The Unreal integration provides audio input to Wwise through the Wwise Audio Input Source Plug-in. In order to provide audio input to Wwise, classes must inherit from AkAudioInputComponent.

AkAudioInputComponent

AkAudioInputComponent 由 AkComponent 派生。It is a specialized AkComponent that you can use to provide audio input to Wwise. To do so, you must implement two key functions:

AkAudioInputComponent also has one Blueprint function, Post Associated Audio Input Event, which posts the component's AkAudioEvent to Wwise along with the associated AudioSamples callback and AudioFormat callback, using this component as the game object source.

Customizing Audio Input Behavior

You can write custom classes that derive from AkAudioInputComponent in order to implement custom audio input behavior. The following UAkVoiceInputComponent.h and UAkVoiceInputComponent.cpp examples show a class that takes microphone input and pipes it to the Wwise Sound Engine.

Before you can use these files in a C++ Unreal project, you must perform some initial setup. First, add the AkAudio and the Unreal Voice modules to the PublicDependencyModuleNames in the project's Build.cs file. 例如：

Next, add the following lines to the DefaultEngine.ini file:

After these setup steps are complete, add the desired custom behavior. In the following example, a class takes microphone input and sends it to Wwise.

注記： The sample code in this section is not intended for use in shipped games. It is only a short example of how to implement custom behavior. Here is an example of a customized AkVoiceInputComponent.h file: #pragma once #include "CoreMinimal.h" #include "AkAudioInputComponent.h" #include "Voice.h" #include "AkVoiceInputComponent.generated.h" /* */ UCLASS(ClassGroup = Audiokinetic, BlueprintType, hidecategories = (Transform, Rendering, Mobility, LOD, Component, Activation), meta = (BlueprintSpawnableComponent)) class WWISEDEMOGAME_API UAkVoiceInputComponent : public UAkAudioInputComponent { GENERATED_BODY() UAkVoiceInputComponent(const class FObjectInitializer& ObjectInitializer); virtual void TickComponent(float DeltaTime, enum ELevelTick TickType, FActorComponentTickFunction *ThisTickFunction) override; protected: /* 此函数会在 Wwise 声音引擎中注销此组件所属的 GameObject 后调用。*/ virtual void PostUnregisterGameObject() override; /* 音频回调。此回调将由 Wwise 声音引擎连续调用，并用于为声音引擎提供音频采样。*/ virtual bool FillSamplesBuffer(uint32 NumChannels, uint32 NumSamples, float** BufferToFill) override; /* 此回调用于为 Wwise 声音引擎提供所需音频格式。*/ virtual void GetChannelConfig(AkAudioFormat& AudioFormat) override; /* Unreal IVoiceCapture，用于获取话筒输入。*/ TSharedPtr<IVoiceCapture> VoiceCapture; /* 此数组会在每次 Voice Capture 传入新的缓冲数据时重置和重写。*/ TArray<uint8> IncomingRawVoiceData; /* 此数组会存管 Voice Capture 之前收集的所有音频数据。 在处理可用话筒数据时写入，在向 Wwise 引擎发送数据时读取并缩减。 建议不要缩减音频回调中的缓冲数据。请勿将此代码行用在发售的游戏中！*/ TArray<uint8> CollectedRawVoiceData; /* 此标记用于阻止将话筒数据写入正被读取的已收集数据缓冲区。*/ FThreadSafeBool bIsReadingVoiceData = false; }; Here is an example of a customized AkVoiceInputComponent.cpp file: #include "AkVoiceInputComponent.h" UAkVoiceInputComponent::UAkVoiceInputComponent(const class FObjectInitializer& ObjectInitializer) : UAkAudioInputComponent(ObjectInitializer) { CollectedRawVoiceData.Reset(); VoiceCapture = FVoiceModule::Get().CreateVoiceCapture(); } void UAkVoiceInputComponent::TickComponent(float DeltaTime, enum ELevelTick TickType, FActorComponentTickFunction *ThisTickFunction) { Super::TickComponent(DeltaTime, TickType, ThisTickFunction); if (!VoiceCapture.IsValid()) { return; } uint32 NumAvailableVoiceCaptureBytes = 0; EVoiceCaptureState::Type CaptureState = VoiceCapture->GetCaptureState(NumAvailableVoiceCaptureBytes); /* IVoiceCapture 会在每次 Tick 时更新其 EVoiceCaptureState。 我们可以在两次 Tick 之间通过该状态来辨别是否真的有要收集的新数据。*/ if (CaptureState == EVoiceCaptureState::Ok && NumAvailableVoiceCaptureBytes > 0) { uint32 NumVoiceCaptureBytesReturned = 0; IncomingRawVoiceData.Reset((int32)NumAvailableVoiceCaptureBytes); IncomingRawVoiceData.AddDefaulted(NumAvailableVoiceCaptureBytes); uint64 SampleCounter = 0; VoiceCapture->GetVoiceData(IncomingRawVoiceData.GetData(), NumAvailableVoiceCaptureBytes, NumVoiceCaptureBytesReturned, SampleCounter); if (NumVoiceCaptureBytesReturned > 0) { /* 在从收集的数据缓冲区读取数据时加以调节 */ while (bIsReadingVoiceData) {} CollectedRawVoiceData.Append(IncomingRawVoiceData); } } } bool UAkVoiceInputComponent::FillSamplesBuffer(uint32 NumChannels, uint32 NumSamples, float** BufferToFill) { if (!VoiceCapture.IsValid()) { return false; } const uint8 NumBytesPerSample = 2; const uint32 NumRequiredBytesPerChannel = NumSamples * NumBytesPerSample; const uint32 NumRequiredBytes = NumRequiredBytesPerChannel * NumChannels; int16 VoiceSample = 0; uint32 RawChannelIndex = 0; uint32 RawSampleIndex = 0; bIsReadingVoiceData = true; const int32 NumSamplesAvailable = CollectedRawVoiceData.Num() / NumBytesPerSample; const uint32 BufferSlack = (uint32)FMath::Max(0, (int32)(NumSamples * NumChannels) - NumSamplesAvailable); for (uint32 c = 0; c < NumChannels; ++c) { RawChannelIndex = c * NumRequiredBytesPerChannel; for (uint32 s = 0; s < NumSamples; ++s) { if (s >= (NumSamples - BufferSlack) / NumChannels) { /* 若 Wwise 引擎认为从 Voice Capture 收到的数据不足，则使用零来填补缺失采样。*/ BufferToFill[c][s] = 0.0f; } else { /* 将传入的话筒音频数据转换为带符号浮点数。*/ uint32 RawSampleDataMSBIndex = s * 2 + 1; uint32 RawSampleDataLSBIndex = s * 2; VoiceSample = (CollectedRawVoiceData[RawSampleDataMSBIndex] << 8) | CollectedRawVoiceData[RawSampleDataLSBIndex]; BufferToFill[c][s] = VoiceSample / (float)INT16_MAX; } } } const int32 NumBytesRead = (NumSamples - BufferSlack) * NumBytesPerSample; /* 注意：建议不要缩减音频回调中的缓冲数据。请勿将此代码行用在发售的游戏中！*/ CollectedRawVoiceData.RemoveAt(0, NumBytesRead); bIsReadingVoiceData = false; return true; } void UAkVoiceInputComponent::GetChannelConfig(AkAudioFormat& AudioFormat) { const int sampleRate = 16000; AudioFormat.uSampleRate = sampleRate; AudioFormat.channelConfig.SetStandard(AK_SPEAKER_SETUP_MONO); if (VoiceCapture.IsValid()) { /* 发送空白设备名称以使用默认设备。*/ if (!VoiceCapture->Init(FString(""), AudioFormat.uSampleRate, AudioFormat.channelConfig.uNumChannels)) { UE_LOG(LogTemp, Error, TEXT("Failed to initialize device for voice input!")); return; } VoiceCapture->Start(); } } void UAkVoiceInputComponent::PostUnregisterGameObject() { Super::PostUnregisterGameObject(); if (VoiceCapture.IsValid()) { VoiceCapture->Stop(); VoiceCapture->Shutdown(); } } After you add the class to an Unreal project, you can create a custom Blueprint class that has an AkVoiceInputComponent, and can call the Post Associated Audio Input Event Blueprint function (from base class AkAudioInputComponent) to start sending microphone data to Wwise. The following image shows part of the Blueprint for a custom Blueprint class, based on Actor, that has an AkVoiceInputComponent called AkVoiceInput.