ASIO backend, part 6

add support for handling device resets
this will be extended to the SDL and PortAudio backends soon

src/audio/abstract.cpp

@@ -37,6 +37,14 @@ void* TAAudio::getContext() {
   return NULL;
 }
 
+TAAudioDeviceStatus TAAudio::getDeviceStatus() {
+  return deviceStatus;
+}
+
+void TAAudio::acceptDeviceStatus() {
+  deviceStatus=TA_AUDIO_DEVICE_OK;
+}
+
 bool TAAudio::quit() {
   return true;
 }
@@ -121,4 +129,4 @@ TAMidiIn::~TAMidiIn() {
 }
 
 TAMidiOut::~TAMidiOut() {
-}
+}

src/audio/asio.cpp

@@ -36,6 +36,36 @@ static void _onSampleRate(ASIOSampleRate rate) {
 }
 
 static long _onMessage(long type, long value, void* msg, double* opt) {
+  if (callbackInstance==NULL) return;
+  switch (type) {
+    case kAsioSelectorSupported:
+      switch (value) {
+        case kAsioSelectorSupported:
+        case kAsioEngineVersion:
+        case kAsioResetRequest:
+        case kAsioBufferSizeChange:
+        case kAsioResyncRequest:
+          return 1;
+        default:
+          return 0;
+      }
+      break;
+    case kAsioEngineVersion:
+      return 2;
+      break;
+    case kAsioResetRequest:
+      callbackInstance->requestDeviceChange();
+      return 1;
+      break;
+    case kAsioBufferSizeChange:
+      callbackInstance->onBufferSize(value);
+      return 1;
+      break;
+    case kAsioResyncRequest:
+      // ignore
+      return 1;
+      break;
+  }
   return 0;
 }
 
@@ -343,6 +373,10 @@ bool TAAudioASIO::setRun(bool run) {
   return running;
 }
 
+void TAAudioASIO::requestDeviceChange() {
+  deviceStatus=TA_AUDIO_DEVICE_RESET;
+}
+
 bool TAAudioASIO::init(TAAudioDesc& request, TAAudioDesc& response) {
   if (initialized) return false;
   if (callbackInstance) {

src/audio/asio.h

@@ -41,6 +41,7 @@ class TAAudioASIO: public TAAudio {
     void onSampleRate(double rate);
     void onBufferSize(int bufsize);
     void onProcess(int nframes);
+    void requestDeviceChange();
 
     String getErrorStr(ASIOError which);
     String getFormatName(ASIOSampleType which);

src/audio/taAudio.h

@@ -36,6 +36,15 @@ struct BufferSizeChangeEvent {
     bufsize(bs) {}
 };
 
+enum TAAudioDeviceStatus {
+  // device is working
+  TA_AUDIO_DEVICE_OK=0,
+  // device has reset - reload audio engine
+  TA_AUDIO_DEVICE_RESET,
+  // device has been removed - reload audio engine with another device
+  TA_AUDIO_DEVICE_REMOVED
+};
+
 enum TAAudioFormat {
   TA_AUDIO_FORMAT_F32=0,
   TA_AUDIO_FORMAT_F64,
@@ -157,6 +166,8 @@ class TAAudio {
   protected:
     TAAudioDesc desc;
     TAAudioFormat outFormat;
+    TAAudioDeviceStatus deviceStatus;
+
     bool running, initialized;
     float** inBufs;
     float** outBufs;
@@ -176,12 +187,15 @@ class TAAudio {
     virtual bool quit();
     virtual bool setRun(bool run);
     virtual std::vector<String> listAudioDevices();
+    TAAudioDeviceStatus getDeviceStatus();
+    void acceptDeviceStatus();
     bool initMidi(bool jack);
     void quitMidi();
     virtual bool init(TAAudioDesc& request, TAAudioDesc& response);
 
     TAAudio():
       outFormat(TA_AUDIO_FORMAT_F32),
+      deviceStatus(TA_AUDIO_DEVICE_OK),
       running(false),
       initialized(false),
       inBufs(NULL),

src/engine/engine.cpp

@@ -3798,6 +3798,16 @@ TAAudioDesc& DivEngine::getAudioDescGot() {
   return got;
 }
 
+TAAudioDeviceStatus DivEngine::getAudioDeviceStatus() {
+  if (output==NULL) return TA_AUDIO_DEVICE_OK;
+  return output->getDeviceStatus();
+}
+
+void DivEngine::acceptAudioDeviceStatus() {
+  if (output==NULL) return;
+  output->acceptDeviceStatus();
+}
+
 std::vector<String>& DivEngine::getAudioDevices() {
   return audioDevs;
 }

src/engine/engine.h

@@ -1403,6 +1403,12 @@ class DivEngine {
     // get audio desc
     TAAudioDesc& getAudioDescGot();
 
+    // get audio device status
+    TAAudioDeviceStatus getAudioDeviceStatus();
+
+    // acknowledge an audio device status change
+    void acceptAudioDeviceStatus();
+
     // init dispatch
     void initDispatch(bool isRender=false);
 

src/gui/gui.cpp

@@ -4333,6 +4333,17 @@ bool FurnaceGUI::loop() {
       });
     }
 
+    // recover from audio resets
+    TAAudioDeviceStatus audioStatus=e->getAudioDeviceStatus();
+    if (audioStatus!=TA_AUDIO_DEVICE_OK) {
+      logI("audio device reset!");
+      e->acceptAudioDeviceStatus();
+
+      if (!e->switchMaster(false)) {
+        showError(_("audio device has reset or has been disconnected! check audio settings."));
+      }
+    }
+
     // recover from dead graphics
     if (rend->isDead() || killGraphics) {
       killGraphics=false;