hacky fix for QAudioOutput leftovers

xybrid/audio/audioengine.cpp

@@ -14,6 +14,7 @@ using namespace Xybrid::Data;
 #include <QDebug>
 #include <QThread>
 #include <QMutex>
+#include <QTimer>
 
 // zero-initialize
 AudioEngine* Xybrid::Audio::audioEngine = nullptr;
@@ -101,8 +102,12 @@ void AudioEngine::initAudio(bool startNow) {
 
 void AudioEngine::deinitAudio() {
     if (output) {
-        output->stop();
-        output.reset();
+        QTimer::singleShot(20, [this] { // delay to flush buffers with silence, else we get leftovers on next playback
+            if (output && mode == Stopped) {
+                output->stop();
+                output.reset();
+            }
+        });
     }
 }
 
@@ -129,8 +134,6 @@ void AudioEngine::play(std::shared_ptr<Project> p) {
 
         output->start(this);
 
-        //tickId = 0; // actually, no reason to reset this
-
         mode = Playing;
         emit this->playbackModeChanged();
     }, Qt::QueuedConnection);
@@ -141,6 +144,7 @@ void AudioEngine::stop() {
         project = nullptr;
         queueValid = false;
         queue.clear();
+        for (auto& b : buffer) b.clear();
         deinitAudio();
         mode = Stopped;
         emit this->playbackModeChanged();
@@ -277,20 +281,18 @@ qint64 AudioEngine::readData(char *data, qint64 maxlen) {
         data += stride;
         sr -= stride;
     }
-
     return maxlen - sr;
 }
 
 void AudioEngine::nextTick() {
     bufPos = 0;
 
-    if (mode == Paused) { // simplest case, just give a 100ms empty buffer
+    if (mode == Paused || mode == Stopped) { // simplest case, just give a 100ms empty buffer
         buffer[0].clear();
         buffer[1].clear();
         buffer[0].resize(static_cast<size_t>(sampleRate/10));
         buffer[1].resize(static_cast<size_t>(sampleRate/10));
     } else if (mode == Previewing) {
-        // WIP
         // reset raw buffer
         tickBufPtr = tickBuf.get();
         tickId++;