PulseAudio: Cork audio input when it isn't needed

src/mumble/AudioWizard.cpp

@@ -36,6 +36,7 @@ AudioWizard::AudioWizard(QWidget *p) : QWizard(p) {
 	bInit = true;
 	bLastActive = false;
 	g.bInAudioWizard = true;
+	g.mw->onChangeMute();
 
 	ticker = new QTimer(this);
 	ticker->setObjectName(QLatin1String("Ticker"));
@@ -398,6 +399,7 @@ void AudioWizard::reject() {
 		ao->wipe();
 	aosSource = NULL;
 	g.bInAudioWizard = false;
+	g.mw->onChangeMute();
 
 	QWizard::reject();
 }
@@ -433,6 +435,7 @@ void AudioWizard::accept() {
 	g.bPosTest = false;
 	restartAudio();
 	g.bInAudioWizard = false;
+	g.mw->onChangeMute();
 	QWizard::accept();
 }
 

src/mumble/MainWindow.cpp

@@ -2306,6 +2306,7 @@ void MainWindow::on_qaAudioMute_triggered() {
 		g.sh->setSelfMuteDeafState(g.s.bMute, g.s.bDeaf);
 	}
 
+	onChangeMute();
 	updateTrayIcon();
 }
 
@@ -2342,6 +2343,7 @@ void MainWindow::on_qaAudioDeaf_triggered() {
 		g.sh->setSelfMuteDeafState(g.s.bMute, g.s.bDeaf);
 	}
 
+	onChangeMute();
 	updateTrayIcon();
 }
 
@@ -2790,6 +2792,15 @@ void MainWindow::whisperReleased(QVariant scdata) {
 	updateTarget();
 }
 
+void MainWindow::onChangeMute()
+{
+	if (!g.ai) {
+		return;
+	}
+
+	emit corkAudioInputStream(g.s.bMute && !g.bInAudioWizard);
+}
+
 void MainWindow::onResetAudio()
 {
 	qWarning("MainWindow: Start audio reset");
@@ -2849,6 +2860,7 @@ void MainWindow::serverConnected() {
 
 	if (g.s.bMute || g.s.bDeaf) {
 		g.sh->setSelfMuteDeafState(g.s.bMute, g.s.bDeaf);
+		onChangeMute();
 	}
 
 	// Update QActions and menues

src/mumble/MainWindow.h

@@ -269,6 +269,9 @@ class MainWindow : public QMainWindow, public MessageHandler, public Ui::MainWin
 		void pttReleased();
 		void whisperReleased(QVariant scdata);
 		void onResetAudio();
+		/// Called whenever the self-mute state may have changed. Dispatches
+		/// corkAudioInputStream() if the desire for audio input has changed.
+		void onChangeMute();
 		void showRaiseWindow();
 		void on_qaFilterToggle_triggered();
 		/// Opens a save dialog for the image referenced by qtcSaveImageCursor.
@@ -279,7 +282,16 @@ class MainWindow : public QMainWindow, public MessageHandler, public Ui::MainWin
 		/// Updates the user's image directory to the given path (any included
 		/// filename is discarded).
 		void updateImagePath(QString filepath) const;
-
+	signals:
+		/// Reports that audio input is now, or is no longer, required.
+		///
+		/// Signal allows an \ref AudioInput to suspend the input stream
+		/// when it is not required.
+		///
+		/// @param cork  If true, the audio backend MAY now cork/suspend
+		/// the input stream. If false, the audio backend MUST immediately
+		/// un-cork/resume the stream.
+		void corkAudioInputStream(const bool cork);
 	public:
 		MainWindow(QWidget *parent);
 		~MainWindow() Q_DECL_OVERRIDE;

src/mumble/PulseAudio.cpp

@@ -301,6 +301,11 @@ void PulseAudioSystem::eventCallback(pa_mainloop_api *api, pa_defer_event *) {
 			qsInputCache = idev;
 
 			pa_stream_connect_record(pasInput, qPrintable(idev), &buff, PA_STREAM_ADJUST_LATENCY);
+
+			// Ensure stream is initially un-muted
+			pa_stream_cork(pasInput, 0, NULL, NULL);
+
+			connect(g.mw, &MainWindow::corkAudioInputStream, this, &PulseAudioSystem::corkAudioInputStream);
 		}
 	}
 
@@ -371,6 +376,15 @@ void PulseAudioSystem::eventCallback(pa_mainloop_api *api, pa_defer_event *) {
 	}
 }
 
+void PulseAudioSystem::corkAudioInputStream(const bool cork)
+{
+	if (pasInput) {
+		pa_threaded_mainloop_lock(pam);
+		pa_stream_cork(pasInput, cork, nullptr, nullptr);
+		pa_threaded_mainloop_unlock(pam);
+	}
+}
+
 void PulseAudioSystem::context_state_callback(pa_context *c, void *userdata) {
 	PulseAudioSystem *pas = reinterpret_cast<PulseAudioSystem *>(userdata);
 	pas->contextCallback(c);

src/mumble/PulseAudio.h

@@ -80,6 +80,9 @@ class PulseAudioSystem : public QObject {
 		void setVolumes();
 		PulseAttenuation* getAttenuation(QString stream_restore_id);
 
+	public slots:
+		void corkAudioInputStream(const bool cork);
+
 	public:
 		QHash<QString, QString> qhInput;
 		QHash<QString, QString> qhOutput;

src/mumble/main.cpp

@@ -479,6 +479,7 @@ int main(int argc, char **argv) {
 	g.p->rescanPlugins();
 
 	Audio::start();
+	g.mw->onChangeMute();
 
 	a.setQuitOnLastWindowClosed(false);