AudioCaptureInternal.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "AudioCaptureCore.h"
#include "AudioCaptureCoreLog.h"
#include "Misc/App.h"
#include "Features/IModularFeatures.h"
 
namespace Audio
{
    // Null implementation for compiler
    class FNullAudioCaptureDevice : public IAudioCaptureStream
    {
    public:
        FNullAudioCaptureDevice() {}
 
        // Begin IAudioCaptureStream
        virtual bool GetCaptureDeviceInfo(FCaptureDeviceInfo& OutInfo, int32 DeviceIndex) override { return false; }
        virtual bool OpenAudioCaptureStream(const FAudioCaptureDeviceParams& InParams, FOnAudioCaptureFunction OnCapture, uint32 NumFramesDesired) override { return false; }
        virtual bool CloseStream() override { return false; }
        virtual bool StartStream() override { return false; }
        virtual bool StopStream() override { return false; }
        virtual bool AbortStream() override { return false; }
        virtual bool GetStreamTime(double& OutStreamTime) override { return false; }
        virtual int32 GetSampleRate() const override { return 0; }
        virtual bool IsStreamOpen() const override { return false; }
        virtual bool IsCapturing() const override { return false; }
        virtual void OnAudioCapture(void* InBuffer, uint32 InBufferFrames, double StreamTime, bool bOverflow) override {}
        virtual bool GetInputDevicesAvailable(TArray<FCaptureDeviceInfo>& OutDevices) override { return false; }
        // ~End IAudioCaptureStream
    };
 
    FORCEINLINE TUniquePtr<IAudioCaptureStream> FAudioCapture::CreateImpl()
    {
        IModularFeatures::Get().LockModularFeatureList();
        TArray<IAudioCaptureFactory*> AudioCaptureStreamFactories = IModularFeatures::Get().GetModularFeatureImplementations<IAudioCaptureFactory>(IAudioCaptureFactory::GetModularFeatureName());
        IModularFeatures::Get().UnlockModularFeatureList();
 
        // For now, just return the first audio capture stream implemented. We can make this configurable at a later point.
        if (AudioCaptureStreamFactories.Num() > 0 && AudioCaptureStreamFactories[0] != nullptr && FApp::CanEverRenderAudio())
        {
            return AudioCaptureStreamFactories[0]->CreateNewAudioCaptureStream();
        }
        else
        {
            UE_LOG(LogAudioCaptureCore, Display, TEXT("No Audio Capture implementations found. Audio input will be silent."));
            return TUniquePtr<IAudioCaptureStream>(new FNullAudioCaptureDevice());
        }
    }
 
} // namespace audio