Makes an unsuccessful attempt at producing audio.

On the plus side, it does seem successfully to sniff out an appropriate audio format and to communicate mono/stereo onward.

OSBindings/Qt/ClockSignal.pro

@@ -1,4 +1,4 @@
-QT       += core gui
+QT       += core gui multimedia
 
 greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
 

OSBindings/Qt/mainwindow.cpp

@@ -142,9 +142,17 @@ void MainWindow::launchMachine() {
 
 	switch(error) {
 		default: {
+			// TODO: correct assumptions herein that this is the first machine to be
+			// assigned to this window.
 			ui->missingROMsBox->setVisible(false);
 			uiPhase = UIPhase::RunningMachine;
 
+			// Install user-friendly options. TODO: plus user overrides.
+//			const auto configurable = machine->configurable_device();
+//			if(configurable) {
+//				configurable->set_options(configurable->get_options());
+//			}
+
 			// Supply the scan target.
 			// TODO: in the future, hypothetically, deal with non-scan producers.
 			const auto scan_producer = machine->scan_producer();
@@ -152,6 +160,33 @@ void MainWindow::launchMachine() {
 				scan_producer->set_scan_target(ui->openGLWidget->getScanTarget());
 			}
 
+			// Install audio output if required.
+			const auto audio_producer = machine->audio_producer();
+			if(audio_producer) {
+				const auto speaker = audio_producer->get_speaker();
+				if(speaker) {
+					const QAudioDeviceInfo &defaultDeviceInfo = QAudioDeviceInfo::defaultOutputDevice();
+					QAudioFormat idealFormat = defaultDeviceInfo.preferredFormat();
+
+					// Use the ideal format's sample rate, provide stereo as long as at least two channels
+					// are available, and — at least for now — assume 512 samples/buffer is a good size.
+					audioIsStereo = (idealFormat.channelCount() > 1) && speaker->get_is_stereo();
+					audioIs8bit = idealFormat.sampleSize() < 16;
+					const int samplesPerBuffer = 512;
+					speaker->set_output_rate(idealFormat.sampleRate(), samplesPerBuffer, audioIsStereo);
+
+					// Adjust format appropriately, and create an audio output.
+					idealFormat.setChannelCount(1 + int(audioIsStereo));
+					idealFormat.setSampleSize(audioIs8bit ? 8 : 16);
+					audioOutput = std::make_unique<QAudioOutput>(idealFormat, this);
+					audioOutput->setBufferSize(samplesPerBuffer * (audioIsStereo ? 2 : 1) * (audioIs8bit ? 1 : 2));
+
+					// Start the output.
+					speaker->set_delegate(this);
+					audioIODevice = audioOutput->start();
+				}
+			}
+
 			// If this is a timed machine, start up the timer.
 			const auto timedMachine = machine->timed_machine();
 			if(timedMachine) {
@@ -189,6 +224,12 @@ void MainWindow::launchMachine() {
 	}
 }
 
+void MainWindow::speaker_did_complete_samples(Outputs::Speaker::Speaker *, const std::vector<int16_t> &buffer) {
+	const auto bytesWritten = audioIODevice->write(reinterpret_cast<const char *>(buffer.data()), qint64(buffer.size()));
+//	qDebug() << bytesWritten << "; " << audioOutput->state();
+	(void)bytesWritten;
+}
+
 void MainWindow::dragEnterEvent(QDragEnterEvent* event) {
 	// Always accept dragged files.
 	if(event->mimeData()->hasUrls())

OSBindings/Qt/mainwindow.h

@@ -1,7 +1,9 @@
 #ifndef MAINWINDOW_H
 #define MAINWINDOW_H
 
+#include <QAudioOutput>
 #include <QMainWindow>
+
 #include <memory>
 #include "timer.h"
 #include "ui_mainwindow.h"
@@ -13,7 +15,7 @@ QT_BEGIN_NAMESPACE
 namespace Ui { class MainWindow; }
 QT_END_NAMESPACE
 
-class MainWindow : public QMainWindow {
+class MainWindow : public QMainWindow, public Outputs::Speaker::Speaker::Delegate {
 		Q_OBJECT
 
 		void createActions();
@@ -49,6 +51,11 @@ class MainWindow : public QMainWindow {
 		std::unique_ptr<Machine::DynamicMachine> machine;
 		std::mutex machineMutex;
 
+		std::unique_ptr<QAudioOutput> audioOutput;
+		QIODevice *audioIODevice = nullptr;
+		bool audioIs8bit = false, audioIsStereo = false;
+		void speaker_did_complete_samples(Outputs::Speaker::Speaker *speaker, const std::vector<int16_t> &buffer) override;
+
 		bool processEvent(QKeyEvent *);
 
 	private slots: