From e1dbbf816561886ca6b1cb22fd2ad916ad6292ef Mon Sep 17 00:00:00 2001
From: weil <weil@cybryda.org>
Date: Sun, 14 Jul 2024 06:22:52 +0200
Subject: [PATCH] Introduce extremely simplistic audio capturing mechanism

---
 src/AudioCapture.cpp   | 149 +++++++++++++++++++++++++++++++++++++++++
 src/AudioCapture.h     |  39 +++++++++++
 src/register_types.cpp |   2 +
 3 files changed, 190 insertions(+)
 create mode 100644 src/AudioCapture.cpp
 create mode 100644 src/AudioCapture.h

diff --git a/src/AudioCapture.cpp b/src/AudioCapture.cpp
new file mode 100644
index 0000000..c79459c
--- /dev/null
+++ b/src/AudioCapture.cpp
@@ -0,0 +1,149 @@
+#include "AudioCapture.h"
+
+#include <windows.h>
+#include <mmdeviceapi.h>
+#include <audioclient.h>
+#include <iostream>
+
+#include <godot_cpp/variant/utility_functions.hpp>
+
+namespace godot {
+
+
+void AudioCapture::_bind_methods()
+{
+  ClassDB::bind_method(D_METHOD("process"), &AudioCapture::process);
+  ClassDB::bind_method(D_METHOD("start"), &AudioCapture::start);
+  ClassDB::bind_method(D_METHOD("get_frame"), &AudioCapture::getFrame);
+}
+
+AudioCapture::AudioCapture()
+{
+  UtilityFunctions::print("BEDZIE RUCHANES");
+
+  HRESULT hr;
+  IMMDeviceEnumerator* pEnumerator = nullptr;
+  IMMDevice* pDevice = nullptr;
+
+  hr = CoInitialize(nullptr);
+  if (FAILED(hr)) {
+    UtilityFunctions::printerr("CoInitialize failed:", hr);
+    return;
+  }
+
+  hr = CoCreateInstance(__uuidof(MMDeviceEnumerator), nullptr, CLSCTX_ALL, IID_PPV_ARGS(&pEnumerator));
+  if (FAILED(hr)) {
+    UtilityFunctions::printerr("CoCreateInstance failed:", hr);
+    return;
+  }
+
+  hr = pEnumerator->GetDefaultAudioEndpoint(eRender, eConsole, &pDevice);
+  if (FAILED(hr)) {
+    UtilityFunctions::printerr("GetDefaultAudioEndpoint failed:", hr);
+    return;
+  }
+
+  hr = pDevice->Activate(__uuidof(IAudioClient), CLSCTX_ALL, nullptr, (void**)&m_audioClient);
+  if (FAILED(hr)) {
+    UtilityFunctions::printerr("Device activate failed:", hr);
+    return;
+  }
+
+  WAVEFORMATEX* pwfx{nullptr};
+  hr = m_audioClient->GetMixFormat(&pwfx);
+  if (FAILED(hr)) {
+    UtilityFunctions::printerr("GetMixFormat failed:", hr);
+    return;
+  }
+
+  hr = m_audioClient->Initialize(AUDCLNT_SHAREMODE_SHARED, AUDCLNT_STREAMFLAGS_LOOPBACK, 10000000, 0, pwfx, nullptr);
+  if (FAILED(hr)) {
+    UtilityFunctions::printerr("Device initialize failed:", hr);
+    return;
+  };
+
+  hr = m_audioClient->GetService(IID_PPV_ARGS(&m_captureClient));
+  if (FAILED(hr)) {
+    UtilityFunctions::printerr("Get service failed:", hr);
+    return;
+  }
+
+  UtilityFunctions::print("Gites majonez");
+}
+
+Array AudioCapture::getFrame() const
+{
+  // TODO: common pre-resized buffer?
+  Array out{};
+
+  UINT32 len = 0;
+  UINT32 frames = 0;
+  DWORD flags = 0;
+
+  m_captureClient->GetNextPacketSize(&len);
+
+  if (len > 0) {
+    BYTE* pData = nullptr;
+    m_captureClient->GetBuffer(&pData, &frames, &flags, NULL, NULL);
+
+    if (pData && frames > 0) {
+      float* pfData = (float*)pData;
+      for (UINT32 i = 0; i < frames; ++i) {
+        float leftChannel = pfData[i * 2];
+        float rightChannel = pfData[i * 2 + 1];
+        out.push_back(Vector2(leftChannel, rightChannel));
+      }
+    }
+    else {
+      //out.push_back(Vector2(0, 0));
+    }
+
+    m_captureClient->ReleaseBuffer(frames);
+    m_captureClient->GetNextPacketSize(&len);
+  }
+
+  return out;
+}
+
+void AudioCapture::process()
+{
+  UINT32 len = 0;
+  UINT32 frames = 0;
+  DWORD flags = 0;
+
+  m_captureClient->GetNextPacketSize(&len);
+
+  while (len > 0) {
+    BYTE* pData = nullptr;
+    m_captureClient->GetBuffer(&pData, &frames, &flags, NULL, NULL);
+
+    if (pData && frames > 0) {
+      float* pfData = (float*)pData;
+      for (UINT32 i = 0; i < frames; ++i) {
+        float leftChannel = pfData[i * 2];
+        float rightChannel = pfData[i * 2 + 1];
+        m_audioPlayback->push_frame(Vector2(leftChannel, rightChannel));
+      }
+    }
+    else {
+      m_audioPlayback->push_frame(Vector2(0, 0));
+    }
+
+    m_captureClient->ReleaseBuffer(frames);
+    m_captureClient->GetNextPacketSize(&len);
+  }
+
+}
+
+void AudioCapture::start(Ref<AudioStreamGeneratorPlayback> playback)
+{
+  m_audioPlayback = playback;
+
+  const auto hr = m_audioClient->Start();
+  if (FAILED(hr)) {
+    UtilityFunctions::printerr("Start failed:", hr);
+    return;
+  };
+}
+
+}
\ No newline at end of file
diff --git a/src/AudioCapture.h b/src/AudioCapture.h
new file mode 100644
index 0000000..940f589
--- /dev/null
+++ b/src/AudioCapture.h
@@ -0,0 +1,39 @@
+#pragma once
+
+#include <windows.h>
+#include <mmdeviceapi.h>
+#include <audioclient.h>
+
+#include <godot_cpp/classes/node.hpp>
+#include <godot_cpp/core/class_db.hpp>
+#include <godot_cpp/classes/audio_stream_generator.hpp>
+#include <godot_cpp/classes/audio_stream_generator_playback.hpp>
+
+namespace godot {
+
+class AudioCapture : public Node
+{
+	GDCLASS(AudioCapture, Node);
+
+protected:
+	static void _bind_methods();
+
+public:
+	AudioCapture();
+
+	Array getFrame() const;
+
+	void process();
+  void start(Ref<AudioStreamGeneratorPlayback> playback);
+
+private:
+	IAudioClient* m_audioClient = nullptr;
+	IAudioCaptureClient* m_captureClient = nullptr;
+
+  Ref<AudioStreamGenerator> m_audioStream;
+  Ref<AudioStreamGeneratorPlayback> m_audioPlayback;
+
+
+};
+
+}
diff --git a/src/register_types.cpp b/src/register_types.cpp
index 4079c7f..a278c6d 100644
--- a/src/register_types.cpp
+++ b/src/register_types.cpp
@@ -13,6 +13,7 @@
 
 #include "GodotOpus.h"
 #include "AudioProcessor.h"
+#include "AudioCapture.h"
 #include "GodotObs.h"
 
 using namespace godot;
@@ -25,6 +26,7 @@ void gdextension_initialize(ModuleInitializationLevel p_level)
 	{
 		ClassDB::register_class<Opus>();
 		ClassDB::register_class<AudioProcessor>();
+		ClassDB::register_class<AudioCapture>();
 		ClassDB::register_class<Obs>();
 	}
 }