Implement device config changes at runtime (juce and jack)

resources/ui/carla_settings_driver.ui

@@ -37,7 +37,7 @@
      </property>
      <property name="sizeHint" stdset="0">
       <size>
-       <width>1</width>
+       <width>40</width>
        <height>1</height>
       </size>
      </property>
@@ -61,6 +61,9 @@
      <property name="orientation">
       <enum>Qt::Horizontal</enum>
      </property>
+     <property name="sizeType">
+      <enum>QSizePolicy::Fixed</enum>
+     </property>
      <property name="sizeHint" stdset="0">
       <size>
        <width>40</width>
@@ -94,10 +97,13 @@
      <property name="orientation">
       <enum>Qt::Horizontal</enum>
      </property>
+     <property name="sizeType">
+      <enum>QSizePolicy::Fixed</enum>
+     </property>
      <property name="sizeHint" stdset="0">
       <size>
        <width>40</width>
-       <height>20</height>
+       <height>1</height>
       </size>
      </property>
     </spacer>

source/backend/CarlaEngine.hpp

@@ -837,8 +837,16 @@ public:
      */
     virtual void clearXruns() const noexcept;
 
+    /*!
+     * Dynamically change buffer size and/or sample rate while engine is running.
+     * @see ENGINE_DRIVER_DEVICE_VARIABLE_BUFFER_SIZE
+     * @see ENGINE_DRIVER_DEVICE_VARIABLE_SAMPLE_RATE
+     */
+    virtual bool setBufferSizeAndSampleRate(const uint bufferSize, const double sampleRate);
+
     /*!
      * Show the custom control panel for the current engine device.
+     * @see ENGINE_DRIVER_DEVICE_HAS_CONTROL_PANEL
      */
     virtual bool showDeviceControlPanel() const noexcept;
 

source/backend/CarlaHost.h

@@ -427,8 +427,16 @@ CARLA_EXPORT const CarlaRuntimeEngineInfo* carla_get_runtime_engine_info();
  */
 CARLA_EXPORT const CarlaRuntimeEngineDriverDeviceInfo* carla_get_runtime_engine_driver_device_info();
 
+/*!
+ * Dynamically change buffer size and/or sample rate while engine is running.
+ * @see ENGINE_DRIVER_DEVICE_VARIABLE_BUFFER_SIZE
+ * @see ENGINE_DRIVER_DEVICE_VARIABLE_SAMPLE_RATE
+ */
+CARLA_EXPORT bool carla_set_engine_buffer_size_and_sample_rate(uint bufferSize, double sampleRate);
+
 /*!
  * Show the custom control panel for the current engine device.
+ * @see ENGINE_DRIVER_DEVICE_HAS_CONTROL_PANEL
  */
 CARLA_EXPORT bool carla_show_engine_device_control_panel();
 

source/backend/CarlaStandalone.cpp

@@ -541,6 +541,14 @@ const CarlaRuntimeEngineDriverDeviceInfo* carla_get_runtime_engine_driver_device
     return &retInfo;
 }
 
+bool carla_set_engine_buffer_size_and_sample_rate(uint bufferSize, double sampleRate)
+{
+    CARLA_SAFE_ASSERT_RETURN(gStandalone.engine != nullptr, false);
+    carla_debug("carla_set_engine_buffer_size_and_sample_rate(%u, %f)", bufferSize, sampleRate);
+
+    return gStandalone.engine->setBufferSizeAndSampleRate(bufferSize, sampleRate);
+}
+
 bool carla_show_engine_device_control_panel()
 {
     CARLA_SAFE_ASSERT_RETURN(gStandalone.engine != nullptr, false);

source/backend/engine/CarlaEngine.cpp

@@ -410,6 +410,11 @@ bool CarlaEngine::showDeviceControlPanel() const noexcept
     return false;
 }
 
+bool CarlaEngine::setBufferSizeAndSampleRate(const uint, const double)
+{
+    return false;
+}
+
 // -----------------------------------------------------------------------
 // Plugin management
 

source/backend/engine/CarlaEngineJack.cpp

@@ -1191,6 +1191,16 @@ public:
     }
 #endif
 
+    bool setBufferSizeAndSampleRate(const uint bufferSize, const double sampleRate) override
+    {
+        CARLA_SAFE_ASSERT_RETURN(carla_isEqual(pData->sampleRate, sampleRate), false);
+        CARLA_SAFE_ASSERT_RETURN(fClient != nullptr, false);
+
+        try {
+            return jackbridge_set_buffer_size(fClient, bufferSize);
+        } CARLA_SAFE_EXCEPTION_RETURN("setBufferSizeAndSampleRate", false);
+    }
+
     EngineTimeInfo getTimeInfo() const noexcept override
     {
         if (pData->options.transportMode != ENGINE_TRANSPORT_MODE_JACK)

source/backend/engine/CarlaEngineJuce.cpp

@@ -352,6 +352,69 @@ public:
         pData->xruns = xruns > 0 ? static_cast<uint32_t>(xruns) : 0;
     }
 
+    bool setBufferSizeAndSampleRate(const uint bufferSize, const double sampleRate) override
+    {
+        CARLA_SAFE_ASSERT_RETURN(fDevice != nullptr, false);
+
+        juce::StringArray inputNames(fDevice->getInputChannelNames());
+        juce::StringArray outputNames(fDevice->getOutputChannelNames());
+
+        if (inputNames.size() < 0 || outputNames.size() <= 0)
+        {
+            setLastError("Selected device does not have any outputs");
+            return false;
+        }
+
+        juce::BigInteger inputChannels;
+        inputChannels.setRange(0, inputNames.size(), true);
+
+        juce::BigInteger outputChannels;
+        outputChannels.setRange(0, outputNames.size(), true);
+
+        // stop stream first
+        if (fDevice->isPlaying())
+            fDevice->stop();
+        if (fDevice->isOpen())
+            fDevice->close();
+
+        juce::String error = fDevice->open(inputChannels, outputChannels, sampleRate, static_cast<int>(bufferSize));
+
+        if (error.isNotEmpty())
+        {
+            setLastError(error.toUTF8());
+
+            // try to roll back
+            error = fDevice->open(inputChannels, outputChannels, pData->sampleRate, static_cast<int>(pData->bufferSize));
+
+            // if we failed, we are screwed...
+            if (error.isNotEmpty())
+            {
+                fDevice = nullptr;
+                close();
+            }
+
+            return false;
+        }
+
+        const uint32_t newBufferSize = static_cast<uint32_t>(fDevice->getCurrentBufferSizeSamples());
+        const double   newSampleRate = fDevice->getCurrentSampleRate();
+
+        if (carla_isNotEqual(pData->sampleRate, newSampleRate))
+        {
+            pData->sampleRate = newSampleRate;
+            sampleRateChanged(newSampleRate);
+        }
+
+        if (pData->bufferSize != newBufferSize)
+        {
+            pData->bufferSize = newBufferSize;
+            bufferSizeChanged(newBufferSize);
+        }
+
+        fDevice->start(this);
+        return true;
+    }
+
     bool showDeviceControlPanel() const noexcept override
     {
         try {

source/backend/engine/CarlaEngineNative.cpp

@@ -2738,6 +2738,7 @@ uint               CarlaEngine::getJuceApiCount()                 { return 0;
 const char*        CarlaEngine::getJuceApiName(const uint)        { return nullptr; }
 const char* const* CarlaEngine::getJuceApiDeviceNames(const uint) { return nullptr; }
 const EngineDriverDeviceInfo* CarlaEngine::getJuceDeviceInfo(const uint, const char* const) { return nullptr; }
+bool               CarlaEngine::showJuceDeviceControlPanel(const uint, const char* const)   { return false; }
 # else
 CarlaEngine*       CarlaEngine::newRtAudio(const AudioApi)           { return nullptr; }
 uint               CarlaEngine::getRtAudioApiCount()                 { return 0;       }

source/frontend/carla_backend.py

@@ -1508,7 +1508,14 @@ class CarlaHostMeta(object):
     def get_runtime_engine_driver_device_info(self):
         raise NotImplementedError
 
+    # Dynamically change buffer size and/or sample rate while engine is running.
+    # @see ENGINE_DRIVER_DEVICE_VARIABLE_BUFFER_SIZE
+    # @see ENGINE_DRIVER_DEVICE_VARIABLE_SAMPLE_RATE
+    def set_engine_buffer_size_and_sample_rate(self, bufferSize, sampleRate):
+        raise NotImplementedError
+
     # Show the custom control panel for the current engine device.
+    # @see ENGINE_DRIVER_DEVICE_HAS_CONTROL_PANEL
     def show_engine_device_control_panel(self):
         raise NotImplementedError
 
@@ -2168,6 +2175,9 @@ class CarlaHostNull(CarlaHostMeta):
     def get_runtime_engine_driver_device_info(self):
         return PyCarlaRuntimeEngineDriverDeviceInfo
 
+    def set_engine_buffer_size_and_sample_rate(self, bufferSize, sampleRate):
+        return False
+
     def show_engine_device_control_panel(self):
         return False
 
@@ -2477,6 +2487,9 @@ class CarlaHostDLL(CarlaHostMeta):
         self.lib.carla_get_runtime_engine_driver_device_info.argtypes = None
         self.lib.carla_get_runtime_engine_driver_device_info.restype = POINTER(CarlaRuntimeEngineDriverDeviceInfo)
 
+        self.lib.carla_set_engine_buffer_size_and_sample_rate.argtypes = [c_uint, c_double]
+        self.lib.carla_set_engine_buffer_size_and_sample_rate.restype = c_bool
+
         self.lib.carla_show_engine_device_control_panel.argtypes = None
         self.lib.carla_show_engine_device_control_panel.restype = c_bool
 
@@ -2776,6 +2789,9 @@ class CarlaHostDLL(CarlaHostMeta):
     def get_runtime_engine_driver_device_info(self):
         return structToDict(self.lib.carla_get_runtime_engine_driver_device_info().contents)
 
+    def set_engine_buffer_size_and_sample_rate(self, bufferSize, sampleRate):
+        return bool(self.lib.carla_set_engine_buffer_size_and_sample_rate(bufferSize, sampleRate))
+
     def show_engine_device_control_panel(self):
         return bool(self.lib.carla_show_engine_device_control_panel())
 
@@ -3166,6 +3182,9 @@ class CarlaHostPlugin(CarlaHostMeta):
     def get_runtime_engine_driver_device_info(self):
         return PyCarlaRuntimeEngineDriverDeviceInfo
 
+    def set_engine_buffer_size_and_sample_rate(self, bufferSize, sampleRate):
+        return False
+
     def show_engine_device_control_panel(self):
         return False
 

source/frontend/carla_host.py

@@ -877,6 +877,9 @@ class HostWindow(QMainWindow):
             QMessageBox.warning(self, self.tr("Warning"), self.tr("Engine was stopped while configuring settings, all changes have been ignored"))
             return
 
+        bufferSize, sampleRate = dialog.getValues()
+        self.host.set_engine_buffer_size_and_sample_rate(bufferSize, sampleRate)
+
     @pyqtSlot()
     def slot_engineStopTryAgain(self):
         if self.host.is_engine_running() and not self.host.set_engine_about_to_close():

source/frontend/carla_settings.py

@@ -281,9 +281,9 @@ class RuntimeDriverSettingsW(QDialog):
         bufferSize = self.ui.cb_buffersize.currentText()
         sampleRate = self.ui.cb_samplerate.currentText()
 
-        if bufferSize == self.AUTOMATIC_OPTION:
+        if bufferSize == DriverSettingsW.AUTOMATIC_OPTION:
             bufferSize = "0"
-        if sampleRate == self.AUTOMATIC_OPTION:
+        if sampleRate == DriverSettingsW.AUTOMATIC_OPTION:
             sampleRate = "0"
 
         return (int(bufferSize), int(sampleRate))