audioWorklets proposal 2

addons/ofxEmscripten/src/ofxEmscriptenSoundStream.cpp

@@ -10,6 +10,55 @@
 #include "ofBaseApp.h"
 #include "ofLog.h"
 
+ofEvent<void> audioWorkletEvent;
+
+// This event will fire on the audio worklet thread.
+void MessageReceivedInAudioWorkletThread_1(int inputChannels, int outputChannels, int inbuffer) {
+	EM_ASM({globalThis.inputChannels = $0; globalThis.outputChannels = $1; globalThis.inbuffer = $2;}, inputChannels, outputChannels, inbuffer);
+}
+
+void MessageReceivedInAudioWorkletThread_2(int outbuffer, int stream_callback, int userData) {
+	EM_ASM({globalThis.outbuffer = $0; globalThis.stream_callback = $1; globalThis.userData = $2;}, outbuffer, stream_callback, userData);
+}
+
+EM_BOOL ProcessAudio(int numInputs, const AudioSampleFrame *inputs, int numOutputs, AudioSampleFrame *outputs, int numParams, const AudioParamFrame *params, void *userData) {
+	return EM_TRUE;
+}
+
+// This callback will fire after the Audio Worklet Processor has finished being added to the Worklet global scope.
+void AudioWorkletProcessorCreated(EMSCRIPTEN_WEBAUDIO_T audioContext, EM_BOOL success, void *userData) {
+	if (!success) return; 
+	// Specify the input and output node configurations for the Wasm Audio Worklet. A simple setup with single mono output channel here, and no inputs.
+	int outputChannelCounts[1] = { 2 };
+	EmscriptenAudioWorkletNodeCreateOptions options = {
+		.numberOfInputs = 1,
+		.numberOfOutputs = 1,
+		.outputChannelCounts = outputChannelCounts
+	};
+	// Instantiate the noise-generator Audio Worklet Processor.
+	EMSCRIPTEN_AUDIO_WORKLET_NODE_T audioWorklet = emscripten_create_wasm_audio_worklet_node(audioContext, "tone-generator", &options, &ProcessAudio, 0);
+	html5audio_stream_create(audioWorklet, 0);
+}
+
+// This callback will fire when the Wasm Module has been shared to the AudioWorklet global scope, and is now ready to begin adding Audio Worklet Processors.
+void WebAudioWorkletThreadInitialized(EMSCRIPTEN_WEBAUDIO_T audioContext, EM_BOOL success, void *userData) {
+	if (!success) return;
+	audioWorkletEvent.notify();
+	WebAudioWorkletProcessorCreateOptions opts = {
+		.name = "tone-generator",
+	};
+	emscripten_create_wasm_audio_worklet_processor_async(audioContext, &opts, AudioWorkletProcessorCreated, 0);
+}
+
+void ofxEmscriptenSoundStream::audioWorklet() {
+	emscripten_audio_worklet_post_function_viii(context, MessageReceivedInAudioWorkletThread_1, /*inputChannels=*/settings.numInputChannels, /*outputChannels=*/settings.numOutputChannels, /*inbuffer=*/EM_ASM_INT(return $0, inbuffer.getBuffer().data()));
+	emscripten_audio_worklet_post_function_viii(context, MessageReceivedInAudioWorkletThread_2, /*outbuffer=*/EM_ASM_INT(return $0, outbuffer.getBuffer().data()), /*stream_callback=*/EM_ASM_INT(return $0, &audio_cb), /*userData=*/EM_ASM_INT(return $0, this));
+}
+
+// Define a global stack space for the AudioWorkletGlobalScope. Note that all AudioWorkletProcessors and/or AudioWorkletNodes on the given Audio Context all share the same AudioWorkerGlobalScope,
+// i.e. they all run on the same one audio thread (multiple nodes/processors do not each get their own thread). Hence one stack is enough.
+uint8_t wasmAudioWorkletStack[4096];
+
 using namespace std;
 
 int ofxEmscriptenAudioContext();
@@ -31,10 +80,11 @@ std::vector<ofSoundDevice> ofxEmscriptenSoundStream::getDeviceList(ofSoundDevice
 }
 
 bool ofxEmscriptenSoundStream::setup(const ofSoundStreamSettings & settings) {
+	ofAddListener(audioWorkletEvent, this, &ofxEmscriptenSoundStream::audioWorklet);
 	inbuffer.allocate(settings.bufferSize, settings.numInputChannels);
 	outbuffer.allocate(settings.bufferSize, settings.numOutputChannels);
 	this->settings = settings;
-	html5audio_stream_create(settings.bufferSize,settings.numInputChannels,settings.numOutputChannels,inbuffer.getBuffer().data(),outbuffer.getBuffer().data(),&audio_cb,this);
+	emscripten_start_wasm_audio_worklet_thread_async(context, wasmAudioWorkletStack, sizeof(wasmAudioWorkletStack), WebAudioWorkletThreadInitialized, 0);
 	return true;
 }
 

addons/ofxEmscripten/src/ofxEmscriptenSoundStream.h

@@ -9,6 +9,8 @@
 
 #include "ofSoundBaseTypes.h"
 #include "ofSoundBuffer.h"
+#include "ofEvents.h"
+#include "emscripten/webaudio.h"
 
 class ofxEmscriptenSoundStream: public ofBaseSoundStream {
 public:
@@ -26,6 +28,7 @@ class ofxEmscriptenSoundStream: public ofBaseSoundStream {
 	void start();
 	void stop();
 	void close();
+	void audioWorklet();
 
 	uint64_t getTickCount() const;
 	int getNumInputChannels() const;

libs/openFrameworksCompiled/project/emscripten/config.emscripten.default.mk

@@ -64,8 +64,8 @@ PLATFORM_REQUIRED_ADDONS = ofxEmscripten
 ################################################################################
 
 # Code Generation Option Flags (http://gcc.gnu.org/onlinedocs/gcc/Code-Gen-Options.html)
-PLATFORM_CFLAGS =
-PLATFORM_CXXFLAGS = -Wall -std=c++17 -Wno-warn-absolute-paths
+PLATFORM_CFLAGS = -s USE_PTHREADS=1
+PLATFORM_CXXFLAGS = -Wall -std=c++17 -Wno-warn-absolute-paths -s USE_PTHREADS=1
 
 ################################################################################
 # PLATFORM LDFLAGS
@@ -93,7 +93,7 @@ ifdef USE_CCACHE
 	endif
 endif
 
-PLATFORM_LDFLAGS = -Wl --gc-sections --preload-file bin/data@data --emrun --bind --profiling-funcs -s USE_FREETYPE=1 -s ALLOW_MEMORY_GROWTH=1 -s MAX_WEBGL_VERSION=2 -s WEBGL2_BACKWARDS_COMPATIBILITY_EMULATION=1
+PLATFORM_LDFLAGS = -Wl --gc-sections --preload-file bin/data@data --emrun --bind --profiling-funcs -s USE_FREETYPE=1 -s ALLOW_MEMORY_GROWTH=0 -s MAX_WEBGL_VERSION=2 -s WEBGL2_BACKWARDS_COMPATIBILITY_EMULATION=1 -s FULL_ES2 -sFULL_ES3=1 -s USE_PTHREADS=1 -s AUDIO_WORKLET=1 -s WASM_WORKERS=1 -sENVIRONMENT="web,worker" -s WEBAUDIO_DEBUG=1
 PLATFORM_LDFLAGS += --js-library $(OF_ADDONS_PATH)/ofxEmscripten/libs/html5video/lib/emscripten/library_html5video.js
 PLATFORM_LDFLAGS += --js-library $(OF_ADDONS_PATH)/ofxEmscripten/libs/html5audio/lib/emscripten/library_html5audio.js
 
@@ -105,7 +105,7 @@ endif
 
 PLATFORM_OPTIMIZATION_LDFLAGS_RELEASE = -O3 -s TOTAL_MEMORY=$(PLATFORM_EMSCRIPTEN_TOTAL_MEMORY) --memory-init-file 1
 
-PLATFORM_OPTIMIZATION_LDFLAGS_DEBUG = -g3 -s TOTAL_MEMORY=134217728 --memory-init-file 1  -s DEMANGLE_SUPPORT=1 -s ASSERTIONS=2
+PLATFORM_OPTIMIZATION_LDFLAGS_DEBUG = -g3 -s TOTAL_MEMORY=134217728 --memory-init-file 1 -s DEMANGLE_SUPPORT=1 -s ASSERTIONS=2
 
 ################################################################################
 # PLATFORM OPTIMIZATION CFLAGS