Qt: Fix bounded fast forward with Qt Multimedia

CHANGES

@@ -25,6 +25,7 @@ Other fixes:
  - Wii: Fix aspect ratio (fixes mgba.io/i/500)
  - FFmpeg: Fix audio conversion producing gaps
  - GBA: Fix skipping BIOS on irregularly sized ROMs
+ - Qt: Fix bounded fast forward with Qt Multimedia
 Misc:
  - Qt: Add missing HEVC NVENC option (fixes mgba.io/i/1323)
  - Qt: Improve camera initialization

src/platform/qt/CoreController.cpp

@@ -434,13 +434,21 @@ void CoreController::rewind(int states) {
 }
 
 void CoreController::setFastForward(bool enable) {
+	if (m_fastForward == enable) {
+		return;
+	}
 	m_fastForward = enable;
 	updateFastForward();
+	emit fastForwardChanged(enable);
 }
 
 void CoreController::forceFastForward(bool enable) {
+	if (m_fastForwardForced == enable) {
+		return;
+	}
 	m_fastForwardForced = enable;
 	updateFastForward();
+	emit fastForwardChanged(enable || m_fastForward);
 }
 
 void CoreController::loadState(int slot) {

src/platform/qt/Window.cpp

@@ -907,6 +907,7 @@ void Window::reloadAudioDriver() {
 	m_audioProcessor->requestSampleRate(opts->sampleRate);
 	m_audioProcessor->start();
 	connect(m_controller.get(), &CoreController::stopping, m_audioProcessor.get(), &AudioProcessor::stop);
+	connect(m_controller.get(), &CoreController::fastForwardChanged, m_audioProcessor.get(), &AudioProcessor::inputParametersChanged);
 }
 
 void Window::tryMakePortable() {