlider* m_sampleRateSlider;
 
 	// MIDI settings widgets.
 	QComboBox * m_midiInterfaces;

src/core/AudioEngine.cpp

@@ -73,7 +73,7 @@ static thread_local bool s_renderingThread = false;
 AudioEngine::AudioEngine( bool renderOnly ) :
 	m_renderOnly( renderOnly ),
 	m_framesPerPeriod( DEFAULT_BUFFER_SIZE ),
-	m_baseSampleRate(std::max(ConfigManager::inst()->value("audioengine", "samplerate").toInt(), 44100)),
+	m_baseSampleRate(std::max(ConfigManager::inst()->value("audioengine", "samplerate").toInt(), SUPPORTED_SAMPLERATES.front())),
 	m_inputBufferRead( 0 ),
 	m_inputBufferWrite( 1 ),
 	m_outputBufferRead(nullptr),

src/gui/modals/ExportProjectDialog.cpp

@@ -98,6 +98,14 @@ ExportProjectDialog::ExportProjectDialog( const QString & _file_name,
 	compressionWidget->setVisible(false);
 #endif
 
+	for (const auto sampleRate : SUPPORTED_SAMPLERATES)
+	{
+		samplerateCB->addItem(tr("%1 Hz").arg(sampleRate), sampleRate);
+	}
+
+	const auto currentIndex = std::max(0, samplerateCB->findData(Engine::audioEngine()->outputSampleRate()));
+	samplerateCB->setCurrentIndex(currentIndex);
+
 	connect( startButton, SIGNAL(clicked()),
 			this, SLOT(startBtnClicked()));
 }
@@ -156,12 +164,9 @@ void ExportProjectDialog::startExport()
 {
 	auto qs = AudioEngine::qualitySettings(
 		static_cast<AudioEngine::qualitySettings::Interpolation>(interpolationCB->currentIndex()));
-	const auto samplerates = std::array{44100, 48000, 88200, 96000, 192000};
 	const auto bitrates = std::array{64, 128, 160, 192, 256, 320};
 
-	const auto bitrate = bitrates[bitrateCB->currentIndex()];
-
-	OutputSettings os = OutputSettings(samplerates[samplerateCB->currentIndex()], bitrate,
+	OutputSettings os = OutputSettings(samplerateCB->currentData().toInt(), bitrates[bitrateCB->currentIndex()],
 		static_cast<OutputSettings::BitDepth>(depthCB->currentIndex()),
 		mapToStereoMode(stereoModeComboBox->currentIndex()));
 

src/gui/modals/SetupDialog.cpp

@@ -143,6 +143,8 @@ SetupDialog::SetupDialog(ConfigTab tab_to_open) :
 			"app", "nanhandler", "1").toInt()),
 	m_bufferSize(ConfigManager::inst()->value(
 			"audioengine", "framesperaudiobuffer").toInt()),
+	m_sampleRate(ConfigManager::inst()->value(
+			"audioengine", "samplerate").toInt()),
 	m_midiAutoQuantize(ConfigManager::inst()->value(
 			"midi", "autoquantize", "0").toInt() != 0),
 	m_workingDir(QDir::toNativeSeparators(ConfigManager::inst()->workingDir())),
@@ -557,6 +559,44 @@ SetupDialog::SetupDialog(ConfigTab tab_to_open) :
 	// audio_layout->addWidget(useNaNHandler);
 	// useNaNHandler->setChecked(m_NaNHandler);
 
+	auto sampleRateBox = new QGroupBox{tr("Sample rate"), audio_w};
+
+	m_sampleRateSlider = new QSlider{Qt::Horizontal};
+	m_sampleRateSlider->setRange(0, SUPPORTED_SAMPLERATES.size() - 1);
+	m_sampleRateSlider->setTickPosition(QSlider::TicksBelow);
+
+	auto sampleRateResetButton = new QPushButton{embed::getIconPixmap("reload"), ""};
+	sampleRateResetButton->setFixedSize(32, 32);
+
+	auto sampleRateSubLayout = new QHBoxLayout{};
+	sampleRateSubLayout->addWidget(m_sampleRateSlider);
+	sampleRateSubLayout->addWidget(sampleRateResetButton);
+
+	auto sampleRateLabel = new QLabel{sampleRateBox};
+	auto sampleRateLayout = new QVBoxLayout{sampleRateBox};
+	sampleRateLayout->addLayout(sampleRateSubLayout);
+	sampleRateLayout->addWidget(sampleRateLabel);
+
+	auto setSampleRate = [this, sampleRateLabel](int sampleRate)
+	{	
+		const auto it = std::find(SUPPORTED_SAMPLERATES.begin(), SUPPORTED_SAMPLERATES.end(), sampleRate);
+		const auto index = it == SUPPORTED_SAMPLERATES.end() ? 0 : std::distance(SUPPORTED_SAMPLERATES.begin(), it);
+
+		m_sampleRate = SUPPORTED_SAMPLERATES[index];
+		m_sampleRateSlider->setValue(index);
+		sampleRateLabel->setText(tr("Sample rate: %1").arg(m_sampleRate));
+	};
+
+	setSampleRate(m_sampleRate);
+
+	connect(m_sampleRateSlider, &QSlider::valueChanged, this, &SetupDialog::showRestartWarning);
+
+	connect(m_sampleRateSlider, &QSlider::valueChanged, this,
+		[setSampleRate](int value) { setSampleRate(SUPPORTED_SAMPLERATES[value]); });
+
+	connect(sampleRateResetButton, &QPushButton::clicked, this,
+		[setSampleRate] { setSampleRate(SUPPORTED_SAMPLERATES.front()); });
+
 	// Buffer size group
 	QGroupBox * bufferSizeBox = new QGroupBox(tr("Buffer size"), audio_w);
 	QVBoxLayout * bufferSizeLayout = new QVBoxLayout(bufferSizeBox);
@@ -598,6 +638,7 @@ SetupDialog::SetupDialog(ConfigTab tab_to_open) :
 	// Audio layout ordering.
 	audio_layout->addWidget(audioInterfaceBox);
 	audio_layout->addWidget(as_w);
+	audio_layout->addWidget(sampleRateBox);
 	audio_layout->addWidget(bufferSizeBox);
 	audio_layout->addStretch();
 
@@ -962,6 +1003,8 @@ void SetupDialog::accept()
 					m_audioIfaceNames[m_audioInterfaces->currentText()]);
 	ConfigManager::inst()->setValue("app", "nanhandler",
 					QString::number(m_NaNHandler));
+	ConfigManager::inst()->setValue("audioengine", "samplerate",
+					QString::number(m_sampleRate));
 	ConfigManager::inst()->setValue("audioengine", "framesperaudiobuffer",
 					QString::number(m_bufferSize));
 	ConfigManager::inst()->setValue("audioengine", "mididev",

src/gui/modals/export_project.ui

@@ -122,33 +122,7 @@
             </widget>
            </item>
            <item>
-            <widget class="QComboBox" name="samplerateCB">
-             <item>
-              <property name="text">
-               <string>44100 Hz</string>
-              </property>
-             </item>
-             <item>
-              <property name="text">
-               <string>48000 Hz</string>
-              </property>
-             </item>
-             <item>
-              <property name="text">
-               <string>88200 Hz</string>
-              </property>
-             </item>
-             <item>
-              <property name="text">
-               <string>96000 Hz</string>
-              </property>
-             </item>
-             <item>
-              <property name="text">
-               <string>192000 Hz</string>
-              </property>
-             </item>
-            </widget>
+            <widget class="QComboBox" name="samplerateCB" />
            </item>
           </layout>
          </widget>