Fix issues with changing default audio device

ScStwLibraries/ScStwLibraries.pri

@@ -15,6 +15,11 @@ ScStwLibraries_ClientLibs {
     DEFINES += ScStwLibraries_ClientLibs
 }
 
+ScStwLibraries_Raspi {
+    LIBS += -lasound
+    DEFINES += ScStwLibraries_Raspi
+}
+
 INCLUDEPATH += $$PWD/headers $$PWD
 
 SOURCES += \

ScStwLibraries/headers/scstwsoundplayer.h

@@ -27,9 +27,10 @@
 #include <QTimer>
 #include <QDateTime>
 #include <QSoundEffect>
+#include <QAudioDeviceInfo>
 
-#ifdef RASPI
-#include <QProcess>
+#ifdef ScStwLibraries_Raspi
+#include <alsa/asoundlib.h>
 #endif
 
 /*!
@@ -60,6 +61,11 @@ public:
     };
 
 private:
+
+    bool _setSoundVolume(double volume);
+
+    void _initializeSondEffect();
+
     /*!
      * \brief A map containing all sound files
      * 0: AtYourMarksSound
@@ -74,6 +80,8 @@ private:
      */
     QSoundEffect *soundEffect;
 
+    QAudioDeviceInfo *_audioOutputDevice;
+
     /*!
      * \brief The QEventLoop used to wait for the sound to finish
      */

ScStwLibraries/sources/scstwsoundplayer.cpp

@@ -28,8 +28,7 @@ ScStwSoundPlayer::ScStwSoundPlayer(QObject *parent) : QObject(parent)
     this->soundFiles.insert(Start, {{"path","qrc:/sound/StartsignalSoundExtended.wav"}, {"duration", 3200}});
     this->soundFiles.insert(FalseStart, {{"path","qrc:/sound/FalseStartSound.wav"}, {"duration", 2000}});
 
-    this->soundEffect = new QSoundEffect(this);
-    this->soundEffect->setLoopCount(1);
+    this->_initializeSondEffect();
 
     connect(this, &ScStwSoundPlayer::playbackStarted, this->waitLoop, &QEventLoop::quit);
     connect(this->soundEffect, &QSoundEffect::playingChanged, this->waitLoop, &QEventLoop::quit);
@@ -48,28 +47,8 @@ ScStwSoundPlayer::PlayResult ScStwSoundPlayer::play(ScStwSoundPlayer::StartSound
     // update currently playing action
     this->currentlyPlayingSound = sound;
 
-#ifdef RASPI
-    // set volume on raspi using amixer
-    QProcess soundProcess;
-
-    // determine current audio output device
-    soundProcess.start("amixer", {"scontrols"});
-    soundProcess.waitForFinished();
-    QStringList outputDeviceNameList = QString(soundProcess.readAllStandardOutput()).split("'");
-
-    if(outputDeviceNameList.length() == 3) {
-        QString outputDeviceName = outputDeviceNameList[1];
-        soundProcess.execute("amixer", {"sset", outputDeviceName, QString::number(volume * 100, 'f', 0) + "%"});
-    }
-    else {
-        qDebug() << "[WARNING][SoundPlayer] Could not determine output device to set volume";
+    if(!this->_setSoundVolume(volume))
         return Error;
-    }
-
-    this->soundEffect->setVolume(1);
-#else
-    this->soundEffect->setVolume(volume);
-#endif
 
     // load
     this->soundEffect->setSource(this->soundFiles[sound]["path"].toString());
@@ -145,3 +124,89 @@ ScStwSoundPlayer::PlayResult ScStwSoundPlayer::waitForSoundFinish(double *timeOf
 bool ScStwSoundPlayer::isPlaying() {
     return this->soundEffect->isPlaying();
 }
+
+#ifdef ScStwLibraries_Raspi
+void ScStwSoundPlayer::_initializeSondEffect() {
+    this->_audioOutputDevice = nullptr;
+    for(QAudioDeviceInfo info : QAudioDeviceInfo::availableDevices(QAudio::AudioOutput)) {
+        qDebug() << info.deviceName();
+        if(info.deviceName().contains("Headphones"))
+            this->_audioOutputDevice = new QAudioDeviceInfo(info);
+    }
+
+    if(this->_audioOutputDevice == nullptr)
+        this->_audioOutputDevice = new QAudioDeviceInfo(QAudioDeviceInfo::defaultOutputDevice());
+
+    this->soundEffect = new QSoundEffect(*this->_audioOutputDevice, this);
+    this->soundEffect->setLoopCount(1);
+}
+#else
+void ScStwSoundPlayer::_initializeSondEffect() {
+    this->_audioOutputDevice = new QAudioDeviceInfo(QAudioDeviceInfo::defaultOutputDevice());
+    this->soundEffect = new QSoundEffect(*this->_audioOutputDevice, this);
+    this->soundEffect->setLoopCount(1);
+}
+#endif
+
+#ifdef ScStwLibraries_Raspi
+bool ScStwSoundPlayer::_setSoundVolume(double volume) {
+
+    QString cardName = this->_audioOutputDevice->deviceName();
+    QStringRef shortCardName = cardName.midRef(cardName.indexOf(QLatin1String("="), 0) + 1);
+
+    int cardIndex = snd_card_get_index(shortCardName.toLocal8Bit().constData());
+    QString soundDevice = QString(QLatin1String("hw:%1")).arg(cardIndex);
+    qDebug() << "[INFO][SoundPlayer] Using audio device: " << soundDevice;
+
+    long min, max;
+    snd_mixer_t *handle;
+    snd_mixer_selem_id_t *sid;
+    snd_mixer_elem_t *elem;
+
+    if(snd_mixer_open(&handle, 0) < 0) {
+        qDebug() << "[ERROR][SoundPlayer] Could not open mixer";
+        return false;
+    }
+    if(snd_mixer_selem_register(handle, NULL, NULL)  < 0) {
+        qDebug() << "[ERROR][SoundPlayer] Could not register selem";
+        return false;
+    }
+    if(snd_mixer_attach(handle, soundDevice.toStdString().c_str()) < 0) {
+        qDebug() << "[ERROR][SoundPlayer] Could not attach mixer";
+        return false;
+    }
+    if(snd_mixer_load(handle) < 0) {
+        qDebug() << "[ERROR][SoundPlayer] Could not load mixer";
+        return false;
+    }
+
+    // set volume for all channels
+    snd_mixer_selem_id_alloca(&sid);
+    bool success = false;
+    for (elem = snd_mixer_first_elem(handle); elem; elem = snd_mixer_elem_next(elem)) {
+        snd_mixer_selem_get_id(elem, sid);
+        if (!snd_mixer_selem_is_active(elem))
+            continue;
+
+        elem = snd_mixer_find_selem(handle, sid);
+        if(!elem)
+            continue;
+
+        snd_mixer_selem_get_playback_volume_range(elem, &min, &max);
+        snd_mixer_selem_set_playback_volume_all(elem, min + (volume) * (max - min));
+
+        success = true;
+    }
+
+    snd_mixer_close(handle);
+
+    this->soundEffect->setVolume(1);
+
+    return success;
+}
+#else
+bool ScStwSoundPlayer::_setSoundVolume(double volume) {
+    this->soundEffect->setVolume(volume);
+    return true;
+}
+#endif