Add None audio I/O devices

Can be changed in the middle of a call without problem

src/audio/audio.cpp

@@ -191,6 +191,9 @@ void Audio::openInput(const QString& inDevDescr)
     }
     alInDev = nullptr;
 
+    if (inDevDescr == "none")
+        return;
+
     /// TODO: Try to actually detect if our audio source is stereo
     int stereoFlag = AUDIO_CHANNELS == 1 ? AL_FORMAT_MONO16 : AL_FORMAT_STEREO16;
     const uint32_t sampleRate = AUDIO_SAMPLE_RATE;
@@ -235,35 +238,43 @@ bool Audio::openOutput(const QString &outDevDescr)
 
     auto* tmp = alOutDev;
     alOutDev = nullptr;
-    if (outDevDescr.isEmpty())
-        alOutDev = alcOpenDevice(nullptr);
-    else
-        alOutDev = alcOpenDevice(outDevDescr.toStdString().c_str());
 
-    if (alOutDev)
+    if (outDevDescr != "none")
     {
-        if (alContext && alcMakeContextCurrent(nullptr) == ALC_TRUE)
-            alcDestroyContext(alContext);
+        if (outDevDescr.isEmpty())
+            alOutDev = alcOpenDevice(nullptr);
+        else
+            alOutDev = alcOpenDevice(outDevDescr.toStdString().c_str());
 
-        if (tmp)
-            alcCloseDevice(tmp);
-
-        alContext = alcCreateContext(alOutDev, nullptr);
-        if (alcMakeContextCurrent(alContext))
+        if (alOutDev)
         {
-            alGenSources(1, &alMainSource);
+            if (alContext && alcMakeContextCurrent(nullptr) == ALC_TRUE)
+                alcDestroyContext(alContext);
+
+            if (tmp)
+                alcCloseDevice(tmp);
+
+            alContext = alcCreateContext(alOutDev, nullptr);
+            if (alcMakeContextCurrent(alContext))
+            {
+                alGenSources(1, &alMainSource);
+            }
+            else
+            {
+                qWarning() << "Cannot create output audio context";
+                alcCloseDevice(alOutDev);
+                return false;
+            }
         }
         else
         {
-            qWarning() << "Cannot create output audio context";
-            alcCloseDevice(alOutDev);
+            qWarning() << "Cannot open output audio device " + outDevDescr;
             return false;
         }
     }
     else
     {
-        qWarning() << "Cannot open output audio device " + outDevDescr;
-        return false;
+        closeOutput();
     }
 
     Core* core = Core::getInstance();
@@ -307,9 +318,6 @@ void Audio::closeOutput()
     qDebug() << "Closing output";
     QMutexLocker locker(&audioOutLock);
 
-    if (inputSubscriptions > 0)
-        return;
-
     if (alContext && alcMakeContextCurrent(nullptr) == ALC_TRUE)
     {
         alcDestroyContext(alContext);
@@ -472,6 +480,12 @@ bool Audio::isInputReady()
     return alInDev && inputSubscriptions;
 }
 
+bool Audio::isInputSubscribed()
+{
+    // No lock, inputSubscriptions is atomic!
+    return inputSubscriptions;
+}
+
 /**
 Returns true if the output device is open
 */

src/audio/audio.h

@@ -70,6 +70,7 @@ public:
     bool openOutput(const QString& outDevDescr);
 
     bool isInputReady();
+    bool isInputSubscribed();
     bool isOutputReady();
 
     static void createSource(ALuint* source);

src/widget/form/settings/avform.cpp

@@ -253,6 +253,7 @@ void AVForm::getAudioInDevices()
     QString settingsInDev = Settings::getInstance().getInDev();
     int inDevIndex = 0;
     bodyUI->inDevCombobox->clear();
+    bodyUI->inDevCombobox->addItem(tr("None"));
     const ALchar *pDeviceList = alcGetString(NULL, ALC_CAPTURE_DEVICE_SPECIFIER);
     if (pDeviceList)
     {
@@ -283,6 +284,7 @@ void AVForm::getAudioOutDevices()
     QString settingsOutDev = Settings::getInstance().getOutDev();
     int outDevIndex = 0;
     bodyUI->outDevCombobox->clear();
+    bodyUI->outDevCombobox->addItem(tr("None"));
     const ALchar *pDeviceList;
     if (alcIsExtensionPresent(NULL, "ALC_ENUMERATE_ALL_EXT") != AL_FALSE)
         pDeviceList = alcGetString(NULL, ALC_ALL_DEVICES_SPECIFIER);
@@ -314,22 +316,25 @@ void AVForm::getAudioOutDevices()
     bodyUI->outDevCombobox->setCurrentIndex(outDevIndex);
 }
 
-void AVForm::onInDevChanged(const QString &deviceDescriptor)
+void AVForm::onInDevChanged(QString deviceDescriptor)
 {
+    if (!bodyUI->inDevCombobox->currentIndex())
+        deviceDescriptor = "none";
     Settings::getInstance().setInDev(deviceDescriptor);
 
     Audio& audio = Audio::getInstance();
-    if (audio.isInputReady())
+    if (audio.isInputSubscribed())
         audio.openInput(deviceDescriptor);
 }
 
-void AVForm::onOutDevChanged(const QString& deviceDescriptor)
+void AVForm::onOutDevChanged(QString deviceDescriptor)
 {
+    if (!bodyUI->outDevCombobox->currentIndex())
+        deviceDescriptor = "none";
     Settings::getInstance().setOutDev(deviceDescriptor);
 
     Audio& audio = Audio::getInstance();
-    if (audio.isOutputReady())
-        audio.openOutput(deviceDescriptor);
+    audio.openOutput(deviceDescriptor);
 }
 
 void AVForm::onFilterAudioToggled(bool filterAudio)

src/widget/form/settings/avform.h

@@ -54,8 +54,8 @@ private:
 private slots:
 
     // audio
-    void onInDevChanged(const QString& deviceDescriptor);
-    void onOutDevChanged(const QString& deviceDescriptor);
+    void onInDevChanged(QString deviceDescriptor);
+    void onOutDevChanged(QString deviceDescriptor);
     void onFilterAudioToggled(bool filterAudio);
     void on_playbackSlider_valueChanged(int value);
     void on_microphoneSlider_valueChanged(int value);