fix crash when no output audio device selected, add get/set volume support for input devices

interface/src/Audio.cpp

@@ -395,7 +395,7 @@ void Audio::handleAudioInput() {
     if (Menu::getInstance()->isOptionChecked(MenuOption::EchoLocalAudio) && !_muted) {
         // if this person wants local loopback add that to the locally injected audio
 
-        if (!_loopbackOutputDevice) {
+        if (!_loopbackOutputDevice && _loopbackAudioOutput) {
             // we didn't have the loopback output device going so set that up now
             _loopbackOutputDevice = _loopbackAudioOutput->start();
         }
@@ -545,7 +545,7 @@ void Audio::handleAudioInput() {
         addProceduralSounds(monoAudioSamples,
                             NETWORK_BUFFER_LENGTH_SAMPLES_PER_CHANNEL);
         
-        if (!_proceduralOutputDevice) {
+        if (!_proceduralOutputDevice && _proceduralAudioOutput) {
             _proceduralOutputDevice = _proceduralAudioOutput->start();
         }
         
@@ -645,7 +645,7 @@ void Audio::addReceivedAudioToBuffer(const QByteArray& audioByteArray) {
     static float networkOutputToOutputRatio = (_desiredOutputFormat.sampleRate() / (float) _outputFormat.sampleRate())
         * (_desiredOutputFormat.channelCount() / (float) _outputFormat.channelCount());
     
-    if (!_ringBuffer.isStarved() && _audioOutput->bytesFree() == _audioOutput->bufferSize()) {
+    if (!_ringBuffer.isStarved() && _audioOutput && _audioOutput->bytesFree() == _audioOutput->bufferSize()) {
         // we don't have any audio data left in the output buffer
         // we just starved
         //qDebug() << "Audio output just starved.";

interface/src/Audio.h

@@ -20,6 +20,7 @@
 #include "InterfaceConfig.h"
 
 #include <QAudio>
+#include <QAudioInput>
 #include <QGLWidget>
 #include <QtCore/QObject>
 #include <QtCore/QVector>
@@ -92,6 +93,9 @@ public slots:
     QString getDefaultDeviceName(QAudio::Mode mode);
     QVector<QString> getDeviceNames(QAudio::Mode mode);
 
+    float getInputVolume() const { return (_audioInput) ? _audioInput->volume() : 0.0f; }
+    void setInputVolume(float volume) { if (_audioInput) _audioInput->setVolume(volume); }
+
 signals:
     bool muteToggled();
     

interface/src/scripting/AudioDeviceScriptingInterface.cpp

@@ -58,3 +58,12 @@ QVector<QString> AudioDeviceScriptingInterface::getInputDevices() {
 QVector<QString> AudioDeviceScriptingInterface::getOutputDevices() {
     return Application::getInstance()->getAudio()->getDeviceNames(QAudio::AudioOutput);
 }
+
+
+float AudioDeviceScriptingInterface::getInputVolume() {
+    return Application::getInstance()->getAudio()->getInputVolume();
+}
+
+void AudioDeviceScriptingInterface::setInputVolume(float volume) {
+    Application::getInstance()->getAudio()->setInputVolume(volume);
+}

interface/src/scripting/AudioDeviceScriptingInterface.h

@@ -33,6 +33,9 @@ public slots:
 
     QVector<QString> getInputDevices();
     QVector<QString> getOutputDevices();
+
+    float getInputVolume();
+    void setInputVolume(float volume);
 };
 
 #endif /* defined(__hifi__AudioDeviceScriptingInterface__) */