Add support for DSP buffer size

README.md

@@ -523,6 +523,17 @@ Fmod.set_driver(id)
 var id = Fmod.get_driver()
 ```
 
+### Reducing audio playback latency
+
+You may encounter that the audio playback has some latency. This may be caused by the DSP buffer size. You can change the value **before** initialisation to adjust it:
+```gdscript
+Fmod.set_dsp_buffer_size(512, 4)
+# retrieve the buffer length
+Fmod.get_dsp_buffer_length()
+# retrieve the number of buffers
+Fmod.get_dsp_num_buffers()
+```
+
 ### Profiling & querying performance data
 
 `getPerformanceData` returns an object which contains current performance stats for CPU, Memory and File Streaming usage of both FMOD Studio and the Core System.

demo/addons/fmod/Fmod.gd

@@ -197,6 +197,15 @@ func get_global_parameter_desc_count() -> int:
 func get_global_parameter_desc_list() -> Array:
 	return godot_fmod.get_global_parameter_desc_list()
 
+func set_dsp_buffer_size(bufferLength: int, numberOfBuffers: int) -> void:
+    godot_fmod.set_dsp_buffer_size(bufferLength, numberOfBuffers)
+
+func get_dsp_buffer_length() -> int:
+	return godot_fmod.get_dsp_buffer_length()
+
+func set_dsp_num_buffers() -> int:
+	return godot_fmod.get_dsp_num_buffers()
+
 ###############
 ###LISTENERS###
 ###############

src/godot_fmod.cpp

@@ -136,6 +136,9 @@ void Fmod::_register_methods() {
     register_method("get_global_parameter_desc_by_id", &Fmod::getGlobalParameterDescByID);
     register_method("get_global_parameter_desc_count", &Fmod::getGlobalParameterDescCount);
     register_method("get_global_parameter_desc_list", &Fmod::getGlobalParameterDescList);
+    register_method("set_dsp_buffer_size", &Fmod::setSystemDSPBufferSize);
+    register_method("get_dsp_buffer_length", &Fmod::getSystemDSPBufferLength);
+    register_method("get_dsp_num_buffers", &Fmod::getSystemDSPNumBuffers);
     register_method("_process", &Fmod::_process);
 
     register_signal<Fmod>("timeline_beat", "params", GODOT_VARIANT_TYPE_DICTIONARY);
@@ -1313,6 +1316,24 @@ Node * Fmod::getObjectAttachedToInstance(uint64_t instanceId) {
     return node;
 }
 
+void Fmod::setSystemDSPBufferSize(unsigned int bufferlength, int numbuffers) {
+    if (bufferlength > 0 && numbuffers > 0 && ERROR_CHECK(coreSystem->setDSPBufferSize(bufferlength, numbuffers))) {
+        GODOT_LOG(0, "FMOD Sound System: Successfully set DSP buffer size")
+    } else {
+        GODOT_LOG(2, "FMOD Sound System: Failed to set DSP buffer size :|")
+    }
+}
+
+int Fmod::getSystemDSPBufferLength() {
+    ERROR_CHECK(coreSystem->getDSPBufferSize(&this->bufferlength, &this->numbuffers));
+    return this->bufferlength;
+}
+
+int Fmod::getSystemDSPNumBuffers() {
+    ERROR_CHECK(coreSystem->getDSPBufferSize(&this->bufferlength, &this->numbuffers));
+    return this->numbuffers;
+}
+
 void Fmod::pauseAllEvents(const bool pause) {
     for (int i = 0; i < events.size(); i++) {
         auto eventInstance = events.get(i);

src/godot_fmod.h

@@ -111,6 +111,8 @@ namespace godot {
         int actualListenerNumber = 0;
         Listener listeners[FMOD_MAX_LISTENERS];
         bool listenerWarning = true;
+        unsigned int bufferlength = 0;
+        int numbuffers = 0;
 
         Vector<LoadingBank *> loadingBanks;
         Map<String, FMOD::Studio::Bank *> banks;
@@ -183,6 +185,9 @@ namespace godot {
         void setListenerLock(int index, bool isLocked);
         bool getListenerLock(int index);
         Node* getObjectAttachedToListener(int index);
+        void setSystemDSPBufferSize(unsigned int bufferlength, int numbuffers);
+        int getSystemDSPBufferLength();
+        int getSystemDSPNumBuffers();
 
         String loadBank(String pathToBank, unsigned int flag);
         void unloadBank(String pathToBank);